verapamil (Rx)

Angina

Immediate release

• 80 mg PO q8hr initially; usual range: 80-120 mg PO q8hr; not to exceed 480 mg/day

Extended release

• Covera-HS: 180 mg/day PO at bedtime initially; maintenance: 180-540 mg/day PO at bedtime

Hypertension

Immediate release

• 80 mg PO q8hr initially; maintenance: 80-320 mg PO q12hr

Extended release

• Calan, Isoptin SR: 180 mg/day PO given in morning (120 mg/day initially if patient elderly or of small stature); for desired response, may be increased to 240 mg/day, then to 360 mg/day (either 180 mg q12hr or 240 mg in morning and 120 mg in evening)
• Verelan: 180 mg/day PO (120 mg/day initially if patient elderly or of small stature); for desired response, may be increased to 240 mg/day PO, then by 120 mg/day at weekly intervals; not to exceed 480 mg/day
• Verelan PM: 200 mg/day PO at bedtime (100 mg/day if patient elderly or of small stature); may be increased by 100 mg/day at weekly intervals as needed; not to exceed 400 mg/day
• Covera-HS: 180 mg/day PO at bedtime (120 mg/day initially if patient elderly or of small stature); for desired response, may be increased to 240 mg/day, then by 120 mg/day at weekly intervals; not to exceed 480 mg/day

Supraventricular Arrhythmia & Atrial Fibrillation/Flutter

2.5-5 mg IV over 2 minutes; 5-10 mg dose may be repeated after 15-30 minutes

Alternatively, 0.075-0.15 mg/kg (not to exceed 10 mg) IV over 2 minutes; dose may be repeated once 30 minutes after first dose  

Chronic Atrial Fibrillation & Paroxysmal Supraventricular Tachycardia

Treatment of chronic atrial fibrillation (rate control); prevention of paroxysmal supraventricular tachycardia

Immediate release: 240-480 mg/day PO divided q6-8hr

Tardive Dyskinesia

40 mg PO q8hr; may be titrated to 120 mg q8hr

Migraine (Off-label)

Prophylaxis

160-320 mg PO q6-8hr

Dosing Modifications

Renal impairment: Use with caution; monitor ECG; for Verelan PM, manufacturer recommends 100 mg at bedtime initially; if CrCl <10 mL/min, reduce dose by 25-50%

Hepatic impairment: In cirrhosis, reduce dose by 20-50% of normal for oral and IV administration

Supraventricular Tachycardia

1-15 years old: 0.1-0.3 mg/kg (not to exceed 5 mg) IV over 2 minutes; second dose (not to exceed 10 mg) may be given after 30 minutes

Alternatively (not well established), 4-8 mg/kg/day PO divided q8hr

In general, lower initial doses are warranted; doses should be adjusted on basis of clinical response

Angina

Immediate release: 80 mg PO q8hr initially; usual range: 80-120 mg PO q8hr; not to exceed 480 mg/day

Extended release (Covera-HS): 180 mg PO at bedtime initially; maintenance: 180-540 mg PO at bedtime

Hypertension

Immediate release: 40 mg PO q8hr initially; maintenance: 80-320 mg PO q12hr

Extended release (Calan SR, Isoptin SR, Verelan): 120 mg/day PO given in morning

Extended release (Covera-HS): 180 mg/day PO at bedtime

Extended release (Verelan PM): 100 mg/day PO at bedtime

Contraindicated (6)

• dantrolene

  dantrolene, verapamil. Either increases toxicity of the other by Mechanism: pharmacodynamic synergism. Contraindicated. Rare incidence of cardiovascular collapse and marked hyperkalemia observed when coadministered; may be higher risk with nondihydropyridine calcium channel blockers.

• fezolinetant

  verapamil will increase the level or effect of fezolinetant by affecting hepatic enzyme CYP1A2 metabolism. Contraindicated. Fezolinetant AUC and peak plasma concentration are increased if coadministered with drugs that are weak, moderate, or strong CYP1A2 inhibitors

• flibanserin

  verapamil will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of flibanserin with moderate or strong CYP3A4 inhibitors is contraindicated. Severe hypotension or syncope can occur.

• lomitapide

  verapamil increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Increases lomitapide levels several folds.

• lonafarnib

  verapamil will increase the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Lonafarnib is a sensitive CYP3A4 substrate. Coadministration with strong or moderate CYP3A4 inhibitors is contraindicated.

• pimozide

  verapamil increases levels of pimozide by decreasing metabolism. Contraindicated. Risk of QT interval prolongation.

Serious - Use Alternative (102)

• abametapir

  abametapir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP3A4 substrates. If not feasible, avoid use of abametapir.

• afatinib

  verapamil increases levels of afatinib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. Reduce afatinib daily dose by 10 mg if not tolerated when coadministered with P-gp inhibitors.

• alosetron

  verapamil will increase the level or effect of alosetron by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug.

• apalutamide

  apalutamide will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.

• atenolol

  verapamil, atenolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• avapritinib

  verapamil will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of avapritinib with strong CYP3A4 inhibitors.

• axitinib

  verapamil increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with moderate CYP3A4 inhibitors, monitor closely and reduce dose if necessary .

• betaxolol

  verapamil, betaxolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• bisoprolol

  verapamil, bisoprolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• bosutinib

  verapamil increases levels of bosutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  verapamil increases levels of bosutinib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• carbamazepine

  carbamazepine will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ceritinib

  ceritinib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• cimetidine

  cimetidine will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• cobimetinib

  verapamil will increase the level or effect of cobimetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If concurrent short term (14 days or less) use of moderate CYP3A inhibitors is unavoidable for patients who are taking cobimetinib 60 mg, reduce the cobimetinib dose to 20 mg. After discontinuation of a moderate CYP3A inhibitor, resume cobimetinib 60 mg. Use an alternative to a moderate CYP3A inhibitor in patients who are taking a reduced dose of cobimetinib (40 or 20 mg daily).

• colchicine

  verapamil will increase the level or effect of colchicine by Other (see comment). Avoid or Use Alternate Drug. Colchicine is a P-gp and CYP3A4 substrate. Avoid use with drugs that are both P-gp and strong CYP3A4 inhibitors. If coadministration is necessary, decrease colchicine dose or frequency as recommended in prescribing information. Use of any colchicine product in conjunction with strong CYP3A4 inhibitors is contraindicated in patients with renal or hepatic impairment.

• cyclobenzaprine

  verapamil and cyclobenzaprine both increase serotonin levels. Avoid or Use Alternate Drug.

• digoxin

  verapamil increases levels of digoxin by decreasing renal clearance. Avoid or Use Alternate Drug.

• dihydroergotamine

  verapamil will increase the level or effect of dihydroergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• dihydroergotamine intranasal

  verapamil will increase the level or effect of dihydroergotamine intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• dronedarone

  verapamil will increase the level or effect of dronedarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• duloxetine

  verapamil will increase the level or effect of duloxetine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug.

• edoxaban

  verapamil will increase the level or effect of edoxaban by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. Dose adjustment may be required with strong P-gp inhibitors. DVT/PE treatment: Decrease dose to 30 mg PO once daily. NVAF: No dose reduction recommended

• elacestrant

  verapamil will increase the level or effect of elacestrant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• eliglustat

  verapamil increases levels of eliglustat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Moderate CYP3A4 inhibitors are not recommended with eliglustat poor or intermediate metabolizers; reduce eliglustat dose from 84 mg BID to 84 mg once daily in extensive metabolizers .

• encorafenib

  verapamil will increase the level or effect of encorafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If concomitant use of a moderate CYP3A4 inhibitor is unavoidable, reduce encorafenib dose to one-half of the dose (eg, reduce from 450 mg/day to 225 mg/day). After discontinuing the inhibitor for 3-5 elimination half-lives, resume previous encorafenib dose.

• entrectinib

  verapamil will increase the level or effect of entrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of moderate CYP3A4 inhibitors with entrectinib, a CYP3A4 substrate. If coadministration unavoidable, reduce dose to 200 mg/day for patients aged 12 y or older with BSA >1.50m2. Resume previous entrectinib dose after discontinuing moderate CYP3A inhibitor for 3-5 elimination half-lives.

• erdafitinib

  erdafitinib will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

• ergotamine

  verapamil will increase the level or effect of ergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• erythromycin base

  erythromycin base will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  verapamil will increase the level or effect of erythromycin base by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• erythromycin ethylsuccinate

  erythromycin ethylsuccinate will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  verapamil will increase the level or effect of erythromycin ethylsuccinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• erythromycin lactobionate

  erythromycin lactobionate will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  verapamil will increase the level or effect of erythromycin lactobionate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• erythromycin stearate

  erythromycin stearate will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  verapamil will increase the level or effect of erythromycin stearate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• esmolol

  verapamil, esmolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• everolimus

  verapamil will increase the level or effect of everolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Concomitant use of a moderate 3A4 inhibitor such as verapamil may significantly increase the plasma concentrations of everolimus following oral administration.
  
  verapamil will increase the level or effect of everolimus by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. Everolimus prescribing information lists indication-specific dosing recommendations.
  
  verapamil, everolimus. Either increases levels of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: With concomitant use of mTOR inhibitors, consider appropriate dose reductions of both medications.

• fentanyl

  verapamil will increase the level or effect of fentanyl by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

• fentanyl intranasal

  verapamil will increase the level or effect of fentanyl intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

• fentanyl transdermal

  verapamil will increase the level or effect of fentanyl transdermal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

• fentanyl transmucosal

  verapamil will increase the level or effect of fentanyl transmucosal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

• fexinidazole

  fexinidazole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.

• ibrutinib

  verapamil increases levels of ibrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of ibrutinib and strong CYP3A4 inhibitors. If a strong CYP3A4 inhibitor must be used short-term (eg, anti-infectives for =7 days), interrupt ibrutinib therapy until strong CYP3A4 inhibitor is discontinued.

• idelalisib

  idelalisib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates

• infigratinib

  verapamil will increase the level or effect of infigratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• irinotecan

  verapamil will increase the level or effect of irinotecan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• irinotecan liposomal

  verapamil will increase the level or effect of irinotecan liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• itraconazole

  itraconazole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Observe the patient for development of toxicity associated with verapamil (peripheral edema, dizziness, hypotension, flushing, headache). Consider reducing the dose of verapamil or withdrawing one of the agents.

• ivabradine

  verapamil will increase the level or effect of ivabradine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of ivabradine with moderate CYP3A4 inhibitors.

• ivosidenib

  ivosidenib will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternative therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.

• larotrectinib

  verapamil will increase the level or effect of larotrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• lasmiditan

  lasmiditan increases levels of verapamil by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• lemborexant

  verapamil will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of lemborexant with moderate or strong CYP3A inhibitors.

• levobunolol

  verapamil, levobunolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• lofexidine

  lofexidine, verapamil. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid coadministration with other drugs that decrease pulse or blood pressure to mitigate risk of excessive bradycardia and hypotension.

• lopinavir

  lopinavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• lovastatin

  verapamil will increase the level or effect of lovastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Do not exceed 20 mg of lovastatin

• lurbinectedin

  verapamil will increase the level or effect of lurbinectedin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• mavacamten

  verapamil, mavacamten. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Expect additive negative inotropic effects of mavacamten and other drugs that reduce cardiac contractility.

• metoprolol

  verapamil, metoprolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• midazolam intranasal

  verapamil will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of moderate CYP3A4 inhibitors with midazolam intranasal causes higher midazolam systemic exposure, which may prolong sedation.

• mobocertinib

  verapamil will increase the level or effect of mobocertinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If use of moderate CYP3A4 inhibitor unavoidable, reduce mobocertinib dose by ~50% (eg, 160 to 80 mg); closely monitor QTc interval.

• nadolol

  verapamil, nadolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• naloxegol

  verapamil will increase the level or effect of naloxegol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministation of naloxegol with moderate CYP3A4 inhibitors is unavoidable, reduce naloxegol dose to 12.5 mg qDay

• nebivolol

  verapamil, nebivolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• nefazodone

  nefazodone will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• neratinib

  verapamil will increase the level or effect of neratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of neratinib with strong/moderate CYP3A4 inhibitors.

• olaparib

  verapamil will increase the level or effect of olaparib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with moderate CYP3A inhibitors cannot be avoided, reduce olaparib dose to 200 mg (capsule) or 150 mg (tablet) PO BID. Do not substitute tablets with capsules.

• omaveloxolone

  verapamil will increase the level or effect of omaveloxolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unavoidable, reduce omaveloxolone dose to 100 mg/day. Closely monitor for adverse effects. If adverse effects emerge, further reduce to 50 mg/day.

• ozanimod

  ozanimod increases toxicity of verapamil by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Avoid or Use Alternate Drug. Because the active metabolite of ozanimod inhibits MAO-B in vitro, there is a potential for serious adverse reactions, including hypertensive crisis. Therefore, coadministration of ozanimod with drugs that can increase norepinephrine or serotonin is not recommended. Monitor for hypertension with concomitant use.

• pacritinib

  verapamil will increase the level or effect of pacritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• pazopanib

  verapamil will increase the level or effect of pazopanib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of pazopanib with strong CYP3A4 inhibitors if possible; if must coadminister, decrease pazopanib dose to 400 mg/day

• pemigatinib

  verapamil will increase the level or effect of pemigatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong or moderate CYP3A4 inhibitors is unavoidable, reduce pemigatinib dose (refer to drug monograph dosage modifications). After discontinuing the CYP3A4 inhibitor for 3 elimination half-lives, may resume previous pemigatinib dose.

• pexidartinib

  verapamil will increase the level or effect of pexidartinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong or moderate CYP3A4 inhibitors is unavoidable, reduce pexidartinib dose (refer to drug monograph dosage modifications). After discontinuing the CYP3A4 inhibitor for 3 elimination half-lives, may resume previous pexidartinib dose.

• pomalidomide

  verapamil increases levels of pomalidomide by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• ponesimod

  ponesimod, verapamil. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Consult cardiologist if considering treatment. Generally, should not be initiated in patients who are concurrently taking QT prolonging drugs with known arrhythmogenic properties, such as HR-lowering calcium channel blockers (eg, verapamil, diltiazem).

• propranolol

  verapamil, propranolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• ranolazine

  verapamil will increase the level or effect of ranolazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• rifabutin

  rifabutin will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• rifampin

  rifampin will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• rimegepant

  verapamil will increase the level or effect of rimegepant by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• riociguat

  verapamil will increase the level or effect of riociguat by decreasing metabolism. Avoid or Use Alternate Drug. Coadministration of riociguat (substrate of CYP isoenzymes 1A1, 2C8, 3A, 2J2) with strong CYP inhibitors may require a decreased initial dose of 0.5 mg PO TID; monitor for signs of hypotension and reduce dose if needed

• saquinavir

  saquinavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• selumetinib

  verapamil will increase the level or effect of selumetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong or moderate CYP3A4 inhibitors cannot be avoided, reduce selumetinib dosage (refer to selumetinib monograph for further information). After discontinuation of the strong or moderate CYP3A4 inhibitor for 3 elimination half-lives, resume selumetinib dose that was taken before initiating the inhibitor.

• silodosin

  verapamil will increase the level or effect of silodosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• simvastatin

  verapamil will increase the level or effect of simvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Do not exceed simvastatin 10 mg daily when given concurrently. Potential for increased risk of myopathy/rhabdomyolysis.

• siponimod

  siponimod, verapamil. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.
  
  verapamil will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• sirolimus

  verapamil will increase the level or effect of sirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  verapamil will increase the level or effect of sirolimus by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.
  
  verapamil, sirolimus. Either increases levels of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: With concomitant use of mTOR inhibitors, consider appropriate dose reductions of both medications.

• sotalol

  verapamil, sotalol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• sotorasib

  sotorasib will decrease the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If use is unavoidable, refer to the prescribing information of the P-gp substrate for dosage modifications.

• St John's Wort

  St John's Wort will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• sulbactam/durlobactam

  verapamil will increase the level or effect of sulbactam/durlobactam by Other (see comment). Avoid or Use Alternate Drug. Sulbactam is predicted to have active secretion by OATP1 as a significant portion of total clearance; therefore, inhibition of OAT1 may increase sulbactam plasma concentrations

• talazoparib

  verapamil will increase the level or effect of talazoparib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration with certain P-gp inhibitors (ie, amiodarone, carvedilol, clarithromycin, itraconazole, verapamil) cannot be avoided, reduce talazoparib dose to 0.75 mg qDay. Once P-gp inhibitors are discontinued, increase talazoparib dose (after 3-5 half-lives of the inhibitor) to dose used prior to initiating the P-gp inhibitor(s).

