butabarbital (Rx)

Sedative or Hypnotic

Hypnotic: 50-100 mg qHS

Daytime sedation: 15-30 mg q6-8hr

Preoperative sedation: 50-100 mg 60-90 minutes before surgery

Renal Impairment

Reduce dosage if use is necessary

Hepatic Impairment

Reduce dosage if use is necessary

Sedation

Preoperative sedation: 2-6 mg/kg; not to exceed 100 mg/dose  

Use with caution; may administer a dose at the low end of the range

Contraindicated (6)

• calcium/magnesium/potassium/sodium oxybates

  butabarbital, calcium/magnesium/potassium/sodium oxybates. Either increases effects of the other by pharmacodynamic synergism. Contraindicated. Coadministration with alcohol or sedative hypnotics are contraindicated because of additive CNS depression.

• doravirine

  butabarbital will decrease the level or effect of doravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of doravirine with a strong CYP3A inducer may decrease doravirine plasma concentrations and/or effects. Potential for loss of virologic response and possible resistance to doravirine.

• fostemsavir

  butabarbital will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.

• lonafarnib

  butabarbital will decrease 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 inducers is contraindicated.

• lorlatinib

  butabarbital will decrease the level or effect of lorlatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of lorlatinib with strong CYP3A inducers is contraindicated. Discontinue the strong CYP3A inducer for 3 plasma half-lives before initiating lorlatinib.

• sodium oxybate

  butabarbital, sodium oxybate. Either increases effects of the other by pharmacodynamic synergism. Contraindicated. Coadministration with alcohol or sedative hypnotics are contraindicated because of additive CNS depression.

Serious - Use Alternative (89)

• abemaciclib

  butabarbital will decrease the level or effect of abemaciclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of abemaciclib with strong CYP3A4 inducers reduces plasma concentration of abemaciclib and its metabolites.

• acalabrutinib

  butabarbital will decrease the level or effect of acalabrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of acalabrutinib with strong CYP3A inducers. If a strong CYP3A inducer must be used, increase acalabrutinib dose to 200 mg twice daily.

• alosetron

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

• alpelisib

  butabarbital will decrease the level or effect of alpelisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of alpelisib (CYP3A4 substrate) with strong CYP3A4 inducers.

• antithrombin alfa

  butabarbital decreases effects of antithrombin alfa by increasing metabolism. Avoid or Use Alternate Drug.

• antithrombin III

  butabarbital decreases effects of antithrombin III by increasing metabolism. Avoid or Use Alternate Drug.

• argatroban

  butabarbital decreases effects of argatroban by increasing metabolism. Avoid or Use Alternate Drug.

• avapritinib

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

• bemiparin

  butabarbital decreases effects of bemiparin by increasing metabolism. Avoid or Use Alternate Drug.

• benzhydrocodone/acetaminophen

  benzhydrocodone/acetaminophen, butabarbital. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• bivalirudin

  butabarbital decreases effects of bivalirudin by increasing metabolism. Avoid or Use Alternate Drug.

• brigatinib

  butabarbital will decrease the level or effect of brigatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration with strong CYP3A4 inducers may decrease brigatinib efficacy.

• copanlisib

  butabarbital will decrease the level or effect of copanlisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of copanlisib with strong CYP3A4 inducers.

• dalteparin

  butabarbital decreases effects of dalteparin by increasing metabolism. Avoid or Use Alternate Drug.

• deflazacort

  butabarbital will decrease the level or effect of deflazacort by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of deflazacort with moderate or strong CYP3A4 inducers.

• dihydroergotamine

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

• dihydroergotamine intranasal

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

• dronedarone

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

• duloxetine

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

• duvelisib

  butabarbital will decrease the level or effect of duvelisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration with a strong CYP3A inducer decreases duvelisib area under the curve (AUC), which may reduce duvelisib efficacy.

• enoxaparin

  butabarbital decreases effects of enoxaparin by increasing metabolism. Avoid or Use Alternate Drug.

• erdafitinib

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

• ergotamine

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

• erythromycin base

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

• erythromycin ethylsuccinate

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

• erythromycin lactobionate

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

• erythromycin stearate

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

• ethinylestradiol

  butabarbital will decrease the level or effect of ethinylestradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. The efficacy of hormonal contraceptives may be reduced. Use of a nonhormonal contraceptive is recommended.