• tazemetostat

  verapamil will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of tazemetostat with moderate CYP3A4 inhibitors. If coadministration is unavoidable, reduce tazemetostat current dose (see drug monograph Dosage Modifications).

• temsirolimus

  verapamil will increase the level or effect of temsirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  verapamil, temsirolimus. Either increases levels of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: With concomitant use of mTOR inhibitors, consider appropriate dose reductions of both medications.

• tepotinib

  tepotinib will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If concomitant use unavoidable, reduce the P-gp substrate dosage if recommended in its approved product labeling.

• timolol

  verapamil, timolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• tizanidine

  verapamil will increase the level or effect of tizanidine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug.

• tolvaptan

  verapamil will increase the level or effect of tolvaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• topotecan

  verapamil will increase the level or effect of topotecan by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. Product labeling for PO topotecan recommends avoiding concomitant use of P-gp inhibitors; the interaction with IV topotecan may be less severe but is still likely of clinical significance

• tucatinib

  tucatinib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.

• venetoclax

  verapamil will increase the level or effect of venetoclax by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If a moderate CYP3A inhibitor must be used, reduce the venetoclax dose by at least 50%. Monitor more closely for signs of venetoclax toxicities.
  
  verapamil will increase the level or effect of venetoclax by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If a P-gp inhibitor must be used, reduce the venetoclax dose by at least 50%. Monitor more closely for signs of venetoclax toxicities.

• vilazodone

  verapamil increases levels of vilazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If intolerable adverse effects occur when coadministered with moderate CYP3A4 inhibitors, reduce daily dose to 20 mg.

• vortioxetine

  verapamil, vortioxetine. Either increases effects of the other by serotonin levels. Avoid or Use Alternate Drug.

• voxelotor

  voxelotor will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.

Monitor Closely (300)

• acalabrutinib

  verapamil will increase the level or effect of acalabrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Decrease acalabrutinib dose to 100 mg once daily if coadministered with a moderate CYP3A inhibitor.

• acebutolol

  acebutolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• aldesleukin

  aldesleukin increases effects of verapamil by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

• alfentanil

  verapamil will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. The risk of significant hypotension and/or bradycardia during therapy with alfentanil may be increased in patients receiving calcium-channel blockers.

• alfuzosin

  alfuzosin and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• aliskiren

  verapamil will increase the level or effect of aliskiren by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of aliskiren by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• almotriptan

  verapamil will increase the level or effect of almotriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• alprazolam

  verapamil will increase the level or effect of alprazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• amifostine

  amifostine, verapamil. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration with blood pressure lowering agents may increase the risk and severity of hypotension associated with amifostine. When amifostine is used at chemotherapeutic doses, withhold blood pressure lowering medications for 24 hr prior to amifostine; if blood pressure lowering medication cannot be withheld, do not administer amifostine.

• amikacin

  verapamil will increase the level or effect of amikacin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• amiodarone

  verapamil will increase the level or effect of amiodarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  amiodarone will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.
  
  amiodarone, verapamil. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of cardiotoxicity with bradycardia.

• amitriptyline

  verapamil will increase the level or effect of amitriptyline by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. The frequency and severity of amitriptyline adverse effects (sedation, anticholinergic effects and orthostatic hypotension) may be increased. Cardiac dysrhythmic effects may be additive.

• amlodipine

  amlodipine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• amobarbital

  amobarbital will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• apixaban

  verapamil will increase the level or effect of apixaban by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Verapamil also inhibits P-gp activity, which can further increase apixaban serum levels; since both pathways of apixaban elimination are affected, patients with renal impairment receiving apixaban with drugs that are combined P-gp and moderate CYP3A4 inhibitors may increase exposure compared to patients with normal renal function; monitor for bleeding.

• aprepitant

  aprepitant will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• aripiprazole

  verapamil will increase the level or effect of aripiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• armodafinil

  armodafinil will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• artemether/lumefantrine

  verapamil will increase the level or effect of artemether/lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• asenapine

  asenapine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• atazanavir

  atazanavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of atazanavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Caution advised, may increase risk of AV block

• atenolol

  atenolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• atogepant

  verapamil will increase the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• atorvastatin

  verapamil will increase the level or effect of atorvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of atorvastatin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• avanafil

  verapamil will increase the level or effect of avanafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inhibitors may reduce avanafil clearance increasing systemic exposure to avanafil; increased levels may result in increased associated adverse events; the maximum recommended dose of STENDRA is 50 mg, not to exceed once every 24 hours for patients taking concomitant moderate CYP3A4 inhibitors

• azithromycin

  azithromycin will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• bazedoxifene/conjugated estrogens

  verapamil will increase the level or effect of bazedoxifene/conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of bazedoxifene/conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• berotralstat

  berotralstat will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor or titrate P-gp substrate dose if coadministered.

• betaxolol

  betaxolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• betrixaban

  verapamil increases levels of betrixaban by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Decrease betrixaban dose to 80 mg PO once, then 40 mg PO qDay if coadministered with a P-gp inhibitor.

• bisoprolol

  bisoprolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• bortezomib

  verapamil will increase the level or effect of bortezomib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• bosentan

  bosentan will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• bosutinib

  bosutinib increases levels of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• bretylium

  verapamil, bretylium. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Each drug may cause hypotension.

• brexpiprazole

  verapamil will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP3A4 inhibitor PLUS a strong/moderate CYP2D6 inhibitor.

• budesonide

  verapamil will increase the level or effect of budesonide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  budesonide will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of budesonide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• buprenorphine subdermal implant

  verapamil will increase the level or effect of buprenorphine subdermal implant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor patients already on buprenorphine subdermal implant who require newly-initiated treatment with CYP3A4 inhibitors for signs and symptoms of overmedication. If the dose of the concomitant CYP3A4 inhibitor cannot be reduced or discontinued, implant removal may be necessary and the patient should then be treated with a buprenorphine dosage form that permits dose adjustments. If a CYP3A4 inhibitor is discontinued in a patient who has been stabilized on buprenorphine, monitor the patient for withdrawal.

• buprenorphine, long-acting injection

  verapamil will increase the level or effect of buprenorphine, long-acting injection by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Patients who transfer to buprenorphine long-acting injection from transmucosal buprenorphine coadministered with CYP3A4 inhibitors should be monitored to ensure buprenorphine plasma levels are adequate. Within 2 weeks, if signs and symptoms of buprenorphine toxicity or overdose occur and the concomitant CYP3A4 inhibitor cannot be reduced or discontinued, transition the patient back to a buprenorphine formulation that permits dose adjustments.

• buspirone

  verapamil will increase the level or effect of buspirone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Consider lower buspirone doses.

• butabarbital

  butabarbital will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• butalbital

  butalbital will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cabazitaxel

  verapamil will increase the level or effect of cabazitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Caution should be exercised with concomitant use of moderate CYP3A4 inhibitors.

• cabozantinib

  verapamil will increase the level or effect of cabozantinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• calcium acetate

  calcium acetate decreases effects of verapamil by pharmacodynamic antagonism. Use Caution/Monitor.

• calcium carbonate

  calcium carbonate decreases effects of verapamil by pharmacodynamic antagonism. Use Caution/Monitor.

• calcium chloride

  calcium chloride decreases effects of verapamil by pharmacodynamic antagonism. Use Caution/Monitor.

• calcium citrate

  calcium citrate decreases effects of verapamil by pharmacodynamic antagonism. Use Caution/Monitor.

• calcium gluconate

  calcium gluconate decreases effects of verapamil by pharmacodynamic antagonism. Use Caution/Monitor.

• cannabidiol

  verapamil will increase the level or effect of cannabidiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Consider reducing the cannabidiol dose when coadministered with a moderate CYP3A4 inhibitor.

• carbamazepine

  verapamil will increase the level or effect of carbamazepine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor plasma levels when used concomitantly

• carbidopa

  carbidopa increases effects of verapamil by pharmacodynamic synergism. Use Caution/Monitor. Therapy with carbidopa, given with or without levodopa or carbidopa-levodopa combination products, is started, dosage adjustment of the antihypertensive drug may be required.

• carvedilol

  carvedilol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• celiprolol

  celiprolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• ceritinib

  verapamil increases levels of ceritinib by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• chloramphenicol

  chloramphenicol will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

• cilostazol

  verapamil will increase the level or effect of cilostazol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Consider decreasing the cilostazol dose to 50 mg twice a day.

• cimetidine

  cimetidine will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.

• cinacalcet

  verapamil will increase the level or effect of cinacalcet by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• clarithromycin

  clarithromycin will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increased effect of calcium channel blockers may lead to hypotension, edema, decreased HR, and acute kidney injury due to reduced renal blood flow

• clevidipine

  clevidipine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• clomipramine

  verapamil will increase the level or effect of clomipramine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• clonidine

  clonidine, verapamil. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Sinus bradycardia resulting in hospitalization and pacemaker insertion has been reported in association with the use of clonidine concurrently with verapamil. Monitor heart rate in patients receiving concomitant verapamil and clonidine.
  
  verapamil, clonidine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Sinus bradycardia resulting in hospitalization and pacemaker insertion has been reported in association with the use of clonidine concurrently with verapamil. Monitor heart rate in patients receiving concomitant verapamil and clonidine.

• clopidogrel

  verapamil will decrease the level or effect of clopidogrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Inhibition of CYP3A4 will reduce clopidogrel bioactivation

• clozapine

  verapamil will increase the level or effect of clozapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of clozapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cobicistat

  cobicistat will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• conivaptan

  conivaptan will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• conjugated estrogens

  verapamil will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• conjugated estrogens, vaginal

  verapamil will increase the level or effect of conjugated estrogens, vaginal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of conjugated estrogens, vaginal by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• cortisone

  verapamil will increase the level or effect of cortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  cortisone will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of cortisone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• crizotinib

  crizotinib increases levels of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.
  
  crizotinib increases levels of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  verapamil increases levels of crizotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Caution should be exercised with concomitant use of moderate CYP3A inhibitors. .

• crofelemer

  crofelemer increases levels of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.

• cyclosporine

  verapamil, cyclosporine. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Verapamil and cyclosporine may inhibit CYP3A4 metabolism. Coadministration of verapamil and cyclosporine may increase plasma concentrations of either drugs.

• dabigatran

  verapamil will increase the level or effect of dabigatran by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Atrial fibrillation: Avoid coadministering dabigatran with P-gp inhibitors if CrCl <30 mL/min. DVT/PE treatment: Avoid coadministering dabigatran with P-gp inhibitors if CrCl <50 mL/min

• dabrafenib

  dabrafenib will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

• daridorexant

  verapamil will increase the level or effect of daridorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Daridorexant dose should not exceed 25 mg per night when coadministered with moderate CYP3A4 inhibitors.

• darifenacin

  darifenacin will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• darunavir

  darunavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• dasatinib

  dasatinib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• daunorubicin

  verapamil will increase the level or effect of daunorubicin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• deferasirox

  deferasirox will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• deflazacort

  verapamil will increase the level or effect of deflazacort by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Decrease deflazacort dose to one-third of the recommended dose if coadministered with moderate or strong CYP3A4 inhibitors.
  
  verapamil will increase the level or effect of deflazacort by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• dexamethasone

  verapamil will increase the level or effect of dexamethasone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  dexamethasone will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of dexamethasone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• DHEA, herbal

  DHEA, herbal will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• diazepam

  verapamil will increase the level or effect of diazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• diazepam intranasal

  verapamil will increase the level or effect of diazepam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong or moderate CYP3A4 inhibitors may decrease rate of diazepam elimination, thereby increasing adverse reactions to diazepam.

• dienogest/estradiol valerate

  verapamil will increase the level or effect of dienogest/estradiol valerate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor for potential adverse effects such as nausea, irregular uterine bleeding, breast tenderness and headache.

• digoxin

  verapamil will increase the level or effect of digoxin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Toxicity characterized by gastrointestinal and neuropsychiatric symptoms, and cardiac arrhythmias may result.
  
  digoxin will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.

• diltiazem

  diltiazem will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of diltiazem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. These agents have additive hypotensive effects that may be beneficial however, it is important to monitor patients carefully.
  
  diltiazem and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor. Antihypertensives may enhance the hypotensive effects of other antihypertensive agents when used together.

• disopyramide

  verapamil will increase the level or effect of disopyramide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Avoid disopyramide administration within 48 hours before or 24 hours after verapamil administration.

• docetaxel

  verapamil will increase the level or effect of docetaxel by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• dofetilide

  dofetilide will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.

• doxazosin

  doxazosin and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• doxorubicin

  verapamil will increase the level or effect of doxorubicin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil increases levels of doxorubicin by decreasing metabolism. Use Caution/Monitor. Coadministration of doxorubicin and calcium channel blockers may increase the risk of doxorubicin cardiotoxicity. .

• doxorubicin liposomal

  verapamil will increase the level or effect of doxorubicin liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil increases toxicity of doxorubicin liposomal by decreasing metabolism. Use Caution/Monitor. Coadministration of doxorubicin and calcium channel blockers may increase the risk of doxorubicin cardiotoxicity. .

• dronedarone

  dronedarone will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• duvelisib

  duvelisib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with duvelisib increases AUC of a sensitive CYP3A4 substrate which may increase the risk of toxicities of these drugs. Consider reducing the dose of the sensitive CYP3A4 substrate and monitor for signs of toxicities of the coadministered sensitive CYP3A substrate.
  
  verapamil will increase the level or effect of duvelisib by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• efavirenz

  efavirenz will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• elagolix

  elagolix will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  elagolix decreases levels of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.

• eletriptan

  verapamil will increase the level or effect of eletriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• eliglustat

  eliglustat increases levels of verapamil by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the P-gp substrate and titrate to clinical effect.

• elvitegravir/cobicistat/emtricitabine/tenofovir DF

  elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.

• encorafenib

  encorafenib, verapamil. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.

• enzalutamide

  enzalutamide will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• eplerenone

  verapamil will increase the level or effect of eplerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Plasma concentrations and pharmacologic or toxic effects of eplerenone may be increased by verapamil.

• erlotinib

  verapamil will increase the level or effect of erlotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• eslicarbazepine acetate

  eslicarbazepine acetate will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil decreases levels of eslicarbazepine acetate by increasing metabolism. Modify Therapy/Monitor Closely.

• esmolol

  esmolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• estradiol

  verapamil will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• estrogens conjugated synthetic

  verapamil will increase the level or effect of estrogens conjugated synthetic by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of estrogens conjugated synthetic by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• estrogens esterified

  verapamil will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• estropipate

  verapamil will increase the level or effect of estropipate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of estropipate by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• ethanol

  verapamil increases levels of ethanol by decreasing metabolism. Use Caution/Monitor.

• etonogestrel

  verapamil will increase the level or effect of etonogestrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• etoposide

  verapamil will increase the level or effect of etoposide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• etravirine

  verapamil will increase the level or effect of etravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  etravirine will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• everolimus

  everolimus will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Everolimus prescribing information lists indication-specific dosing recommendations.

• fedratinib

  fedratinib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• felodipine

  verapamil will increase the level or effect of felodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  felodipine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• fesoterodine

  verapamil will increase the level or effect of fesoterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• finerenone

  verapamil will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor serum potassium during initiation and dosage adjustment of either finererone or moderate CYP3A4 inhibitors. Adjust finererone dosage as needed.

• fluconazole

  fluconazole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fludrocortisone

  verapamil will increase the level or effect of fludrocortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  fludrocortisone will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of fludrocortisone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• fluvoxamine

  fluvoxamine will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fosamprenavir

  fosamprenavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fosaprepitant

  fosaprepitant will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fosphenytoin

  fosphenytoin will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fostamatinib

  fostamatinib will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Concomitant use of fostamatinib may increase concentrations of P-gp substrates. Monitor for toxicities of the P-gp substrate drug that may require dosage reduction when given concurrently with fostamatinib.

• gentamicin

  verapamil will increase the level or effect of gentamicin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• glecaprevir/pibrentasvir

  verapamil will increase the level or effect of glecaprevir/pibrentasvir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  glecaprevir/pibrentasvir will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• grapefruit

  grapefruit will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• green tea

  verapamil increases levels of green tea by decreasing elimination. Use Caution/Monitor. (Caffeine). Verapamil reduces clearance of caffeine and increases serum caffeine concentrations, presumably via inhibition of hepatic metabolism. May advise patients to limit or minimize the intake of caffeinated products to minimize caffeine-related side effects.

• griseofulvin

  griseofulvin will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• guanfacine

  verapamil will increase the level or effect of guanfacine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong or moderate CYP3A4 inhibitors significantly increase guanfacine plasma concentrations. FDA-approved labeling for extended-release (ER) guanfacine recommends that, if coadministered, the guanfacine dosage should be decreased to half of the recommended dose. Specific recommendations for immediate-release (IR) guanfacine are not available.

• hawthorn

  hawthorn increases effects of verapamil by pharmacodynamic synergism. Use Caution/Monitor.

• hydrocortisone

  verapamil will increase the level or effect of hydrocortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  hydrocortisone will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of hydrocortisone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• hydroxyprogesterone caproate (DSC)

  verapamil will increase the level or effect of hydroxyprogesterone caproate (DSC) by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ifosfamide

  verapamil decreases effects of ifosfamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Use of a CYP3A4 inhibitor may decrease metabolism of ifosfamide, potentially reducing ifosfamide therapeutic effects.

• iloperidone

  verapamil will increase the level or effect of iloperidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  iloperidone increases levels of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.

• imatinib

  verapamil will increase the level or effect of imatinib by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• imipramine

  verapamil will increase the level or effect of imipramine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of imipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. TCA level may be increased.

• indacaterol, inhaled

  verapamil increases levels of indacaterol, inhaled by Other (see comment). Use Caution/Monitor. Comment: Data suggests that systemic clearance is influenced by modulation of both P-gp and CYP3A4 activities. No dose adjustment is warranted at the 75 mcg dose.

• indinavir

  indinavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of indinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of indinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• irinotecan

  verapamil will increase the level or effect of irinotecan by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• irinotecan liposomal

  verapamil will increase the level or effect of irinotecan liposomal by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• isavuconazonium sulfate

  verapamil will increase the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• isoniazid

  isoniazid will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• isradipine

  isradipine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• istradefylline

  istradefylline will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.
  
  istradefylline will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of P-gp substrates in clinical trials. Consider dose reduction of sensitive P-gp substrates.

• itraconazole

  verapamil will increase the level or effect of itraconazole by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  itraconazole will increase the level or effect of verapamil by Other (see comment). Modify Therapy/Monitor Closely. CCBs elicit negative inotropic effects which may be additive to those of itraconazole; additionally, itraconazole can inhibit the metabolism of calcium channel blockers. Monitor for adverse reactions. Concomitant drug dose reduction may be necessary.

• ivabradine

  verapamil, ivabradine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Most patients receiving ivabradine will also be treated with a beta-blocker. The risk of bradycardia increases with coadministration of drugs that slow heart rate (eg, digoxin, amiodarone, beta-blockers). Monitor heart rate in patients taking ivabradine with other negative chronotropes.

• ivacaftor

  verapamil will increase the level or effect of ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce ivacaftor dose if coadministered with moderate CYP3A4 inhibitors. See specific ivacaftor-containing product for precise dosage modification.
  
  ivacaftor increases levels of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Ivacaftor and its M1 metabolite has the potential to inhibit P-gp; may significantly increase systemic exposure to sensitive P-gp substrates with a narrow therapeutic index.

• ivermectin

  verapamil will increase the level or effect of ivermectin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• ivosidenib

  verapamil will increase the level or effect of ivosidenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration with moderate CYP3A4 inhibitors may increase ivosidenib plasma concentrations, thus increasing the risk of QTc prolongation. Monitor for increased risk of QTc interval prolongation.

• ixabepilone

  verapamil will increase the level or effect of ixabepilone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ketoconazole

  ketoconazole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• labetalol

  labetalol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• lapatinib

  lapatinib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of lapatinib by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• lefamulin

  verapamil will increase the level or effect of lefamulin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor for adverse effects if lefamulin is coadministered with moderate CYP3A inhibitors.

• lenacapavir

  lenacapavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lencapavir may increase CYP3A4 substrates initiated within 9 months after last SC dose of lenacapavir, which may increase potential risk of adverse reactions of CYP3A4 substrates.

• levamlodipine

  verapamil will increase the level or effect of levamlodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with moderate and strong CYP3A inhibitors results in increased systemic exposure to amlodipine and may require dose reduction. Monitor for symptoms of hypotension and edema when amlodipine is coadministered with CYP3A inhibitors to determine the need for dose adjustment.

• levodopa

  levodopa increases effects of verapamil by pharmacodynamic synergism. Use Caution/Monitor. Consider decreasing dosage of antihypertensive agent.

• levoketoconazole

  levoketoconazole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• lidocaine

  verapamil will increase the level or effect of lidocaine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• lomitapide

  lomitapide increases levels of verapamil by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Consider reducing dose when used concomitantly with lomitapide.

• loperamide

  verapamil will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• lopinavir

  verapamil will increase the level or effect of lopinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• loratadine

  verapamil will increase the level or effect of loratadine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• lorlatinib

  lorlatinib will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• lovastatin

  verapamil will increase the level or effect of lovastatin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Avoid concomitant use of verapamil and lovastatin if possible. If used together, use lower doses of lovastatin and monitor for lovastatin toxicity (myositis, rhabdomyolysis).

• lumateperone

  verapamil will increase the level or effect of lumateperone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce lumateperone dose to 21 mg/day if coadministered with moderate CYP3A4 inhibitors.

• lumefantrine

  verapamil will increase the level or effect of lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• lurasidone

  verapamil increases levels of lurasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Manufacturer recommends decreasing starting dose of lurasidone to 20 mg/day and maximum daily dose of lurasidone 80 mg when coadministered with moderate CYP3A4 inhibitors. Concurrent use may increase risk of lurasidone-related adverse reactions.
  
  lurasidone increases effects of verapamil by Other (see comment). Use Caution/Monitor. Comment: Potential for increased risk of hypotension with concurrent use. Monitor blood pressure and adjust dose of antihypertensive agent as needed.

• magnesium supplement

  magnesium supplement, verapamil. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Calcium channel blockers may increase toxic effects of magnesium; magnesium may increase hypotensive effects of calcium channel blockers.

• maraviroc

  verapamil will increase the level or effect of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of maraviroc by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• marijuana

  marijuana will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• mefloquine

  mefloquine increases levels of verapamil by decreasing metabolism. Use Caution/Monitor. Risk of arrhythmia.
  
  verapamil will increase the level or effect of mefloquine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• mestranol

  verapamil will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• metformin

  verapamil decreases effects of metformin by Other (see comment). Use Caution/Monitor. Comment: Verapamil may inhibit hepatic uptake of metformin by OCT1 and/or other transporters.

• methadone

  verapamil will increase the level or effect of methadone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• methylphenidate

  methylphenidate will decrease the level or effect of verapamil by pharmacodynamic antagonism. Use Caution/Monitor. Methylphenidate may diminish antihypertensive effects. Monitor BP.

• methylprednisolone

  verapamil will increase the level or effect of methylprednisolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  methylprednisolone will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of methylprednisolone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• metoprolol

  metoprolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• metronidazole

  metronidazole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• mexiletine

  verapamil will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• miconazole vaginal

  miconazole vaginal will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• midazolam

  verapamil will increase the level or effect of midazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• mifepristone

  verapamil will increase the level or effect of mifepristone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  mifepristone will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• mipomersen

  mipomersen, verapamil. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Both drugs have potential to increase hepatic enzymes; monitor LFTs.

• mitotane

  mitotane decreases levels of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.

• moxisylyte

  moxisylyte and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• nadolol

  nadolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• nafcillin

  nafcillin will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nafcillin decreases levels of verapamil by increasing metabolism. Use Caution/Monitor.

• naldemedine

  verapamil increases levels of naldemedine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor naldemedine for potential adverse effects if coadministered with strong or moderate CYP3A4 inhibitors.
  
  verapamil increases levels of naldemedine by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor naldemedine for potential adverse effects if coadministered with P-gp inhibitors.

• nebivolol

  nebivolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• nelfinavir

  nelfinavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of nelfinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of nelfinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• neomycin PO

  verapamil will increase the level or effect of neomycin PO by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• nevirapine

  nevirapine will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• nicardipine

  verapamil will increase the level or effect of nicardipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nicardipine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• nifedipine

  nifedipine will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nifedipine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• nilotinib

  nilotinib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of nilotinib by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• nintedanib

  verapamil increases levels of nintedanib by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. If nintedanib adverse effects occur, management may require interruption, dose reduction, or discontinuation of therapy .

• nirmatrelvir/ritonavir

  nirmatrelvir/ritonavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor for increased bradycardia, hypotension, or dizziness. If needed, temporarily pause the antihypertensive drug.

• nisoldipine

  verapamil will increase the level or effect of nisoldipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nisoldipine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• nitroglycerin rectal

  nitroglycerin rectal, verapamil. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Marked orthostatic hypotension has been reported when calcium channel blockers and organic nitrates were used concomitantly. Observe for possible additive hypotensive effects during concomitant use. .

• nitroglycerin sublingual

  verapamil, nitroglycerin sublingual. Either increases toxicity of the other by additive vasodilation. Modify Therapy/Monitor Closely. Marked orthostatic hypotension reported with concomitant use.

• nitroprusside sodium

  verapamil increases effects of nitroprusside sodium by pharmacodynamic synergism. Use Caution/Monitor.

• olanzapine

  verapamil will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• oliceridine

  verapamil will increase the level or effect of oliceridine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If concomitant use is necessary, may require less frequent oliceridine dosing. Closely monitor for respiratory depression and sedation and titrate subsequent doses accordingly. If inhibitor is discontinued, consider increase oliceridine dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal.
  
  verapamil, oliceridine. Either increases effects of the other by serotonin levels. Modify Therapy/Monitor Closely.

• ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC)

  ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC) will increase the level or effect of verapamil by altering metabolism. Modify Therapy/Monitor Closely. Decrease dose of calcium channel blocker; clinical monitoring of patients is recommended for edema and/or signs and symptoms of hypotension. if such events occur, consider further dose reduction of calcium channel blocker or switching to alternative to calcium channel blocker m channel blocker dose if necessary

• oxcarbazepine

  oxcarbazepine will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• paclitaxel

  verapamil will increase the level or effect of paclitaxel by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• paclitaxel protein bound

  verapamil will increase the level or effect of paclitaxel protein bound by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• palbociclib

  verapamil will increase the level or effect of palbociclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• paliperidone

  verapamil will increase the level or effect of paliperidone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• paromomycin

  verapamil will increase the level or effect of paromomycin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• penbutolol

  penbutolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• pentobarbital

  pentobarbital will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• phenobarbital

  phenobarbital will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• phenoxybenzamine

  phenoxybenzamine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• phentolamine

  phentolamine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• phenytoin

  phenytoin will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• pindolol

  pindolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• ponatinib

  ponatinib increases levels of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• posaconazole

  posaconazole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of posaconazole by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• prazosin

  prazosin and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• prednisolone

  verapamil will increase the level or effect of prednisolone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• prednisone

  verapamil will increase the level or effect of prednisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  prednisone will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of prednisone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• primidone

  primidone will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• procainamide

  procainamide will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.

• propranolol

  propranolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• quetiapine

  verapamil will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• quinidine

  verapamil will increase the level or effect of quinidine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  quinidine will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.

• quinupristin/dalfopristin

  quinupristin/dalfopristin will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• repaglinide

  verapamil will increase the level or effect of repaglinide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ribociclib

  ribociclib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• rifapentine

  rifapentine will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• rifaximin

  verapamil increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• rimegepant

  verapamil will increase the level or effect of rimegepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Avoid repeating rimegepant dose within 48 hr if coadministered with a moderate CYP3A4 inhibitor.

• risperidone

  verapamil will increase the level or effect of risperidone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• ritonavir

  ritonavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of ritonavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• rivaroxaban

  verapamil increases levels of rivaroxaban by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Verapamil also inhibits P-gp activity, which can further increase rivaroxaban serum levels; since both pathways of rivaroxaban elimination are affected, patients with renal impairment receiving rivaroxaban with drugs that are combined P-gp and moderate CYP3A4 inhibitors may increase exposure compared to patients with normal renal function; monitor for bleeding.

• romidepsin

  verapamil will increase the level or effect of romidepsin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of romidepsin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• rucaparib

  rucaparib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.

• rufinamide

  rufinamide will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ruxolitinib

  verapamil will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ruxolitinib topical

  verapamil will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• saquinavir

  verapamil will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• sarecycline

  sarecycline will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor for toxicities of P-gp substrates that may require dosage reduction when coadministered with P-gp inhibitors.

• secobarbital

  secobarbital will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• sevelamer

  sevelamer decreases levels of verapamil by increasing elimination. Use Caution/Monitor.

• sildenafil

  verapamil will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• silodosin

  verapamil will increase the level or effect of silodosin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  silodosin and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• sodium sulfate/?magnesium sulfate/potassium chloride

  verapamil, sodium sulfate/?magnesium sulfate/potassium chloride. Either decreases toxicity of the other by unknown mechanism. Use Caution/Monitor. Monitor for hypotension or muscle weakness in patients receiving calcium channel blockers with elevated serum magnesium concentrations.

• sodium sulfate/potassium sulfate/magnesium sulfate

  verapamil, sodium sulfate/potassium sulfate/magnesium sulfate. Either decreases toxicity of the other by unknown mechanism. Use Caution/Monitor. Monitor for hypotension or muscle weakness in patients receiving calcium channel blockers with elevated serum magnesium concentrations.

• solifenacin

  verapamil will increase the level or effect of solifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• sonidegib

  verapamil will increase the level or effect of sonidegib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Avoid coadministration of sonidegib with moderate CYP3A4 inhibitors. If a moderate CYP3A inhibitor must be used, administer the moderate CYP3A inhibitor for <14 days and monitor closely for adverse reactions, particularly musculoskeletal adverse reactions.

• sotalol

  sotalol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• sparsentan

  verapamil will increase the level or effect of sparsentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment needed. Monitor blood pressure, serum potassium, edema, and kidney function regularly if sparsentan is coadministered with moderate CYP3A4 inhibitors.

• stiripentol

  stiripentol, verapamil. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.
  
  stiripentol will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Consider reducing the dose of P-glycoprotein (P-gp) substrates, if adverse reactions are experienced when administered concomitantly with stiripentol.

• streptomycin

  verapamil will increase the level or effect of streptomycin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• sufentanil

  verapamil will increase the level or effect of sufentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. There may be an increased incidence of bradycardia and hypotension during induction with sufentanil in patients receiving calcium channel blockers such as verapamil.

• sufentanil SL

  verapamil will increase the level or effect of sufentanil SL by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of sufentanil SL with any CYP3A4 inhibitor may increase sufentanil plasma concentration, and, thereby increase or prolonged adverse effects, including potentially fatal respiratory depression.

• sunitinib

  verapamil will increase the level or effect of sunitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• suvorexant

  verapamil will increase the level or effect of suvorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Decrease suvorexant starting dose to 5 mg HS if coadministered with moderate CYP3A4 inhibitors

• tacrolimus

  verapamil will increase the level or effect of tacrolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of tacrolimus by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• tadalafil

  verapamil will increase the level or effect of tadalafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Risk of hypotension.

• tamoxifen

  verapamil will increase the level or effect of tamoxifen by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inhibition decreases metabolism of tamoxifen to N-desmethyl tamoxifen (active metabolite with similar biologic activity)

• tapentadol

  verapamil and tapentadol both increase serotonin levels. Modify Therapy/Monitor Closely.

• tazemetostat

  tazemetostat will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tecovirimat

  tecovirimat will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.

• teniposide

  verapamil will increase the level or effect of teniposide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• tenofovir DF

  tenofovir DF increases levels of verapamil by decreasing renal clearance. Use Caution/Monitor. Potential for increased toxicity. .

• terazosin

  terazosin and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• tezacaftor

  verapamil will increase the level or effect of tezacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust tezacaftor dosage regimen if coadministered with a moderate CYP3A inhibitor.