• everolimus

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

• fedratinib

  butabarbital will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• fentanyl

  fentanyl, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl intranasal

  fentanyl intranasal, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl transdermal

  fentanyl transdermal, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl transmucosal

  fentanyl transmucosal, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fexinidazole

  butabarbital will increase the level or effect of fexinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. CYP450 inducers may significantly increase plasma concentrations of fexinidazole?s active metabolites: fexinidazole sulfoxide (M1) and fexinidazole sulfone (M2). M2 plasma concentrations associated with increased QT prolongation risks.

• finerenone

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

• fondaparinux

  butabarbital decreases effects of fondaparinux by increasing metabolism. Avoid or Use Alternate Drug.

• fostamatinib

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

• glasdegib

  butabarbital will decrease the level or effect of glasdegib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of glasdegib with strong CYP3A inducers.

• heparin

  butabarbital decreases effects of heparin by increasing metabolism. Avoid or Use Alternate Drug.

• hydrocodone

  hydrocodone, butabarbital. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• infigratinib

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

• isocarboxazid

  isocarboxazid, butabarbital. Other (see comment). Contraindicated. Comment: CNS depressants such as barbiturates should not be used in combination with isocarboxazid.

• istradefylline

  butabarbital will decrease the level or effect of istradefylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of istradefylline with strong CYP3A4 inducers.

• ivosidenib

  butabarbital will decrease the level or effect of ivosidenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of ivosidenib with strong CYP3A4 inducers decreased ivosidenib plasma concentrations.

• larotrectinib

  butabarbital will increase the level or effect of larotrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of larotrectinib with strong CYP3A4 inducers is unavoidable, double larotrectinib dose. Resume prior larotrectinib dose once CYP3A4 inducer discontinued for 3-5 half-lives.

• lefamulin

  butabarbital will decrease the level or effect of lefamulin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of lefamulin with strong or moderate CYP3A inducers unless the benefit outweighs risks. Monitor for reduced efficacy.

• lemborexant

  butabarbital will decrease the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  lemborexant, butabarbital. Either increases effects of the other by sedation. Avoid or Use Alternate Drug. Use of lemborexant with other drugs to treat insomnia is not recommended.

• lovastatin

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

• lurbinectedin

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

• mestranol

  butabarbital decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. May result in contraceptive failure.

• methoxyflurane

  butabarbital increases toxicity of methoxyflurane by increasing metabolism. Contraindicated. Increased metabolism of methoxyflurane to nephrotoxic compounds.

• midostaurin

  butabarbital will decrease the level or effect of midostaurin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Strong CYP3A4 inducers may decrease midostaurin concentrations resulting in reduced efficacy.

• mobocertinib

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

• naldemedine

  butabarbital will decrease the level or effect of naldemedine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with strong CYP3A4 inducers.

• neratinib

  butabarbital will decrease 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 inducers.

• pemigatinib

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

• pexidartinib

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

• phenindione

  butabarbital decreases effects of phenindione by increasing metabolism. Avoid or Use Alternate Drug.

• pralsetinib

  butabarbital will decrease the level or effect of pralsetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid, double current pralsetinib dose starting on Day 7 of coadministration with strong CYP3A inducer. After inducer has been discontinued for at least 14 days, resume previous pralsetinib dose.

• pretomanid

  butabarbital will decrease the level or effect of pretomanid by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Pretomanid is a CYP3A4 substrate. Avoid coadministration of strong or moderate CYP3A4 inducers.

• protamine

  butabarbital decreases effects of protamine by increasing metabolism. Avoid or Use Alternate Drug.

• ranolazine

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

• rimegepant

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

• romidepsin

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

• selinexor

  selinexor, butabarbital. unspecified interaction mechanism. Avoid or Use Alternate Drug. Patients treated with selinexor may experience neurological toxicities. Avoid taking selinexor with other medications that may cause dizziness or confusion.