• theophylline

  verapamil will increase the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• timolol

  timolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• tinidazole

  verapamil will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tipranavir

  verapamil will increase the level or effect of tipranavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  tipranavir, verapamil. Other (see comment). Use Caution/Monitor. Comment: Verapamil levels may incr or decr, due to contradictory effects of tipranavir on hepatic CYP3A4 and P glycoprotein.
  
  tipranavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tobramycin

  verapamil will increase the level or effect of tobramycin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• tofacitinib

  verapamil increases levels of tofacitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No specific dose adjustment recommended when tofacitinib coadministered with moderate CYP3A4 inhibitors; decrease tofacitinib dose if coadministered with both moderate CYP3A4 and potent CYP2C19 inhibitors .

• tolterodine

  verapamil will increase the level or effect of tolterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tolvaptan

  verapamil will increase the level or effect of tolvaptan by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Coadministration of moderate CYP 3A inhibitors, such as Verapamil with Tolvaptan should be avoided.

• topiramate

  topiramate will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• trabectedin

  verapamil will increase the level or effect of trabectedin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• trazodone

  verapamil will increase the level or effect of trazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• triamcinolone acetonide injectable suspension

  verapamil will increase the level or effect of triamcinolone acetonide injectable suspension by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• triazolam

  verapamil will increase the level or effect of triazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• trimagnesium citrate anhydrous

  trimagnesium citrate anhydrous, verapamil. Either increases effects of the other by sedation. Use Caution/Monitor. Possible additive effect of magnesium and calcium channel blockers on reduction of ionic calcium may increase risk of hypotension or muscle weakness.

• tucatinib

  tucatinib will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Consider reducing the dosage of P-gp substrates, where minimal concentration changes may lead to serious or life-threatening toxicities.

• vardenafil

  verapamil will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Vardenafil dose may need to be reduced if coadministered with moderate or strong CYP3A4 inhibitors

• vemurafenib

  verapamil increases levels of vemurafenib by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  vemurafenib increases levels of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• vinblastine

  verapamil will increase the level or effect of vinblastine by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• vincristine

  verapamil will increase the level or effect of vincristine by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• vincristine liposomal

  verapamil will increase the level or effect of vincristine liposomal by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• voclosporin

  verapamil will increase the level or effect of voclosporin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce voclosporin daily dosage to 15.8 mg PO in AM and 7.9 mg PO in PM.

• voriconazole

  voriconazole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Combo may increase risk of hypotension, bradycardia, AV block.
  
  voriconazole increases levels of verapamil by decreasing metabolism. Use Caution/Monitor.

• xipamide

  xipamide increases effects of verapamil by pharmacodynamic synergism. Use Caution/Monitor.

• zafirlukast

  zafirlukast will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• zanubrutinib

  verapamil will increase the level or effect of zanubrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce zanubrutinib (a CYP3A4 substrate) to 80 mg PO BID to when coadministered with a moderate CYP3A4 inhibitor. Interrupt dose as recommended for adverse reactions. After discontinuing the CYP3A4 inhibitor, resume previous dose of zanubrutinib.

Minor (118)

• acetazolamide

  acetazolamide will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• agrimony

  agrimony increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• alfuzosin

  verapamil will increase the level or effect of alfuzosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• alosetron

  verapamil will increase the level or effect of alosetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• alvimopan

  verapamil will increase the level or effect of alvimopan by P-glycoprotein (MDR1) efflux transporter. Minor/Significance Unknown.

• ambrisentan

  verapamil will increase the level or effect of ambrisentan by P-glycoprotein (MDR1) efflux transporter. Minor/Significance Unknown.

• amitriptyline

  verapamil will increase the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  verapamil increases levels of amitriptyline by decreasing metabolism. Minor/Significance Unknown.

• amoxapine

  verapamil increases levels of amoxapine by decreasing metabolism. Minor/Significance Unknown.

• anastrozole

  anastrozole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• antipyrine

  verapamil will increase the level or effect of antipyrine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• armodafinil

  verapamil will increase the level or effect of armodafinil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  verapamil will increase the level or effect of armodafinil by P-glycoprotein (MDR1) efflux transporter. Minor/Significance Unknown.

• asenapine

  verapamil will increase the level or effect of asenapine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• aspirin

  verapamil increases effects of aspirin by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• aspirin rectal

  verapamil increases effects of aspirin rectal by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• aspirin/citric acid/sodium bicarbonate

  verapamil increases effects of aspirin/citric acid/sodium bicarbonate by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• atracurium

  verapamil increases effects of atracurium by pharmacodynamic synergism. Minor/Significance Unknown. Ca Channel Blockers interfere w/Ach release from prejunctional axon.

• balsalazide

  verapamil increases effects of balsalazide by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• berotralstat

  verapamil increases levels of berotralstat by P-glycoprotein (MDR1) efflux transporter. Minor/Significance Unknown. Reduced berotralstat dose to 110 mg/day when coadministered with P-gp inhibitors.

• bosentan

  verapamil will increase the level or effect of bosentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• brimonidine

  brimonidine increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• caffeine

  verapamil will increase the level or effect of caffeine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• cevimeline

  verapamil will increase the level or effect of cevimeline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• choline magnesium trisalicylate

  verapamil increases effects of choline magnesium trisalicylate by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• cisatracurium

  verapamil increases effects of cisatracurium by pharmacodynamic synergism. Minor/Significance Unknown. Ca Channel Blockers interfere w/Ach release from prejunctional axon.

• clarithromycin

  verapamil will increase the level or effect of clarithromycin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• clomipramine

  verapamil will increase the level or effect of clomipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  verapamil increases levels of clomipramine by decreasing metabolism. Minor/Significance Unknown.

• colesevelam

  colesevelam decreases levels of verapamil by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown. (Sustained release form of verapamil).

• cornsilk

  cornsilk increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• cyclophosphamide

  cyclophosphamide will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• dapsone

  verapamil will increase the level or effect of dapsone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• darolutamide

  verapamil will increase the level or effect of darolutamide by Other (see comment). Minor/Significance Unknown. Darolutamide is a P-gp and CYP3A4 substrate. Closely monitor for increased adverse reactions and modify dose of darolutamide as needed when coadministered with drugs that are both P-gp and strong or moderate CYP3A4 inhibitors.

• desipramine

  verapamil increases levels of desipramine by decreasing metabolism. Minor/Significance Unknown.

• diflunisal

  verapamil increases effects of diflunisal by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• docetaxel

  verapamil will increase the level or effect of docetaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• donepezil

  verapamil will increase the level or effect of donepezil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• dosulepin

  verapamil increases levels of dosulepin by decreasing metabolism. Minor/Significance Unknown.

• doxepin

  verapamil increases levels of doxepin by decreasing metabolism. Minor/Significance Unknown.

• dutasteride

  verapamil will increase the level or effect of dutasteride by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• efavirenz

  verapamil will increase the level or effect of efavirenz by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• encainide

  verapamil increases levels of encainide by decreasing metabolism. Minor/Significance Unknown.

• estradiol vaginal

  verapamil will increase the level or effect of estradiol vaginal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• eucalyptus

  verapamil will increase the level or effect of eucalyptus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• fexofenadine

  verapamil will increase the level or effect of fexofenadine by P-glycoprotein (MDR1) efflux transporter. Minor/Significance Unknown.

• finasteride

  verapamil will increase the level or effect of finasteride by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• fo-ti

  fo-ti increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• forskolin

  forskolin increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• frovatriptan

  verapamil will increase the level or effect of frovatriptan by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• galantamine

  verapamil will increase the level or effect of galantamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• hydrochlorothiazide

  hydrochlorothiazide will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• imatinib

  verapamil will increase the level or effect of imatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• imipramine

  verapamil increases levels of imipramine by decreasing metabolism. Minor/Significance Unknown.

• isradipine

  verapamil will increase the level or effect of isradipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• itraconazole

  verapamil will increase the level or effect of itraconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ketoconazole

  verapamil will increase the level or effect of ketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• levoketoconazole

  verapamil will increase the level or effect of levoketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• lily of the valley

  verapamil, lily of the valley. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown.

• lithium

  verapamil increases toxicity of lithium by pharmacodynamic synergism. Minor/Significance Unknown. Increased risk of neurotoxicity.

• lofepramine

  verapamil increases levels of lofepramine by decreasing metabolism. Minor/Significance Unknown.

• loratadine

  verapamil will increase the level or effect of loratadine by P-glycoprotein (MDR1) efflux transporter. Minor/Significance Unknown.

• maitake

  maitake increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• maprotiline

  verapamil increases levels of maprotiline by decreasing metabolism. Minor/Significance Unknown.

• memantine

  memantine will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• mesalamine

  verapamil increases effects of mesalamine by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• metformin

  metformin will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• methyclothiazide

  methyclothiazide will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• metipranolol ophthalmic

  metipranolol ophthalmic increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• midodrine

  midodrine will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• montelukast

  verapamil will increase the level or effect of montelukast by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• nifedipine

  verapamil will increase the level or effect of nifedipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• nimodipine

  verapamil will increase the level or effect of nimodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• nitrendipine

  verapamil will increase the level or effect of nitrendipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• nortriptyline

  verapamil increases levels of nortriptyline by decreasing metabolism. Minor/Significance Unknown.

• octacosanol

  octacosanol increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• ofloxacin

  ofloxacin will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• onabotulinumtoxinA

  verapamil increases effects of onabotulinumtoxinA by pharmacodynamic synergism. Minor/Significance Unknown. Ca Channel Blockers interfere w/Ach release from prejunctional axon.

• ondansetron

  verapamil will increase the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
  
  verapamil will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• oxcarbazepine

  verapamil decreases levels of oxcarbazepine by increasing metabolism. Minor/Significance Unknown.

• oxybutynin

  verapamil will increase the level or effect of oxybutynin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• paclitaxel

  verapamil will increase the level or effect of paclitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• paclitaxel protein bound

  verapamil will increase the level or effect of paclitaxel protein bound by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• pancuronium

  verapamil increases effects of pancuronium by pharmacodynamic synergism. Minor/Significance Unknown. Ca Channel Blockers interfere w/Ach release from prejunctional axon.

• parecoxib

  verapamil will increase the level or effect of parecoxib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• pimozide

  verapamil will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• pioglitazone

  verapamil will increase the level or effect of pioglitazone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• porfimer

  verapamil decreases levels of porfimer by unspecified interaction mechanism. Minor/Significance Unknown.

• pramipexole

  pramipexole will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• propafenone

  verapamil will increase the level or effect of propafenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• protriptyline

  verapamil increases levels of protriptyline by decreasing metabolism. Minor/Significance Unknown.

• quinine

  verapamil will increase the level or effect of quinine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  quinine will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• ramelteon

  verapamil will increase the level or effect of ramelteon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• rapacuronium

  verapamil increases effects of rapacuronium by pharmacodynamic synergism. Minor/Significance Unknown. Ca Channel Blockers interfere w/Ach release from prejunctional axon.

• reishi

  reishi increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• riluzole

  verapamil will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• rocuronium

  verapamil increases effects of rocuronium by pharmacodynamic synergism. Minor/Significance Unknown. Ca Channel Blockers interfere w/Ach release from prejunctional axon.

• salicylates (non-asa)

  verapamil increases effects of salicylates (non-asa) by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• salsalate

  verapamil increases effects of salsalate by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• saxagliptin

  verapamil will increase the level or effect of saxagliptin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• shepherd's purse

  shepherd's purse, verapamil. Other (see comment). Minor/Significance Unknown. Comment: Theoretically, shepherd's purse may interfere with BP control.

• succinylcholine

  verapamil increases effects of succinylcholine by pharmacodynamic synergism. Minor/Significance Unknown. Ca Channel Blockers interfere w/Ach release from prejunctional axon.

• sulfamethoxazole

  sulfamethoxazole will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• sulfasalazine

  verapamil increases effects of sulfasalazine by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• tizanidine

  tizanidine increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypotension.

• trazodone

  verapamil increases levels of trazodone by decreasing metabolism. Minor/Significance Unknown.

• treprostinil

  treprostinil increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• triamterene

  triamterene will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• trimethoprim

  trimethoprim will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• trimipramine

  verapamil increases levels of trimipramine by decreasing metabolism. Minor/Significance Unknown.

• vecuronium

  verapamil increases effects of vecuronium by pharmacodynamic synergism. Minor/Significance Unknown. Ca Channel Blockers interfere w/Ach release from prejunctional axon.

• verteporfin

  verapamil increases levels of verteporfin by pharmacodynamic synergism. Minor/Significance Unknown.

• vinblastine

  verapamil will increase the level or effect of vinblastine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• vincristine

  verapamil will increase the level or effect of vincristine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• vincristine liposomal

  verapamil will increase the level or effect of vincristine liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• vinorelbine

  verapamil will increase the level or effect of vinorelbine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• willow bark

  verapamil increases effects of willow bark by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• zaleplon

  verapamil will increase the level or effect of zaleplon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ziprasidone

  verapamil will increase the level or effect of ziprasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• zolpidem

  verapamil will increase the level or effect of zolpidem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• zonisamide

  verapamil will increase the level or effect of zonisamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• abametapir

  Serious - Use Alternative (1)abametapir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP3A4 substrates. If not feasible, avoid use of abametapir.

• acalabrutinib

  Monitor Closely (1)verapamil will increase the level or effect of acalabrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Decrease acalabrutinib dose to 100 mg once daily if coadministered with a moderate CYP3A inhibitor.

• acebutolol

  Monitor Closely (1)acebutolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• acetazolamide

  Minor (1)acetazolamide will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• afatinib

  Serious - Use Alternative (1)verapamil increases levels of afatinib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. Reduce afatinib daily dose by 10 mg if not tolerated when coadministered with P-gp inhibitors.

• agrimony

  Minor (1)agrimony increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• aldesleukin

  Monitor Closely (1)aldesleukin increases effects of verapamil by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

• alfentanil

  Monitor Closely (1)verapamil will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. The risk of significant hypotension and/or bradycardia during therapy with alfentanil may be increased in patients receiving calcium-channel blockers.

• alfuzosin

  Monitor Closely (1)alfuzosin and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.Minor (1)verapamil will increase the level or effect of alfuzosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• aliskiren

  Monitor Closely (2)verapamil will increase the level or effect of aliskiren by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of aliskiren by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• almotriptan

  Monitor Closely (1)verapamil will increase the level or effect of almotriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• alosetron

  Serious - Use Alternative (1)verapamil will increase the level or effect of alosetron by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug.Minor (1)verapamil will increase the level or effect of alosetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• alprazolam

  Monitor Closely (1)verapamil will increase the level or effect of alprazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• alvimopan

  Minor (1)verapamil will increase the level or effect of alvimopan by P-glycoprotein (MDR1) efflux transporter. Minor/Significance Unknown.

• ambrisentan

  Minor (1)verapamil will increase the level or effect of ambrisentan by P-glycoprotein (MDR1) efflux transporter. Minor/Significance Unknown.

• amifostine

  Monitor Closely (1)amifostine, verapamil. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration with blood pressure lowering agents may increase the risk and severity of hypotension associated with amifostine. When amifostine is used at chemotherapeutic doses, withhold blood pressure lowering medications for 24 hr prior to amifostine; if blood pressure lowering medication cannot be withheld, do not administer amifostine.

• amikacin

  Monitor Closely (1)verapamil will increase the level or effect of amikacin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• amiodarone

  Monitor Closely (3)verapamil will increase the level or effect of amiodarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  amiodarone will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.
  
  amiodarone, verapamil. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of cardiotoxicity with bradycardia.

• amitriptyline

  Monitor Closely (1)verapamil will increase the level or effect of amitriptyline by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. The frequency and severity of amitriptyline adverse effects (sedation, anticholinergic effects and orthostatic hypotension) may be increased. Cardiac dysrhythmic effects may be additive. Minor (2)verapamil will increase the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  verapamil increases levels of amitriptyline by decreasing metabolism. Minor/Significance Unknown.

• amlodipine

  Monitor Closely (1)amlodipine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• amobarbital

  Monitor Closely (1)amobarbital will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• amoxapine

  Minor (1)verapamil increases levels of amoxapine by decreasing metabolism. Minor/Significance Unknown.

• anastrozole

  Minor (1)anastrozole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• antipyrine

  Minor (1)verapamil will increase the level or effect of antipyrine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• apalutamide

  Serious - Use Alternative (1)apalutamide will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.

• apixaban

  Monitor Closely (1)verapamil will increase the level or effect of apixaban by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Verapamil also inhibits P-gp activity, which can further increase apixaban serum levels; since both pathways of apixaban elimination are affected, patients with renal impairment receiving apixaban with drugs that are combined P-gp and moderate CYP3A4 inhibitors may increase exposure compared to patients with normal renal function; monitor for bleeding.

• aprepitant

  Monitor Closely (1)aprepitant will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• aripiprazole

  Monitor Closely (1)verapamil will increase the level or effect of aripiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• armodafinil

  Monitor Closely (1)armodafinil will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (2)verapamil will increase the level or effect of armodafinil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  verapamil will increase the level or effect of armodafinil by P-glycoprotein (MDR1) efflux transporter. Minor/Significance Unknown.

• artemether/lumefantrine

  Monitor Closely (1)verapamil will increase the level or effect of artemether/lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• asenapine

  Monitor Closely (1)asenapine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.Minor (1)verapamil will increase the level or effect of asenapine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• aspirin

  Minor (1)verapamil increases effects of aspirin by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• aspirin rectal

  Minor (1)verapamil increases effects of aspirin rectal by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• aspirin/citric acid/sodium bicarbonate

  Minor (1)verapamil increases effects of aspirin/citric acid/sodium bicarbonate by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• atazanavir

  Monitor Closely (2)atazanavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of atazanavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Caution advised, may increase risk of AV block

• atenolol

  Monitor Closely (1)atenolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)verapamil, atenolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• atogepant

  Monitor Closely (1)verapamil will increase the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• atorvastatin

  Monitor Closely (2)verapamil will increase the level or effect of atorvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of atorvastatin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• atracurium

  Minor (1)verapamil increases effects of atracurium by pharmacodynamic synergism. Minor/Significance Unknown. Ca Channel Blockers interfere w/Ach release from prejunctional axon.

• avanafil

  Monitor Closely (1)verapamil will increase the level or effect of avanafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inhibitors may reduce avanafil clearance increasing systemic exposure to avanafil; increased levels may result in increased associated adverse events; the maximum recommended dose of STENDRA is 50 mg, not to exceed once every 24 hours for patients taking concomitant moderate CYP3A4 inhibitors

• avapritinib

  Serious - Use Alternative (1)verapamil will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of avapritinib with strong CYP3A4 inhibitors.

• axitinib

  Serious - Use Alternative (1)verapamil increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with moderate CYP3A4 inhibitors, monitor closely and reduce dose if necessary .

• azithromycin

  Monitor Closely (1)azithromycin will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• balsalazide

  Minor (1)verapamil increases effects of balsalazide by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• bazedoxifene/conjugated estrogens

  Monitor Closely (2)verapamil will increase the level or effect of bazedoxifene/conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of bazedoxifene/conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• berotralstat

  Monitor Closely (1)berotralstat will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor or titrate P-gp substrate dose if coadministered.Minor (1)verapamil increases levels of berotralstat by P-glycoprotein (MDR1) efflux transporter. Minor/Significance Unknown. Reduced berotralstat dose to 110 mg/day when coadministered with P-gp inhibitors.

• betaxolol

  Monitor Closely (1)betaxolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)verapamil, betaxolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• betrixaban

  Monitor Closely (1)verapamil increases levels of betrixaban by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Decrease betrixaban dose to 80 mg PO once, then 40 mg PO qDay if coadministered with a P-gp inhibitor.

• bisoprolol

  Monitor Closely (1)bisoprolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)verapamil, bisoprolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• bortezomib

  Monitor Closely (1)verapamil will increase the level or effect of bortezomib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• bosentan

  Monitor Closely (1)bosentan will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)verapamil will increase the level or effect of bosentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• bosutinib

  Monitor Closely (1)bosutinib increases levels of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (2)verapamil increases levels of bosutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  verapamil increases levels of bosutinib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• bretylium

  Monitor Closely (1)verapamil, bretylium. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Each drug may cause hypotension.

• brexpiprazole

  Monitor Closely (1)verapamil will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP3A4 inhibitor PLUS a strong/moderate CYP2D6 inhibitor.

• brimonidine

  Minor (1)brimonidine increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• budesonide

  Monitor Closely (3)verapamil will increase the level or effect of budesonide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  budesonide will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of budesonide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• buprenorphine subdermal implant

  Monitor Closely (1)verapamil will increase the level or effect of buprenorphine subdermal implant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor patients already on buprenorphine subdermal implant who require newly-initiated treatment with CYP3A4 inhibitors for signs and symptoms of overmedication. If the dose of the concomitant CYP3A4 inhibitor cannot be reduced or discontinued, implant removal may be necessary and the patient should then be treated with a buprenorphine dosage form that permits dose adjustments. If a CYP3A4 inhibitor is discontinued in a patient who has been stabilized on buprenorphine, monitor the patient for withdrawal.

• buprenorphine, long-acting injection

  Monitor Closely (1)verapamil will increase the level or effect of buprenorphine, long-acting injection by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Patients who transfer to buprenorphine long-acting injection from transmucosal buprenorphine coadministered with CYP3A4 inhibitors should be monitored to ensure buprenorphine plasma levels are adequate. Within 2 weeks, if signs and symptoms of buprenorphine toxicity or overdose occur and the concomitant CYP3A4 inhibitor cannot be reduced or discontinued, transition the patient back to a buprenorphine formulation that permits dose adjustments.

• buspirone

  Monitor Closely (1)verapamil will increase the level or effect of buspirone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Consider lower buspirone doses.

• butabarbital

  Monitor Closely (1)butabarbital will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• butalbital

  Monitor Closely (1)butalbital will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cabazitaxel

  Monitor Closely (1)verapamil will increase the level or effect of cabazitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Caution should be exercised with concomitant use of moderate CYP3A4 inhibitors.

• cabozantinib

  Monitor Closely (1)verapamil will increase the level or effect of cabozantinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• caffeine

  Minor (1)verapamil will increase the level or effect of caffeine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• calcium acetate

  Monitor Closely (1)calcium acetate decreases effects of verapamil by pharmacodynamic antagonism. Use Caution/Monitor.

• calcium carbonate

  Monitor Closely (1)calcium carbonate decreases effects of verapamil by pharmacodynamic antagonism. Use Caution/Monitor.

• calcium chloride

  Monitor Closely (1)calcium chloride decreases effects of verapamil by pharmacodynamic antagonism. Use Caution/Monitor.

• calcium citrate

  Monitor Closely (1)calcium citrate decreases effects of verapamil by pharmacodynamic antagonism. Use Caution/Monitor.

• calcium gluconate

  Monitor Closely (1)calcium gluconate decreases effects of verapamil by pharmacodynamic antagonism. Use Caution/Monitor.

• cannabidiol

  Monitor Closely (1)verapamil will increase the level or effect of cannabidiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Consider reducing the cannabidiol dose when coadministered with a moderate CYP3A4 inhibitor.

• carbamazepine

  Monitor Closely (1)verapamil will increase the level or effect of carbamazepine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor plasma levels when used concomitantlySerious - Use Alternative (1)carbamazepine will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• carbidopa

  Monitor Closely (1)carbidopa increases effects of verapamil by pharmacodynamic synergism. Use Caution/Monitor. Therapy with carbidopa, given with or without levodopa or carbidopa-levodopa combination products, is started, dosage adjustment of the antihypertensive drug may be required.

• carvedilol

  Monitor Closely (1)carvedilol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• celiprolol

  Monitor Closely (1)celiprolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• ceritinib

  Monitor Closely (1)verapamil increases levels of ceritinib by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)ceritinib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• cevimeline

  Minor (1)verapamil will increase the level or effect of cevimeline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• chloramphenicol

  Monitor Closely (1)chloramphenicol will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

• choline magnesium trisalicylate

  Minor (1)verapamil increases effects of choline magnesium trisalicylate by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• cilostazol

  Monitor Closely (1)verapamil will increase the level or effect of cilostazol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Consider decreasing the cilostazol dose to 50 mg twice a day.

• cimetidine

  Monitor Closely (1)cimetidine will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.Serious - Use Alternative (1)cimetidine will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• cinacalcet

  Monitor Closely (1)verapamil will increase the level or effect of cinacalcet by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cisatracurium

  Minor (1)verapamil increases effects of cisatracurium by pharmacodynamic synergism. Minor/Significance Unknown. Ca Channel Blockers interfere w/Ach release from prejunctional axon.

• clarithromycin

  Monitor Closely (1)clarithromycin will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increased effect of calcium channel blockers may lead to hypotension, edema, decreased HR, and acute kidney injury due to reduced renal blood flowMinor (1)verapamil will increase the level or effect of clarithromycin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• clevidipine

  Monitor Closely (1)clevidipine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• clomipramine

  Monitor Closely (1)verapamil will increase the level or effect of clomipramine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.Minor (2)verapamil will increase the level or effect of clomipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  verapamil increases levels of clomipramine by decreasing metabolism. Minor/Significance Unknown.

• clonidine

  Monitor Closely (2)clonidine, verapamil. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Sinus bradycardia resulting in hospitalization and pacemaker insertion has been reported in association with the use of clonidine concurrently with verapamil. Monitor heart rate in patients receiving concomitant verapamil and clonidine.
  
  verapamil, clonidine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Sinus bradycardia resulting in hospitalization and pacemaker insertion has been reported in association with the use of clonidine concurrently with verapamil. Monitor heart rate in patients receiving concomitant verapamil and clonidine.

• clopidogrel

  Monitor Closely (1)verapamil will decrease the level or effect of clopidogrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Inhibition of CYP3A4 will reduce clopidogrel bioactivation

• clozapine

  Monitor Closely (2)verapamil will increase the level or effect of clozapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of clozapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cobicistat

  Monitor Closely (1)cobicistat will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cobimetinib

  Serious - Use Alternative (1)verapamil will increase the level or effect of cobimetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If concurrent short term (14 days or less) use of moderate CYP3A inhibitors is unavoidable for patients who are taking cobimetinib 60 mg, reduce the cobimetinib dose to 20 mg. After discontinuation of a moderate CYP3A inhibitor, resume cobimetinib 60 mg. Use an alternative to a moderate CYP3A inhibitor in patients who are taking a reduced dose of cobimetinib (40 or 20 mg daily).

• colchicine

  Serious - Use Alternative (1)verapamil will increase the level or effect of colchicine by Other (see comment). Avoid or Use Alternate Drug. Colchicine is a P-gp and CYP3A4 substrate. Avoid use with drugs that are both P-gp and strong CYP3A4 inhibitors. If coadministration is necessary, decrease colchicine dose or frequency as recommended in prescribing information. Use of any colchicine product in conjunction with strong CYP3A4 inhibitors is contraindicated in patients with renal or hepatic impairment.

• colesevelam

  Minor (1)colesevelam decreases levels of verapamil by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown. (Sustained release form of verapamil).

• conivaptan

  Monitor Closely (1)conivaptan will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• conjugated estrogens

  Monitor Closely (2)verapamil will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• conjugated estrogens, vaginal

  Monitor Closely (2)verapamil will increase the level or effect of conjugated estrogens, vaginal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of conjugated estrogens, vaginal by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• cornsilk

  Minor (1)cornsilk increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• cortisone

  Monitor Closely (3)verapamil will increase the level or effect of cortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  cortisone will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of cortisone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• crizotinib

  Monitor Closely (3)crizotinib increases levels of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.
  
  crizotinib increases levels of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  verapamil increases levels of crizotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Caution should be exercised with concomitant use of moderate CYP3A inhibitors. .

• crofelemer

  Monitor Closely (1)crofelemer increases levels of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.

• cyclobenzaprine

  Serious - Use Alternative (1)verapamil and cyclobenzaprine both increase serotonin levels. Avoid or Use Alternate Drug.

• cyclophosphamide

  Minor (1)cyclophosphamide will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• cyclosporine

  Monitor Closely (1)verapamil, cyclosporine. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Verapamil and cyclosporine may inhibit CYP3A4 metabolism. Coadministration of verapamil and cyclosporine may increase plasma concentrations of either drugs.

• dabigatran

  Monitor Closely (1)verapamil will increase the level or effect of dabigatran by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Atrial fibrillation: Avoid coadministering dabigatran with P-gp inhibitors if CrCl <30 mL/min. DVT/PE treatment: Avoid coadministering dabigatran with P-gp inhibitors if CrCl <50 mL/min

• dabrafenib

  Monitor Closely (1)dabrafenib will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

• dantrolene

  Contraindicated (1)dantrolene, verapamil. Either increases toxicity of the other by Mechanism: pharmacodynamic synergism. Contraindicated. Rare incidence of cardiovascular collapse and marked hyperkalemia observed when coadministered; may be higher risk with nondihydropyridine calcium channel blockers.

• dapsone

  Minor (1)verapamil will increase the level or effect of dapsone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• daridorexant

  Monitor Closely (1)verapamil will increase the level or effect of daridorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Daridorexant dose should not exceed 25 mg per night when coadministered with moderate CYP3A4 inhibitors.

• darifenacin

  Monitor Closely (2)darifenacin will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• darolutamide

  Minor (1)verapamil will increase the level or effect of darolutamide by Other (see comment). Minor/Significance Unknown. Darolutamide is a P-gp and CYP3A4 substrate. Closely monitor for increased adverse reactions and modify dose of darolutamide as needed when coadministered with drugs that are both P-gp and strong or moderate CYP3A4 inhibitors.

• darunavir

  Monitor Closely (1)darunavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• dasatinib

  Monitor Closely (1)dasatinib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• daunorubicin

  Monitor Closely (1)verapamil will increase the level or effect of daunorubicin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• deferasirox

  Monitor Closely (1)deferasirox will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• deflazacort

  Monitor Closely (2)verapamil will increase the level or effect of deflazacort by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  verapamil will increase the level or effect of deflazacort by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Decrease deflazacort dose to one-third of the recommended dose if coadministered with moderate or strong CYP3A4 inhibitors.

• desipramine

  Minor (1)verapamil increases levels of desipramine by decreasing metabolism. Minor/Significance Unknown.

• dexamethasone

  Monitor Closely (3)verapamil will increase the level or effect of dexamethasone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  dexamethasone will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of dexamethasone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• DHEA, herbal

  Monitor Closely (1)DHEA, herbal will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• diazepam

  Monitor Closely (1)verapamil will increase the level or effect of diazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• diazepam intranasal

  Monitor Closely (1)verapamil will increase the level or effect of diazepam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong or moderate CYP3A4 inhibitors may decrease rate of diazepam elimination, thereby increasing adverse reactions to diazepam.

• dienogest/estradiol valerate

  Monitor Closely (1)verapamil will increase the level or effect of dienogest/estradiol valerate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor for potential adverse effects such as nausea, irregular uterine bleeding, breast tenderness and headache.

• diflunisal

  Minor (1)verapamil increases effects of diflunisal by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• digoxin

  Monitor Closely (2)verapamil will increase the level or effect of digoxin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Toxicity characterized by gastrointestinal and neuropsychiatric symptoms, and cardiac arrhythmias may result.
  
  digoxin will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.Serious - Use Alternative (1)verapamil increases levels of digoxin by decreasing renal clearance. Avoid or Use Alternate Drug.

• dihydroergotamine

  Serious - Use Alternative (1)verapamil will increase the level or effect of dihydroergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• dihydroergotamine intranasal

  Serious - Use Alternative (1)verapamil will increase the level or effect of dihydroergotamine intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• diltiazem

  Monitor Closely (3)diltiazem will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of diltiazem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. These agents have additive hypotensive effects that may be beneficial however, it is important to monitor patients carefully.
  
  diltiazem and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor. Antihypertensives may enhance the hypotensive effects of other antihypertensive agents when used together.

• disopyramide

  Monitor Closely (1)verapamil will increase the level or effect of disopyramide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Avoid disopyramide administration within 48 hours before or 24 hours after verapamil administration.

• docetaxel

  Monitor Closely (1)verapamil will increase the level or effect of docetaxel by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Minor (1)verapamil will increase the level or effect of docetaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• dofetilide

  Monitor Closely (1)dofetilide will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.

• donepezil

  Minor (1)verapamil will increase the level or effect of donepezil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• dosulepin

  Minor (1)verapamil increases levels of dosulepin by decreasing metabolism. Minor/Significance Unknown.

• doxazosin

  Monitor Closely (1)doxazosin and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• doxepin

  Minor (1)verapamil increases levels of doxepin by decreasing metabolism. Minor/Significance Unknown.

• doxorubicin

  Monitor Closely (2)verapamil will increase the level or effect of doxorubicin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil increases levels of doxorubicin by decreasing metabolism. Use Caution/Monitor. Coadministration of doxorubicin and calcium channel blockers may increase the risk of doxorubicin cardiotoxicity. .