• selumetinib

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

• silodosin

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

• simvastatin

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

• siponimod

  butabarbital will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• sirolimus

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

• sotorasib

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

• stiripentol

  butabarbital will decrease the level or effect of stiripentol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration of stiripentol with strong CYP3A4 inducers, increase stiripentol dose.
  
  stiripentol, butabarbital. Either increases effects of the other by sedation. Avoid or Use Alternate Drug. Concomitant use stiripentol with other CNS depressants, including alcohol, may increase the risk of sedation and somnolence.

• sufentanil SL

  sufentanil SL, butabarbital. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration may result in hypotension, profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• tazemetostat

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

• tepotinib

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

• tezacaftor

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

• tivozanib

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

• tizanidine

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

• tolvaptan

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

• tucatinib

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

• ubrogepant

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

• upadacitinib

  butabarbital will increase the level or effect of upadacitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid upadacitinib coadministration with strong CYP3A4 inducers.

• valerian

  valerian increases effects of butabarbital by pharmacodynamic synergism. Avoid or Use Alternate Drug. May enhance CNS depression.
  
  valerian and butabarbital both increase sedation. Avoid or Use Alternate Drug.

• voclosporin

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

• voriconazole

  butabarbital decreases levels of voriconazole by increasing metabolism. Contraindicated.

• voxelotor

  butabarbital will decrease the level or effect of voxelotor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor is primarily metabolized by CYP3A4. Avoid coadministration with moderate or strong CYP3A4 inducers. If unable to avoid coadministration, increase voxelotor dose (see Dosage Modifications).

• warfarin

  butabarbital decreases effects of warfarin by increasing metabolism. Avoid or Use Alternate Drug.

• zanubrutinib

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

Monitor Closely (322)

• acebutolol

  butabarbital decreases levels of acebutolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• albuterol

  butabarbital increases and albuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• alfentanil

  butabarbital and alfentanil both increase sedation. Use Caution/Monitor.

• alitretinoin

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

• almotriptan

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

• alprazolam

  butabarbital will decrease the level or effect of alprazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and alprazolam both increase sedation. Use Caution/Monitor.

• amifostine

  amifostine, butabarbital. Either increases effects of the other by anti-hypertensive channel blocking. Use Caution/Monitor. Monitor hemodynamic changes, specifically for signs of hypotension, if using barbiturates with blood pressure lowering medications. .

• amiodarone

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

• amitriptyline

  butabarbital will decrease the level or effect of amitriptyline by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.
  
  butabarbital and amitriptyline both increase sedation. Use Caution/Monitor.

• amlodipine

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

• amobarbital

  amobarbital and butabarbital both increase sedation. Use Caution/Monitor.

• amoxapine

  butabarbital and amoxapine both increase sedation. Use Caution/Monitor.

• apomorphine

  butabarbital and apomorphine both increase sedation. Use Caution/Monitor.

• aprepitant

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

• arformoterol

  butabarbital increases and arformoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• aripiprazole

  butabarbital will decrease the level or effect of aripiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and aripiprazole both increase sedation. Use Caution/Monitor.

• armodafinil

  butabarbital increases and armodafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• artemether/lumefantrine

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

• atenolol

  butabarbital decreases levels of atenolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• atorvastatin

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

• avanafil

  butabarbital will decrease the level or effect of avanafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. For patients with ED, monitor response carefully because of potential for decreased effectiveness

• azelastine

  azelastine and butabarbital both increase sedation. Use Caution/Monitor.

• baclofen

  butabarbital and baclofen both increase sedation. Use Caution/Monitor.

• bazedoxifene/conjugated estrogens

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

• belladonna and opium

  butabarbital and belladonna and opium both increase sedation. Use Caution/Monitor.

• benazepril

  butabarbital increases effects of benazepril by pharmacodynamic synergism. Use Caution/Monitor. Enhanced hypotensive effects.

• bendamustine

  butabarbital decreases levels of bendamustine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. Concentrations of active metabolites may be increased.

• benperidol

  butabarbital and benperidol both increase sedation. Use Caution/Monitor.

• benzphetamine

  butabarbital increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• betaxolol

  butabarbital decreases levels of betaxolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• bexarotene

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

• bisoprolol

  butabarbital decreases levels of bisoprolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• bortezomib

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

• brexanolone

  brexanolone, butabarbital. Either increases toxicity of the other by sedation. Use Caution/Monitor.