• doxorubicin liposomal

  Monitor Closely (2)verapamil will increase the level or effect of doxorubicin liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil increases toxicity of doxorubicin liposomal by decreasing metabolism. Use Caution/Monitor. Coadministration of doxorubicin and calcium channel blockers may increase the risk of doxorubicin cardiotoxicity. .

• dronedarone

  Monitor Closely (1)dronedarone will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)verapamil will increase the level or effect of dronedarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• duloxetine

  Serious - Use Alternative (1)verapamil will increase the level or effect of duloxetine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug.

• dutasteride

  Minor (1)verapamil will increase the level or effect of dutasteride by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• duvelisib

  Monitor Closely (2)verapamil will increase the level or effect of duvelisib by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  duvelisib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with duvelisib increases AUC of a sensitive CYP3A4 substrate which may increase the risk of toxicities of these drugs. Consider reducing the dose of the sensitive CYP3A4 substrate and monitor for signs of toxicities of the coadministered sensitive CYP3A substrate.

• edoxaban

  Serious - Use Alternative (1)verapamil will increase the level or effect of edoxaban by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. Dose adjustment may be required with strong P-gp inhibitors. DVT/PE treatment: Decrease dose to 30 mg PO once daily. NVAF: No dose reduction recommended

• efavirenz

  Monitor Closely (1)efavirenz will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)verapamil will increase the level or effect of efavirenz by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• elacestrant

  Serious - Use Alternative (1)verapamil will increase the level or effect of elacestrant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• elagolix

  Monitor Closely (2)elagolix will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  elagolix decreases levels of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.

• eletriptan

  Monitor Closely (1)verapamil will increase the level or effect of eletriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• eliglustat

  Monitor Closely (1)eliglustat increases levels of verapamil by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the P-gp substrate and titrate to clinical effect.Serious - Use Alternative (1)verapamil increases levels of eliglustat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Moderate CYP3A4 inhibitors are not recommended with eliglustat poor or intermediate metabolizers; reduce eliglustat dose from 84 mg BID to 84 mg once daily in extensive metabolizers .

• elvitegravir/cobicistat/emtricitabine/tenofovir DF

  Monitor Closely (1)elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.

• encainide

  Minor (1)verapamil increases levels of encainide by decreasing metabolism. Minor/Significance Unknown.

• encorafenib

  Monitor Closely (1)encorafenib, verapamil. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.Serious - Use Alternative (1)verapamil will increase the level or effect of encorafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If concomitant use of a moderate CYP3A4 inhibitor is unavoidable, reduce encorafenib dose to one-half of the dose (eg, reduce from 450 mg/day to 225 mg/day). After discontinuing the inhibitor for 3-5 elimination half-lives, resume previous encorafenib dose.

• entrectinib

  Serious - Use Alternative (1)verapamil will increase the level or effect of entrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of moderate CYP3A4 inhibitors with entrectinib, a CYP3A4 substrate. If coadministration unavoidable, reduce dose to 200 mg/day for patients aged 12 y or older with BSA >1.50m2. Resume previous entrectinib dose after discontinuing moderate CYP3A inhibitor for 3-5 elimination half-lives.

• enzalutamide

  Monitor Closely (1)enzalutamide will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• eplerenone

  Monitor Closely (1)verapamil will increase the level or effect of eplerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Plasma concentrations and pharmacologic or toxic effects of eplerenone may be increased by verapamil.

• erdafitinib

  Serious - Use Alternative (1)erdafitinib will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

• ergotamine

  Serious - Use Alternative (1)verapamil will increase the level or effect of ergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• erlotinib

  Monitor Closely (1)verapamil will increase the level or effect of erlotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• erythromycin base

  Serious - Use Alternative (2)verapamil will increase the level or effect of erythromycin base by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.
  
  erythromycin base will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin ethylsuccinate

  Serious - Use Alternative (2)verapamil will increase the level or effect of erythromycin ethylsuccinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.
  
  erythromycin ethylsuccinate will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin lactobionate

  Serious - Use Alternative (2)verapamil will increase the level or effect of erythromycin lactobionate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.
  
  erythromycin lactobionate will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin stearate

  Serious - Use Alternative (2)verapamil will increase the level or effect of erythromycin stearate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.
  
  erythromycin stearate will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• eslicarbazepine acetate

  Monitor Closely (2)eslicarbazepine acetate will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil decreases levels of eslicarbazepine acetate by increasing metabolism. Modify Therapy/Monitor Closely.

• esmolol

  Monitor Closely (1)esmolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)verapamil, esmolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• estradiol

  Monitor Closely (2)verapamil will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• estradiol vaginal

  Minor (1)verapamil will increase the level or effect of estradiol vaginal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• estrogens conjugated synthetic

  Monitor Closely (2)verapamil will increase the level or effect of estrogens conjugated synthetic by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of estrogens conjugated synthetic by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• estrogens esterified

  Monitor Closely (1)verapamil will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• estropipate

  Monitor Closely (2)verapamil will increase the level or effect of estropipate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of estropipate by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• ethanol

  Monitor Closely (1)verapamil increases levels of ethanol by decreasing metabolism. Use Caution/Monitor.

• etonogestrel

  Monitor Closely (1)verapamil will increase the level or effect of etonogestrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• etoposide

  Monitor Closely (1)verapamil will increase the level or effect of etoposide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• etravirine

  Monitor Closely (2)verapamil will increase the level or effect of etravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  etravirine will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• eucalyptus

  Minor (1)verapamil will increase the level or effect of eucalyptus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• everolimus

  Monitor Closely (1)everolimus will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Everolimus prescribing information lists indication-specific dosing recommendations.Serious - Use Alternative (3)verapamil will increase the level or effect of everolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Concomitant use of a moderate 3A4 inhibitor such as verapamil may significantly increase the plasma concentrations of everolimus following oral administration.
  
  verapamil will increase the level or effect of everolimus by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. Everolimus prescribing information lists indication-specific dosing recommendations.
  
  verapamil, everolimus. Either increases levels of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: With concomitant use of mTOR inhibitors, consider appropriate dose reductions of both medications.

• fedratinib

  Monitor Closely (1)fedratinib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• felodipine

  Monitor Closely (2)verapamil will increase the level or effect of felodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  felodipine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• fentanyl

  Serious - Use Alternative (1)verapamil will increase the level or effect of fentanyl by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

• fentanyl intranasal

  Serious - Use Alternative (1)verapamil will increase the level or effect of fentanyl intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

• fentanyl transdermal

  Serious - Use Alternative (1)verapamil will increase the level or effect of fentanyl transdermal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

• fentanyl transmucosal

  Serious - Use Alternative (1)verapamil will increase the level or effect of fentanyl transmucosal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

• fesoterodine

  Monitor Closely (1)verapamil will increase the level or effect of fesoterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fexinidazole

  Serious - Use Alternative (1)fexinidazole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.

• fexofenadine

  Minor (1)verapamil will increase the level or effect of fexofenadine by P-glycoprotein (MDR1) efflux transporter. Minor/Significance Unknown.

• fezolinetant

  Contraindicated (1)verapamil will increase the level or effect of fezolinetant by affecting hepatic enzyme CYP1A2 metabolism. Contraindicated. Fezolinetant AUC and peak plasma concentration are increased if coadministered with drugs that are weak, moderate, or strong CYP1A2 inhibitors

• finasteride

  Minor (1)verapamil will increase the level or effect of finasteride by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• finerenone

  Monitor Closely (1)verapamil will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor serum potassium during initiation and dosage adjustment of either finererone or moderate CYP3A4 inhibitors. Adjust finererone dosage as needed.

• flibanserin

  Contraindicated (1)verapamil will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of flibanserin with moderate or strong CYP3A4 inhibitors is contraindicated. Severe hypotension or syncope can occur.

• fluconazole

  Monitor Closely (1)fluconazole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fludrocortisone

  Monitor Closely (3)verapamil will increase the level or effect of fludrocortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  fludrocortisone will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of fludrocortisone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• fluvoxamine

  Monitor Closely (1)fluvoxamine will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fo-ti

  Minor (1)fo-ti increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• forskolin

  Minor (1)forskolin increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• fosamprenavir

  Monitor Closely (1)fosamprenavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fosaprepitant

  Monitor Closely (1)fosaprepitant will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fosphenytoin

  Monitor Closely (1)fosphenytoin will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fostamatinib

  Monitor Closely (1)fostamatinib will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Concomitant use of fostamatinib may increase concentrations of P-gp substrates. Monitor for toxicities of the P-gp substrate drug that may require dosage reduction when given concurrently with fostamatinib.

• frovatriptan

  Minor (1)verapamil will increase the level or effect of frovatriptan by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• galantamine

  Minor (1)verapamil will increase the level or effect of galantamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• gentamicin

  Monitor Closely (1)verapamil will increase the level or effect of gentamicin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• glecaprevir/pibrentasvir

  Monitor Closely (2)verapamil will increase the level or effect of glecaprevir/pibrentasvir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  glecaprevir/pibrentasvir will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• grapefruit

  Monitor Closely (1)grapefruit will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• green tea

  Monitor Closely (1)verapamil increases levels of green tea by decreasing elimination. Use Caution/Monitor. (Caffeine). Verapamil reduces clearance of caffeine and increases serum caffeine concentrations, presumably via inhibition of hepatic metabolism. May advise patients to limit or minimize the intake of caffeinated products to minimize caffeine-related side effects.

• griseofulvin

  Monitor Closely (1)griseofulvin will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• guanfacine

  Monitor Closely (1)verapamil will increase the level or effect of guanfacine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong or moderate CYP3A4 inhibitors significantly increase guanfacine plasma concentrations. FDA-approved labeling for extended-release (ER) guanfacine recommends that, if coadministered, the guanfacine dosage should be decreased to half of the recommended dose. Specific recommendations for immediate-release (IR) guanfacine are not available.

• hawthorn

  Monitor Closely (1)hawthorn increases effects of verapamil by pharmacodynamic synergism. Use Caution/Monitor.

• hydrochlorothiazide

  Minor (1)hydrochlorothiazide will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• hydrocortisone

  Monitor Closely (3)verapamil will increase the level or effect of hydrocortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  hydrocortisone will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of hydrocortisone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• hydroxyprogesterone caproate (DSC)

  Monitor Closely (1)verapamil will increase the level or effect of hydroxyprogesterone caproate (DSC) by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ibrutinib

  Serious - Use Alternative (1)verapamil increases levels of ibrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of ibrutinib and strong CYP3A4 inhibitors. If a strong CYP3A4 inhibitor must be used short-term (eg, anti-infectives for =7 days), interrupt ibrutinib therapy until strong CYP3A4 inhibitor is discontinued.

• idelalisib

  Serious - Use Alternative (1)idelalisib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates

• ifosfamide

  Monitor Closely (1)verapamil decreases effects of ifosfamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Use of a CYP3A4 inhibitor may decrease metabolism of ifosfamide, potentially reducing ifosfamide therapeutic effects.

• iloperidone

  Monitor Closely (2)verapamil will increase the level or effect of iloperidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  iloperidone increases levels of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.

• imatinib

  Monitor Closely (1)verapamil will increase the level or effect of imatinib by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Minor (1)verapamil will increase the level or effect of imatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• imipramine

  Monitor Closely (2)verapamil will increase the level or effect of imipramine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of imipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. TCA level may be increased.Minor (1)verapamil increases levels of imipramine by decreasing metabolism. Minor/Significance Unknown.

• indacaterol, inhaled

  Monitor Closely (1)verapamil increases levels of indacaterol, inhaled by Other (see comment). Use Caution/Monitor. Comment: Data suggests that systemic clearance is influenced by modulation of both P-gp and CYP3A4 activities. No dose adjustment is warranted at the 75 mcg dose.

• indinavir

  Monitor Closely (3)indinavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of indinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of indinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• infigratinib

  Serious - Use Alternative (1)verapamil will increase the level or effect of infigratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• irinotecan

  Monitor Closely (1)verapamil will increase the level or effect of irinotecan by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)verapamil will increase the level or effect of irinotecan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• irinotecan liposomal

  Monitor Closely (1)verapamil will increase the level or effect of irinotecan liposomal by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)verapamil will increase the level or effect of irinotecan liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• isavuconazonium sulfate

  Monitor Closely (1)verapamil will increase the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• isoniazid

  Monitor Closely (1)isoniazid will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• isradipine

  Monitor Closely (1)isradipine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.Minor (1)verapamil will increase the level or effect of isradipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• istradefylline

  Monitor Closely (2)istradefylline will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.
  
  istradefylline will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of P-gp substrates in clinical trials. Consider dose reduction of sensitive P-gp substrates.

• itraconazole

  Monitor Closely (2)verapamil will increase the level or effect of itraconazole by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  itraconazole will increase the level or effect of verapamil by Other (see comment). Modify Therapy/Monitor Closely. CCBs elicit negative inotropic effects which may be additive to those of itraconazole; additionally, itraconazole can inhibit the metabolism of calcium channel blockers. Monitor for adverse reactions. Concomitant drug dose reduction may be necessary. Serious - Use Alternative (1)itraconazole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Observe the patient for development of toxicity associated with verapamil (peripheral edema, dizziness, hypotension, flushing, headache). Consider reducing the dose of verapamil or withdrawing one of the agents.Minor (1)verapamil will increase the level or effect of itraconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ivabradine

  Monitor Closely (1)verapamil, ivabradine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Most patients receiving ivabradine will also be treated with a beta-blocker. The risk of bradycardia increases with coadministration of drugs that slow heart rate (eg, digoxin, amiodarone, beta-blockers). Monitor heart rate in patients taking ivabradine with other negative chronotropes.Serious - Use Alternative (1)verapamil will increase the level or effect of ivabradine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of ivabradine with moderate CYP3A4 inhibitors.

• ivacaftor

  Monitor Closely (2)ivacaftor increases levels of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Ivacaftor and its M1 metabolite has the potential to inhibit P-gp; may significantly increase systemic exposure to sensitive P-gp substrates with a narrow therapeutic index.
  
  verapamil will increase the level or effect of ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce ivacaftor dose if coadministered with moderate CYP3A4 inhibitors. See specific ivacaftor-containing product for precise dosage modification.

• ivermectin

  Monitor Closely (1)verapamil will increase the level or effect of ivermectin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• ivosidenib

  Monitor Closely (1)verapamil will increase the level or effect of ivosidenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration with moderate CYP3A4 inhibitors may increase ivosidenib plasma concentrations, thus increasing the risk of QTc prolongation. Monitor for increased risk of QTc interval prolongation.Serious - Use Alternative (1)ivosidenib will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternative therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.

• ixabepilone

  Monitor Closely (1)verapamil will increase the level or effect of ixabepilone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ketoconazole

  Monitor Closely (1)ketoconazole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)verapamil will increase the level or effect of ketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• labetalol

  Monitor Closely (1)labetalol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• lapatinib

  Monitor Closely (2)lapatinib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of lapatinib by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• larotrectinib

  Serious - Use Alternative (1)verapamil will increase the level or effect of larotrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• lasmiditan

  Serious - Use Alternative (1)lasmiditan increases levels of verapamil by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• lefamulin

  Monitor Closely (1)verapamil will increase the level or effect of lefamulin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor for adverse effects if lefamulin is coadministered with moderate CYP3A inhibitors.

• lemborexant

  Serious - Use Alternative (1)verapamil will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of lemborexant with moderate or strong CYP3A inhibitors.

• lenacapavir

  Monitor Closely (1)lenacapavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lencapavir may increase CYP3A4 substrates initiated within 9 months after last SC dose of lenacapavir, which may increase potential risk of adverse reactions of CYP3A4 substrates.

• levamlodipine

  Monitor Closely (1)verapamil will increase the level or effect of levamlodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with moderate and strong CYP3A inhibitors results in increased systemic exposure to amlodipine and may require dose reduction. Monitor for symptoms of hypotension and edema when amlodipine is coadministered with CYP3A inhibitors to determine the need for dose adjustment.

• levobunolol

  Serious - Use Alternative (1)verapamil, levobunolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• levodopa

  Monitor Closely (1)levodopa increases effects of verapamil by pharmacodynamic synergism. Use Caution/Monitor. Consider decreasing dosage of antihypertensive agent.

• levoketoconazole

  Monitor Closely (1)levoketoconazole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)verapamil will increase the level or effect of levoketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• lidocaine

  Monitor Closely (1)verapamil will increase the level or effect of lidocaine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• lily of the valley

  Minor (1)verapamil, lily of the valley. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown.

• lithium

  Minor (1)verapamil increases toxicity of lithium by pharmacodynamic synergism. Minor/Significance Unknown. Increased risk of neurotoxicity.

• lofepramine

  Minor (1)verapamil increases levels of lofepramine by decreasing metabolism. Minor/Significance Unknown.

• lofexidine

  Serious - Use Alternative (1)lofexidine, verapamil. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid coadministration with other drugs that decrease pulse or blood pressure to mitigate risk of excessive bradycardia and hypotension.

• lomitapide

  Contraindicated (1)verapamil increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Increases lomitapide levels several folds.Monitor Closely (1)lomitapide increases levels of verapamil by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Consider reducing dose when used concomitantly with lomitapide.

• lonafarnib

  Contraindicated (1)verapamil will increase the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Lonafarnib is a sensitive CYP3A4 substrate. Coadministration with strong or moderate CYP3A4 inhibitors is contraindicated.

• loperamide

  Monitor Closely (1)verapamil will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• lopinavir

  Monitor Closely (1)verapamil will increase the level or effect of lopinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)lopinavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• loratadine

  Monitor Closely (1)verapamil will increase the level or effect of loratadine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)verapamil will increase the level or effect of loratadine by P-glycoprotein (MDR1) efflux transporter. Minor/Significance Unknown.

• lorlatinib

  Monitor Closely (1)lorlatinib will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• lovastatin

  Monitor Closely (1)verapamil will increase the level or effect of lovastatin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Avoid concomitant use of verapamil and lovastatin if possible. If used together, use lower doses of lovastatin and monitor for lovastatin toxicity (myositis, rhabdomyolysis).Serious - Use Alternative (1)verapamil will increase the level or effect of lovastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Do not exceed 20 mg of lovastatin

• lumateperone

  Monitor Closely (1)verapamil will increase the level or effect of lumateperone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce lumateperone dose to 21 mg/day if coadministered with moderate CYP3A4 inhibitors.

• lumefantrine

  Monitor Closely (1)verapamil will increase the level or effect of lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• lurasidone

  Monitor Closely (2)verapamil increases levels of lurasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Manufacturer recommends decreasing starting dose of lurasidone to 20 mg/day and maximum daily dose of lurasidone 80 mg when coadministered with moderate CYP3A4 inhibitors. Concurrent use may increase risk of lurasidone-related adverse reactions.
  
  lurasidone increases effects of verapamil by Other (see comment). Use Caution/Monitor. Comment: Potential for increased risk of hypotension with concurrent use. Monitor blood pressure and adjust dose of antihypertensive agent as needed.

• lurbinectedin

  Serious - Use Alternative (1)verapamil will increase the level or effect of lurbinectedin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• magnesium supplement

  Monitor Closely (1)magnesium supplement, verapamil. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Calcium channel blockers may increase toxic effects of magnesium; magnesium may increase hypotensive effects of calcium channel blockers.

• maitake

  Minor (1)maitake increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• maprotiline

  Minor (1)verapamil increases levels of maprotiline by decreasing metabolism. Minor/Significance Unknown.

• maraviroc

  Monitor Closely (2)verapamil will increase the level or effect of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of maraviroc by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• marijuana

  Monitor Closely (1)marijuana will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• mavacamten

  Serious - Use Alternative (1)verapamil, mavacamten. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Expect additive negative inotropic effects of mavacamten and other drugs that reduce cardiac contractility.

• mefloquine

  Monitor Closely (2)mefloquine increases levels of verapamil by decreasing metabolism. Use Caution/Monitor. Risk of arrhythmia.
  
  verapamil will increase the level or effect of mefloquine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• memantine

  Minor (1)memantine will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• mesalamine

  Minor (1)verapamil increases effects of mesalamine by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• mestranol

  Monitor Closely (2)verapamil will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• metformin

  Monitor Closely (1)verapamil decreases effects of metformin by Other (see comment). Use Caution/Monitor. Comment: Verapamil may inhibit hepatic uptake of metformin by OCT1 and/or other transporters.Minor (1)metformin will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• methadone

  Monitor Closely (1)verapamil will increase the level or effect of methadone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• methyclothiazide

  Minor (1)methyclothiazide will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• methylphenidate

  Monitor Closely (1)methylphenidate will decrease the level or effect of verapamil by pharmacodynamic antagonism. Use Caution/Monitor. Methylphenidate may diminish antihypertensive effects. Monitor BP.

• methylprednisolone

  Monitor Closely (3)verapamil will increase the level or effect of methylprednisolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  methylprednisolone will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of methylprednisolone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• metipranolol ophthalmic

  Minor (1)metipranolol ophthalmic increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• metoprolol

  Monitor Closely (1)metoprolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)verapamil, metoprolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• metronidazole

  Monitor Closely (1)metronidazole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• mexiletine

  Monitor Closely (1)verapamil will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• miconazole vaginal

  Monitor Closely (1)miconazole vaginal will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• midazolam

  Monitor Closely (1)verapamil will increase the level or effect of midazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• midazolam intranasal

  Serious - Use Alternative (1)verapamil will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of moderate CYP3A4 inhibitors with midazolam intranasal causes higher midazolam systemic exposure, which may prolong sedation.

• midodrine

  Minor (1)midodrine will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• mifepristone

  Monitor Closely (2)verapamil will increase the level or effect of mifepristone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  mifepristone will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• mipomersen

  Monitor Closely (1)mipomersen, verapamil. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Both drugs have potential to increase hepatic enzymes; monitor LFTs.

• mitotane

  Monitor Closely (1)mitotane decreases levels of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.

• mobocertinib

  Serious - Use Alternative (1)verapamil will increase the level or effect of mobocertinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If use of moderate CYP3A4 inhibitor unavoidable, reduce mobocertinib dose by ~50% (eg, 160 to 80 mg); closely monitor QTc interval.

• montelukast

  Minor (1)verapamil will increase the level or effect of montelukast by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• moxisylyte

  Monitor Closely (1)moxisylyte and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• nadolol

  Monitor Closely (1)nadolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)verapamil, nadolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• nafcillin

  Monitor Closely (2)nafcillin will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nafcillin decreases levels of verapamil by increasing metabolism. Use Caution/Monitor.

• naldemedine

  Monitor Closely (2)verapamil increases levels of naldemedine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor naldemedine for potential adverse effects if coadministered with strong or moderate CYP3A4 inhibitors.
  
  verapamil increases levels of naldemedine by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor naldemedine for potential adverse effects if coadministered with P-gp inhibitors.

• naloxegol

  Serious - Use Alternative (1)verapamil will increase the level or effect of naloxegol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministation of naloxegol with moderate CYP3A4 inhibitors is unavoidable, reduce naloxegol dose to 12.5 mg qDay

• nebivolol

  Monitor Closely (1)nebivolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)verapamil, nebivolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• nefazodone

  Serious - Use Alternative (1)nefazodone will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• nelfinavir

  Monitor Closely (3)nelfinavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of nelfinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of nelfinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• neomycin PO

  Monitor Closely (1)verapamil will increase the level or effect of neomycin PO by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• neratinib

  Serious - Use Alternative (1)verapamil will increase the level or effect of neratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of neratinib with strong/moderate CYP3A4 inhibitors.

• nevirapine

  Monitor Closely (1)nevirapine will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• nicardipine

  Monitor Closely (2)verapamil will increase the level or effect of nicardipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nicardipine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• nifedipine

  Monitor Closely (2)nifedipine will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nifedipine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.Minor (1)verapamil will increase the level or effect of nifedipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• nilotinib

  Monitor Closely (2)nilotinib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of nilotinib by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• nimodipine

  Minor (1)verapamil will increase the level or effect of nimodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• nintedanib

  Monitor Closely (1)verapamil increases levels of nintedanib by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. If nintedanib adverse effects occur, management may require interruption, dose reduction, or discontinuation of therapy .

• nirmatrelvir/ritonavir

  Monitor Closely (1)nirmatrelvir/ritonavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor for increased bradycardia, hypotension, or dizziness. If needed, temporarily pause the antihypertensive drug.

• nisoldipine

  Monitor Closely (2)verapamil will increase the level or effect of nisoldipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nisoldipine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• nitrendipine

  Minor (1)verapamil will increase the level or effect of nitrendipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• nitroglycerin rectal

  Monitor Closely (1)nitroglycerin rectal, verapamil. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Marked orthostatic hypotension has been reported when calcium channel blockers and organic nitrates were used concomitantly. Observe for possible additive hypotensive effects during concomitant use. .

• nitroglycerin sublingual

  Monitor Closely (1)verapamil, nitroglycerin sublingual. Either increases toxicity of the other by additive vasodilation. Modify Therapy/Monitor Closely. Marked orthostatic hypotension reported with concomitant use.

• nitroprusside sodium

  Monitor Closely (1)verapamil increases effects of nitroprusside sodium by pharmacodynamic synergism. Use Caution/Monitor.

• nortriptyline

  Minor (1)verapamil increases levels of nortriptyline by decreasing metabolism. Minor/Significance Unknown.

• octacosanol

  Minor (1)octacosanol increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• ofloxacin

  Minor (1)ofloxacin will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• olanzapine

  Monitor Closely (1)verapamil will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• olaparib

  Serious - Use Alternative (1)verapamil will increase the level or effect of olaparib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with moderate CYP3A inhibitors cannot be avoided, reduce olaparib dose to 200 mg (capsule) or 150 mg (tablet) PO BID. Do not substitute tablets with capsules.

• oliceridine

  Monitor Closely (2)verapamil will increase the level or effect of oliceridine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If concomitant use is necessary, may require less frequent oliceridine dosing. Closely monitor for respiratory depression and sedation and titrate subsequent doses accordingly. If inhibitor is discontinued, consider increase oliceridine dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal.
  
  verapamil, oliceridine. Either increases effects of the other by serotonin levels. Modify Therapy/Monitor Closely.

• omaveloxolone

  Serious - Use Alternative (1)verapamil will increase the level or effect of omaveloxolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unavoidable, reduce omaveloxolone dose to 100 mg/day. Closely monitor for adverse effects. If adverse effects emerge, further reduce to 50 mg/day.

• ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC)

  Monitor Closely (1)ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC) will increase the level or effect of verapamil by altering metabolism. Modify Therapy/Monitor Closely. Decrease dose of calcium channel blocker; clinical monitoring of patients is recommended for edema and/or signs and symptoms of hypotension. if such events occur, consider further dose reduction of calcium channel blocker or switching to alternative to calcium channel blocker m channel blocker dose if necessary

• onabotulinumtoxinA

  Minor (1)verapamil increases effects of onabotulinumtoxinA by pharmacodynamic synergism. Minor/Significance Unknown. Ca Channel Blockers interfere w/Ach release from prejunctional axon.

• ondansetron

  Minor (2)verapamil will increase the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
  
  verapamil will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• oxcarbazepine

  Monitor Closely (1)oxcarbazepine will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)verapamil decreases levels of oxcarbazepine by increasing metabolism. Minor/Significance Unknown.

• oxybutynin

  Minor (1)verapamil will increase the level or effect of oxybutynin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ozanimod

  Serious - Use Alternative (1)ozanimod increases toxicity of verapamil by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Avoid or Use Alternate Drug. Because the active metabolite of ozanimod inhibits MAO-B in vitro, there is a potential for serious adverse reactions, including hypertensive crisis. Therefore, coadministration of ozanimod with drugs that can increase norepinephrine or serotonin is not recommended. Monitor for hypertension with concomitant use.

• paclitaxel

  Monitor Closely (1)verapamil will increase the level or effect of paclitaxel by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Minor (1)verapamil will increase the level or effect of paclitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• paclitaxel protein bound

  Monitor Closely (1)verapamil will increase the level or effect of paclitaxel protein bound by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Minor (1)verapamil will increase the level or effect of paclitaxel protein bound by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• pacritinib

  Serious - Use Alternative (1)verapamil will increase the level or effect of pacritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• palbociclib

  Monitor Closely (1)verapamil will increase the level or effect of palbociclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• paliperidone

  Monitor Closely (1)verapamil will increase the level or effect of paliperidone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• pancuronium

  Minor (1)verapamil increases effects of pancuronium by pharmacodynamic synergism. Minor/Significance Unknown. Ca Channel Blockers interfere w/Ach release from prejunctional axon.

• parecoxib

  Minor (1)verapamil will increase the level or effect of parecoxib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• paromomycin

  Monitor Closely (1)verapamil will increase the level or effect of paromomycin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• pazopanib

  Serious - Use Alternative (1)verapamil will increase the level or effect of pazopanib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of pazopanib with strong CYP3A4 inhibitors if possible; if must coadminister, decrease pazopanib dose to 400 mg/day

• pemigatinib

  Serious - Use Alternative (1)verapamil will increase the level or effect of pemigatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong or moderate CYP3A4 inhibitors is unavoidable, reduce pemigatinib dose (refer to drug monograph dosage modifications). After discontinuing the CYP3A4 inhibitor for 3 elimination half-lives, may resume previous pemigatinib dose.

• penbutolol

  Monitor Closely (1)penbutolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• pentobarbital

  Monitor Closely (1)pentobarbital will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• pexidartinib

  Serious - Use Alternative (1)verapamil will increase the level or effect of pexidartinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong or moderate CYP3A4 inhibitors is unavoidable, reduce pexidartinib dose (refer to drug monograph dosage modifications). After discontinuing the CYP3A4 inhibitor for 3 elimination half-lives, may resume previous pexidartinib dose.

• phenobarbital

  Monitor Closely (1)phenobarbital will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• phenoxybenzamine

  Monitor Closely (1)phenoxybenzamine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• phentolamine

  Monitor Closely (1)phentolamine and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• phenytoin

  Monitor Closely (1)phenytoin will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• pimozide

  Contraindicated (1)verapamil increases levels of pimozide by decreasing metabolism. Contraindicated. Risk of QT interval prolongation.Minor (1)verapamil will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• pindolol

  Monitor Closely (1)pindolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• pioglitazone

  Minor (1)verapamil will increase the level or effect of pioglitazone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• pomalidomide

  Serious - Use Alternative (1)verapamil increases levels of pomalidomide by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• ponatinib

  Monitor Closely (1)ponatinib increases levels of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• ponesimod

  Serious - Use Alternative (1)ponesimod, verapamil. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Consult cardiologist if considering treatment. Generally, should not be initiated in patients who are concurrently taking QT prolonging drugs with known arrhythmogenic properties, such as HR-lowering calcium channel blockers (eg, verapamil, diltiazem).

• porfimer

  Minor (1)verapamil decreases levels of porfimer by unspecified interaction mechanism. Minor/Significance Unknown.

• posaconazole

  Monitor Closely (2)posaconazole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of posaconazole by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• pramipexole

  Minor (1)pramipexole will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• prazosin

  Monitor Closely (1)prazosin and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• prednisolone

  Monitor Closely (1)verapamil will increase the level or effect of prednisolone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• prednisone

  Monitor Closely (3)verapamil will increase the level or effect of prednisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  prednisone will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of prednisone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• primidone

  Monitor Closely (1)primidone will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• procainamide

  Monitor Closely (1)procainamide will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.

• propafenone

  Minor (1)verapamil will increase the level or effect of propafenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• propranolol

  Monitor Closely (1)propranolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)verapamil, propranolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• protriptyline

  Minor (1)verapamil increases levels of protriptyline by decreasing metabolism. Minor/Significance Unknown.

• quetiapine

  Monitor Closely (1)verapamil will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• quinidine

  Monitor Closely (2)verapamil will increase the level or effect of quinidine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  quinidine will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.

• quinine

  Minor (2)verapamil will increase the level or effect of quinine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  quinine will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• quinupristin/dalfopristin

  Monitor Closely (1)quinupristin/dalfopristin will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ramelteon

  Minor (1)verapamil will increase the level or effect of ramelteon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ranolazine

  Serious - Use Alternative (1)verapamil will increase the level or effect of ranolazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• rapacuronium

  Minor (1)verapamil increases effects of rapacuronium by pharmacodynamic synergism. Minor/Significance Unknown. Ca Channel Blockers interfere w/Ach release from prejunctional axon.