• brompheniramine

  brompheniramine and butabarbital both increase sedation. Use Caution/Monitor.

• budesonide

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

• buprenorphine

  butabarbital and buprenorphine both increase sedation. Use Caution/Monitor.

• buprenorphine buccal

  butabarbital and buprenorphine buccal both increase sedation. Use Caution/Monitor.

• buprenorphine subdermal implant

  butabarbital will decrease 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 inducer for signs and symptoms of withdrawal. If the dose of the concomitant CYP3A4 inducer 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 inducer is discontinued in a patient who has been stabilized on buprenorphine, monitor the patient for overmedication.

• buprenorphine, long-acting injection

  butabarbital will decrease 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 inducers should be monitored to ensure buprenorphine plasma levels are adequate. If the buprenorphine dose is inadequate and the CYP3A4 inducer cannot be reduced or discontinued, transition the patient back to a buprenorphine formulation that permits dose adjustments.
  
  butabarbital increases toxicity of buprenorphine, long-acting injection by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of buprenorphine and benzodiazepines or other CNS depressants increases risk of adverse reactions including overdose, respiratory depression, and death. Cessation of benzodiazepines or other CNS depressants is preferred in most cases. In some cases, monitoring at a higher level of care for tapering CNS depressants may be appropriate. In others, gradually tapering a patient off of a prescribed benzodiazepine or other CNS depressant or decreasing to the lowest effective dose may be appropriate.

• bupropion

  butabarbital, bupropion. increasing metabolism. Use Caution/Monitor. Decr levels of bupropion, but incr levels of active metabolites. .

• buspirone

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

• butalbital

  butabarbital and butalbital both increase sedation. Use Caution/Monitor.

• butorphanol

  butabarbital and butorphanol both increase sedation. Use Caution/Monitor.

• caffeine

  butabarbital increases and caffeine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• cannabidiol

  butabarbital will decrease the level or effect of cannabidiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Consider an increase in cannabidiol dosage (based on clinical response and tolerability) when coadministered with a strong CYP3A4 inducer.

• captopril

  butabarbital, captopril. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Both drugs lower blood pressure. Monitor blood pressure.

• carbamazepine

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

• carbinoxamine

  carbinoxamine and butabarbital both increase sedation. Use Caution/Monitor.

• carisoprodol

  butabarbital and carisoprodol both increase sedation. Use Caution/Monitor.

• carvedilol

  butabarbital will decrease the level or effect of carvedilol by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
  
  butabarbital decreases levels of carvedilol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• celiprolol

  butabarbital decreases levels of celiprolol by increasing metabolism. Use Caution/Monitor. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• chloral hydrate

  butabarbital and chloral hydrate both increase sedation. Use Caution/Monitor.

• chlordiazepoxide

  butabarbital and chlordiazepoxide both increase sedation. Use Caution/Monitor.

• chlorpheniramine

  chlorpheniramine and butabarbital both increase sedation. Use Caution/Monitor.

• chlorpromazine

  butabarbital and chlorpromazine both increase sedation. Use Caution/Monitor.

• chlorzoxazone

  butabarbital and chlorzoxazone both increase sedation. Use Caution/Monitor.

• cilostazol

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

• cinacalcet

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

• cinnarizine

  cinnarizine and butabarbital both increase sedation. Use Caution/Monitor.

• clemastine

  clemastine and butabarbital both increase sedation. Use Caution/Monitor.

• clobazam

  butabarbital, clobazam. Other (see comment). Use Caution/Monitor. Comment: Concomitant administration can increase the potential for CNS effects (e.g., increased sedation or respiratory depression).

• clobetasone

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

• clomipramine

  butabarbital will decrease the level or effect of clomipramine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of clomipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.
  
  butabarbital and clomipramine both increase sedation. Use Caution/Monitor.

• clonazepam

  butabarbital and clonazepam both increase sedation. Use Caution/Monitor.

• clopidogrel

  butabarbital will increase the level or effect of clopidogrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers may increase the metabolism of clopidogrel to its active metabolite. Monitor patients for potential increase in antiplatelet effects when CYP3A4 inducers are used in combination with clopidogrel

• clorazepate

  butabarbital and clorazepate both increase sedation. Use Caution/Monitor.

• clozapine

  butabarbital will decrease the level or effect of clozapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of clozapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and clozapine both increase sedation. Use Caution/Monitor.

• codeine

  butabarbital and codeine both increase sedation. Use Caution/Monitor.

• colchicine

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

• conivaptan

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

• conjugated estrogens

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

• conjugated estrogens, vaginal

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

• cortisone

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

• cyclizine

  cyclizine and butabarbital both increase sedation. Use Caution/Monitor.

• cyclobenzaprine

  butabarbital and cyclobenzaprine both increase sedation. Use Caution/Monitor.

• cyclophosphamide

  butabarbital will decrease the level or effect of cyclophosphamide by affecting hepatic enzyme CYP2B6 metabolism. Use Caution/Monitor.

• cyclosporine

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

• cyproheptadine

  cyproheptadine and butabarbital both increase sedation. Use Caution/Monitor.

• dantrolene

  butabarbital and dantrolene both increase sedation. Use Caution/Monitor.

• darifenacin

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

• darunavir

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

• dasatinib

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

• desipramine

  butabarbital will decrease the level or effect of desipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.
  
  butabarbital and desipramine both increase sedation. Use Caution/Monitor.

• deutetrabenazine

  butabarbital and deutetrabenazine both increase sedation. Use Caution/Monitor.

• dexamethasone

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

• dexchlorpheniramine

  dexchlorpheniramine and butabarbital both increase sedation. Use Caution/Monitor.

• dexfenfluramine

  butabarbital increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dexmedetomidine

  butabarbital and dexmedetomidine both increase sedation. Use Caution/Monitor.

• dexmethylphenidate

  butabarbital increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dextroamphetamine

  butabarbital increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dextromoramide

  butabarbital and dextromoramide both increase sedation. Use Caution/Monitor.

• diamorphine

  butabarbital and diamorphine both increase sedation. Use Caution/Monitor.

• diazepam

  butabarbital will decrease the level or effect of diazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and diazepam both increase sedation. Use Caution/Monitor.

• diazepam intranasal

  butabarbital will decrease the level or effect of diazepam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong or moderate CYP3A4 inducers may increase rate of diazepam elimination; therefore, efficacy of diazepam may be decreased.
  
  diazepam intranasal, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may potentiate the CNS-depressant effects of each drug.

• diethylpropion

  butabarbital increases and diethylpropion decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• difenoxin hcl

  butabarbital and difenoxin hcl both increase sedation. Use Caution/Monitor.

• diltiazem

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

• dimenhydrinate

  dimenhydrinate and butabarbital both increase sedation. Use Caution/Monitor.

• diphenhydramine

  diphenhydramine and butabarbital both increase sedation. Use Caution/Monitor.

• diphenoxylate hcl

  butabarbital and diphenoxylate hcl both increase sedation. Use Caution/Monitor.

• dipipanone

  butabarbital and dipipanone both increase sedation. Use Caution/Monitor.

• dobutamine

  butabarbital increases and dobutamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dopamine

  butabarbital increases and dopamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dopexamine

  butabarbital increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dosulepin

  butabarbital and dosulepin both increase sedation. Use Caution/Monitor.

• doxepin

  butabarbital and doxepin both increase sedation. Use Caution/Monitor.

• doxorubicin

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

• doxorubicin liposomal

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

• doxycycline

  butabarbital decreases levels of doxycycline by increasing metabolism. Use Caution/Monitor.

• doxylamine

  butabarbital and doxylamine both increase sedation. Use Caution/Monitor.

• dronabinol

  butabarbital will decrease the level or effect of dronabinol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dronabinol is a CYP3A4 substrate.

• droperidol

  butabarbital and droperidol both increase sedation. Use Caution/Monitor.