• reishi

  Minor (1)reishi increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• repaglinide

  Monitor Closely (1)verapamil will increase the level or effect of repaglinide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ribociclib

  Monitor Closely (1)ribociclib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• rifabutin

  Serious - Use Alternative (1)rifabutin will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• rifampin

  Serious - Use Alternative (1)rifampin will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• rifapentine

  Monitor Closely (1)rifapentine will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• rifaximin

  Monitor Closely (1)verapamil increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• riluzole

  Minor (1)verapamil will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• rimegepant

  Monitor Closely (1)verapamil will increase the level or effect of rimegepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Avoid repeating rimegepant dose within 48 hr if coadministered with a moderate CYP3A4 inhibitor.Serious - Use Alternative (1)verapamil will increase the level or effect of rimegepant by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• riociguat

  Serious - Use Alternative (1)verapamil will increase the level or effect of riociguat by decreasing metabolism. Avoid or Use Alternate Drug. Coadministration of riociguat (substrate of CYP isoenzymes 1A1, 2C8, 3A, 2J2) with strong CYP inhibitors may require a decreased initial dose of 0.5 mg PO TID; monitor for signs of hypotension and reduce dose if needed

• risperidone

  Monitor Closely (1)verapamil will increase the level or effect of risperidone by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• ritonavir

  Monitor Closely (2)ritonavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of ritonavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• rivaroxaban

  Monitor Closely (1)verapamil increases levels of rivaroxaban by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Verapamil also inhibits P-gp activity, which can further increase rivaroxaban serum levels; since both pathways of rivaroxaban elimination are affected, patients with renal impairment receiving rivaroxaban with drugs that are combined P-gp and moderate CYP3A4 inhibitors may increase exposure compared to patients with normal renal function; monitor for bleeding.

• rocuronium

  Minor (1)verapamil increases effects of rocuronium by pharmacodynamic synergism. Minor/Significance Unknown. Ca Channel Blockers interfere w/Ach release from prejunctional axon.

• romidepsin

  Monitor Closely (2)verapamil will increase the level or effect of romidepsin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  verapamil will increase the level or effect of romidepsin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• rucaparib

  Monitor Closely (1)rucaparib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.

• rufinamide

  Monitor Closely (1)rufinamide will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ruxolitinib

  Monitor Closely (1)verapamil will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ruxolitinib topical

  Monitor Closely (1)verapamil will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• salicylates (non-asa)

  Minor (1)verapamil increases effects of salicylates (non-asa) by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• salsalate

  Minor (1)verapamil increases effects of salsalate by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• saquinavir

  Monitor Closely (2)verapamil will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• sarecycline

  Monitor Closely (1)sarecycline will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor for toxicities of P-gp substrates that may require dosage reduction when coadministered with P-gp inhibitors.

• saxagliptin

  Minor (1)verapamil will increase the level or effect of saxagliptin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• secobarbital

  Monitor Closely (1)secobarbital will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• selumetinib

  Serious - Use Alternative (1)verapamil will increase the level or effect of selumetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong or moderate CYP3A4 inhibitors cannot be avoided, reduce selumetinib dosage (refer to selumetinib monograph for further information). After discontinuation of the strong or moderate CYP3A4 inhibitor for 3 elimination half-lives, resume selumetinib dose that was taken before initiating the inhibitor.

• sevelamer

  Monitor Closely (1)sevelamer decreases levels of verapamil by increasing elimination. Use Caution/Monitor.

• shepherd's purse

  Minor (1)shepherd's purse, verapamil. Other (see comment). Minor/Significance Unknown. Comment: Theoretically, shepherd's purse may interfere with BP control.

• sildenafil

  Monitor Closely (1)verapamil will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• silodosin

  Monitor Closely (2)verapamil will increase the level or effect of silodosin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  silodosin and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.Serious - Use Alternative (1)verapamil will increase the level or effect of silodosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• simvastatin

  Serious - Use Alternative (1)verapamil will increase the level or effect of simvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Do not exceed simvastatin 10 mg daily when given concurrently. Potential for increased risk of myopathy/rhabdomyolysis.

• siponimod

  Serious - Use Alternative (2)siponimod, verapamil. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.
  
  verapamil will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• sirolimus

  Serious - Use Alternative (3)verapamil will increase the level or effect of sirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  verapamil will increase the level or effect of sirolimus by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.
  
  verapamil, sirolimus. Either increases levels of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: With concomitant use of mTOR inhibitors, consider appropriate dose reductions of both medications.

• sodium sulfate/?magnesium sulfate/potassium chloride

  Monitor Closely (1)verapamil, sodium sulfate/?magnesium sulfate/potassium chloride. Either decreases toxicity of the other by unknown mechanism. Use Caution/Monitor. Monitor for hypotension or muscle weakness in patients receiving calcium channel blockers with elevated serum magnesium concentrations.

• sodium sulfate/potassium sulfate/magnesium sulfate

  Monitor Closely (1)verapamil, sodium sulfate/potassium sulfate/magnesium sulfate. Either decreases toxicity of the other by unknown mechanism. Use Caution/Monitor. Monitor for hypotension or muscle weakness in patients receiving calcium channel blockers with elevated serum magnesium concentrations.

• solifenacin

  Monitor Closely (1)verapamil will increase the level or effect of solifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• sonidegib

  Monitor Closely (1)verapamil will increase the level or effect of sonidegib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Avoid coadministration of sonidegib with moderate CYP3A4 inhibitors. If a moderate CYP3A inhibitor must be used, administer the moderate CYP3A inhibitor for <14 days and monitor closely for adverse reactions, particularly musculoskeletal adverse reactions.

• sotalol

  Monitor Closely (1)sotalol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)verapamil, sotalol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• sotorasib

  Serious - Use Alternative (1)sotorasib will decrease the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If use is unavoidable, refer to the prescribing information of the P-gp substrate for dosage modifications.

• sparsentan

  Monitor Closely (1)verapamil will increase the level or effect of sparsentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment needed. Monitor blood pressure, serum potassium, edema, and kidney function regularly if sparsentan is coadministered with moderate CYP3A4 inhibitors.

• St John's Wort

  Serious - Use Alternative (1)St John's Wort will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• stiripentol

  Monitor Closely (2)stiripentol, verapamil. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.
  
  stiripentol will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Consider reducing the dose of P-glycoprotein (P-gp) substrates, if adverse reactions are experienced when administered concomitantly with stiripentol.

• streptomycin

  Monitor Closely (1)verapamil will increase the level or effect of streptomycin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• succinylcholine

  Minor (1)verapamil increases effects of succinylcholine by pharmacodynamic synergism. Minor/Significance Unknown. Ca Channel Blockers interfere w/Ach release from prejunctional axon.

• sufentanil

  Monitor Closely (1)verapamil will increase the level or effect of sufentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. There may be an increased incidence of bradycardia and hypotension during induction with sufentanil in patients receiving calcium channel blockers such as verapamil.

• sufentanil SL

  Monitor Closely (1)verapamil will increase the level or effect of sufentanil SL by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of sufentanil SL with any CYP3A4 inhibitor may increase sufentanil plasma concentration, and, thereby increase or prolonged adverse effects, including potentially fatal respiratory depression.

• sulbactam/durlobactam

  Serious - Use Alternative (1)verapamil will increase the level or effect of sulbactam/durlobactam by Other (see comment). Avoid or Use Alternate Drug. Sulbactam is predicted to have active secretion by OATP1 as a significant portion of total clearance; therefore, inhibition of OAT1 may increase sulbactam plasma concentrations

• sulfamethoxazole

  Minor (1)sulfamethoxazole will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• sulfasalazine

  Minor (1)verapamil increases effects of sulfasalazine by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• sunitinib

  Monitor Closely (1)verapamil will increase the level or effect of sunitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• suvorexant

  Monitor Closely (1)verapamil will increase the level or effect of suvorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Decrease suvorexant starting dose to 5 mg HS if coadministered with moderate CYP3A4 inhibitors

• tacrolimus

  Monitor Closely (2)verapamil will increase the level or effect of tacrolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of tacrolimus by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• tadalafil

  Monitor Closely (1)verapamil will increase the level or effect of tadalafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Risk of hypotension.

• talazoparib

  Serious - Use Alternative (1)verapamil will increase the level or effect of talazoparib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration with certain P-gp inhibitors (ie, amiodarone, carvedilol, clarithromycin, itraconazole, verapamil) cannot be avoided, reduce talazoparib dose to 0.75 mg qDay. Once P-gp inhibitors are discontinued, increase talazoparib dose (after 3-5 half-lives of the inhibitor) to dose used prior to initiating the P-gp inhibitor(s).

• tamoxifen

  Monitor Closely (1)verapamil will increase the level or effect of tamoxifen by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inhibition decreases metabolism of tamoxifen to N-desmethyl tamoxifen (active metabolite with similar biologic activity)

• tapentadol

  Monitor Closely (1)verapamil and tapentadol both increase serotonin levels. Modify Therapy/Monitor Closely.

• tazemetostat

  Monitor Closely (1)tazemetostat will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)verapamil will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of tazemetostat with moderate CYP3A4 inhibitors. If coadministration is unavoidable, reduce tazemetostat current dose (see drug monograph Dosage Modifications).

• tecovirimat

  Monitor Closely (1)tecovirimat will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.

• temsirolimus

  Serious - Use Alternative (2)verapamil, temsirolimus. Either increases levels of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: With concomitant use of mTOR inhibitors, consider appropriate dose reductions of both medications.
  
  verapamil will increase the level or effect of temsirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• teniposide

  Monitor Closely (1)verapamil will increase the level or effect of teniposide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• tenofovir DF

  Monitor Closely (1)tenofovir DF increases levels of verapamil by decreasing renal clearance. Use Caution/Monitor. Potential for increased toxicity. .

• tepotinib

  Serious - Use Alternative (1)tepotinib will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If concomitant use unavoidable, reduce the P-gp substrate dosage if recommended in its approved product labeling.

• terazosin

  Monitor Closely (1)terazosin and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.

• tezacaftor

  Monitor Closely (1)verapamil will increase the level or effect of tezacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust tezacaftor dosage regimen if coadministered with a moderate CYP3A inhibitor.

• theophylline

  Monitor Closely (2)verapamil will increase the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• timolol

  Monitor Closely (1)timolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)verapamil, timolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• tinidazole

  Monitor Closely (1)verapamil will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tipranavir

  Monitor Closely (3)verapamil will increase the level or effect of tipranavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  tipranavir, verapamil. Other (see comment). Use Caution/Monitor. Comment: Verapamil levels may incr or decr, due to contradictory effects of tipranavir on hepatic CYP3A4 and P glycoprotein.
  
  tipranavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tizanidine

  Serious - Use Alternative (1)verapamil will increase the level or effect of tizanidine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug.Minor (1)tizanidine increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypotension.

• tobramycin

  Monitor Closely (1)verapamil will increase the level or effect of tobramycin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• tofacitinib

  Monitor Closely (1)verapamil increases levels of tofacitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No specific dose adjustment recommended when tofacitinib coadministered with moderate CYP3A4 inhibitors; decrease tofacitinib dose if coadministered with both moderate CYP3A4 and potent CYP2C19 inhibitors .

• tolterodine

  Monitor Closely (1)verapamil will increase the level or effect of tolterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tolvaptan

  Monitor Closely (1)verapamil will increase the level or effect of tolvaptan by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Coadministration of moderate CYP 3A inhibitors, such as Verapamil with Tolvaptan should be avoided.Serious - Use Alternative (1)verapamil will increase the level or effect of tolvaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• topiramate

  Monitor Closely (1)topiramate will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• topotecan

  Serious - Use Alternative (1)verapamil will increase the level or effect of topotecan by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. Product labeling for PO topotecan recommends avoiding concomitant use of P-gp inhibitors; the interaction with IV topotecan may be less severe but is still likely of clinical significance

• trabectedin

  Monitor Closely (1)verapamil will increase the level or effect of trabectedin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• trazodone

  Monitor Closely (1)verapamil will increase the level or effect of trazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)verapamil increases levels of trazodone by decreasing metabolism. Minor/Significance Unknown.

• treprostinil

  Minor (1)treprostinil increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• triamcinolone acetonide injectable suspension

  Monitor Closely (1)verapamil will increase the level or effect of triamcinolone acetonide injectable suspension by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• triamterene

  Minor (1)triamterene will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• triazolam

  Monitor Closely (1)verapamil will increase the level or effect of triazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• trimagnesium citrate anhydrous

  Monitor Closely (1)trimagnesium citrate anhydrous, verapamil. Either increases effects of the other by sedation. Use Caution/Monitor. Possible additive effect of magnesium and calcium channel blockers on reduction of ionic calcium may increase risk of hypotension or muscle weakness.

• trimethoprim

  Minor (1)trimethoprim will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• trimipramine

  Minor (1)verapamil increases levels of trimipramine by decreasing metabolism. Minor/Significance Unknown.

• tucatinib

  Monitor Closely (1)tucatinib will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Consider reducing the dosage of P-gp substrates, where minimal concentration changes may lead to serious or life-threatening toxicities.Serious - Use Alternative (1)tucatinib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.

• vardenafil

  Monitor Closely (1)verapamil will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Vardenafil dose may need to be reduced if coadministered with moderate or strong CYP3A4 inhibitors

• vecuronium

  Minor (1)verapamil increases effects of vecuronium by pharmacodynamic synergism. Minor/Significance Unknown. Ca Channel Blockers interfere w/Ach release from prejunctional axon.

• vemurafenib

  Monitor Closely (2)verapamil increases levels of vemurafenib by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  vemurafenib increases levels of verapamil by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• venetoclax

  Serious - Use Alternative (2)verapamil will increase the level or effect of venetoclax by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If a moderate CYP3A inhibitor must be used, reduce the venetoclax dose by at least 50%. Monitor more closely for signs of venetoclax toxicities.
  
  verapamil will increase the level or effect of venetoclax by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If a P-gp inhibitor must be used, reduce the venetoclax dose by at least 50%. Monitor more closely for signs of venetoclax toxicities.

• verteporfin

  Minor (1)verapamil increases levels of verteporfin by pharmacodynamic synergism. Minor/Significance Unknown.

• vilazodone

  Serious - Use Alternative (1)verapamil increases levels of vilazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If intolerable adverse effects occur when coadministered with moderate CYP3A4 inhibitors, reduce daily dose to 20 mg.

• vinblastine

  Monitor Closely (1)verapamil will increase the level or effect of vinblastine by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Minor (1)verapamil will increase the level or effect of vinblastine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• vincristine

  Monitor Closely (1)verapamil will increase the level or effect of vincristine by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Minor (1)verapamil will increase the level or effect of vincristine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• vincristine liposomal

  Monitor Closely (1)verapamil will increase the level or effect of vincristine liposomal by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Minor (1)verapamil will increase the level or effect of vincristine liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• vinorelbine

  Minor (1)verapamil will increase the level or effect of vinorelbine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• voclosporin

  Monitor Closely (1)verapamil will increase the level or effect of voclosporin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce voclosporin daily dosage to 15.8 mg PO in AM and 7.9 mg PO in PM.

• voriconazole

  Monitor Closely (2)voriconazole will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Combo may increase risk of hypotension, bradycardia, AV block.
  
  voriconazole increases levels of verapamil by decreasing metabolism. Use Caution/Monitor.

• vortioxetine

  Serious - Use Alternative (1)verapamil, vortioxetine. Either increases effects of the other by serotonin levels. Avoid or Use Alternate Drug.

• voxelotor

  Serious - Use Alternative (1)voxelotor will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.

• willow bark

  Minor (1)verapamil increases effects of willow bark by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• xipamide

  Monitor Closely (1)xipamide increases effects of verapamil by pharmacodynamic synergism. Use Caution/Monitor.

• zafirlukast

  Monitor Closely (1)zafirlukast will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• zaleplon

  Minor (1)verapamil will increase the level or effect of zaleplon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• zanubrutinib

  Monitor Closely (1)verapamil will increase the level or effect of zanubrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce zanubrutinib (a CYP3A4 substrate) to 80 mg PO BID to when coadministered with a moderate CYP3A4 inhibitor. Interrupt dose as recommended for adverse reactions. After discontinuing the CYP3A4 inhibitor, resume previous dose of zanubrutinib.

• ziprasidone

  Minor (1)verapamil will increase the level or effect of ziprasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• zolpidem

  Minor (1)verapamil will increase the level or effect of zolpidem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• zonisamide

  Minor (1)verapamil will increase the level or effect of zonisamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.