• elagolix

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

• eletriptan

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

• eltrombopag

  butabarbital will decrease the level or effect of eltrombopag by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of eltrombopag by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

• ephedrine

  butabarbital increases and ephedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• epinephrine

  butabarbital increases and epinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• epinephrine racemic

  butabarbital increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• erlotinib

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

• escitalopram

  butabarbital will decrease the level or effect of escitalopram by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• esketamine intranasal

  esketamine intranasal, butabarbital. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.

• esmolol

  butabarbital decreases levels of esmolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• esomeprazole

  butabarbital will decrease the level or effect of esomeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• estazolam

  butabarbital and estazolam both increase sedation. Use Caution/Monitor.

• estradiol

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

• estradiol vaginal

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

• estrogens conjugated synthetic

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

• estrogens esterified

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

• estropipate

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

• ethanol

  butabarbital and ethanol both increase sedation. Use Caution/Monitor.

• ethotoin

  butabarbital will decrease the level or effect of ethotoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

• etomidate

  etomidate and butabarbital both increase sedation. Use Caution/Monitor.

• etonogestrel

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

• etoposide

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

• etravirine

  butabarbital will decrease the level or effect of etravirine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of etravirine by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of etravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• exemestane

  butabarbital will decrease the level or effect of exemestane by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. For patients receiving exemestane with a potent CYP3A4 inducer the recommended dose of exemestane is 50 mg daily after a meal.

• felodipine

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

• fenfluramine

  butabarbital increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• fesoterodine

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

• flibanserin

  butabarbital and flibanserin both increase sedation. Modify Therapy/Monitor Closely. Risk for sedation increased if flibanserin is coadministration with other CNS depressants.

• fludrocortisone

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

• fluphenazine

  butabarbital and fluphenazine both increase sedation. Use Caution/Monitor.

• flurazepam

  butabarbital and flurazepam both increase sedation. Use Caution/Monitor.

• formoterol

  butabarbital increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• fosamprenavir

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

• fosphenytoin

  butabarbital will decrease the level or effect of fosphenytoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

• gabapentin

  gabapentin, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.

• gabapentin enacarbil

  gabapentin enacarbil, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.

• glecaprevir/pibrentasvir

  butabarbital will decrease the level or effect of glecaprevir/pibrentasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of drugs that induce CYP3A4 with glecaprevir/pibrentasvir may decrease glecaprevir/pibrentasvir plasma concentrations. Potential for loss of therapeutic effect.

• gotu kola

  gotu kola increases effects of butabarbital by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.

• guanfacine

  butabarbital will decrease the level or effect of guanfacine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong or moderate CYP3A4 inducers significantly reduce guanfacine plasma concentrations and elimination half-life. If coadministered, more frequent dosing of the IR product may be required to achieve or maintain the desired hypotensive response. For patients with ADHD, FDA-approved labeling for ER guanfacine recommends that, if coadministered, doubling the recommended dose of guanfacine should be considered.

• haloperidol

  butabarbital and haloperidol both increase sedation. Use Caution/Monitor.

• hawthorn

  hawthorn increases effects of butabarbital by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.

• hemin

  butabarbital decreases effects of hemin by pharmacodynamic antagonism. Use Caution/Monitor. Drugs that increase delta-aminolevulinic acid synthetase may decrease hemin effect.

• hops

  hops increases effects of butabarbital by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.

• hydrocortisone

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

• hydromorphone

  butabarbital and hydromorphone both increase sedation. Use Caution/Monitor.

• hydroxyprogesterone caproate

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

• hydroxyzine

  hydroxyzine and butabarbital both increase sedation. Use Caution/Monitor.

• ifosfamide

  butabarbital increases effects of ifosfamide by affecting hepatic enzyme CYP2B6 metabolism. Use Caution/Monitor. Coadministration of ifosfamide with CYP2B6 inducers may increase metabolism of ifosfamide to its metabolite. Monitor for increased effects/toxicities if combined with CYP2B6 inducers.
  
  butabarbital increases effects of ifosfamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers may increase the metabolism of ifosfamide to its active alkylating metabolites. CYP3A4 inducers may increase the formation of the neurotoxic/nephrotoxic ifosfamide metabolite, chloroacetaldehyde. Closely monitor patients taking ifosfamide with CYP3A4 inducers for toxicities and consider dose adjustment.

• iloperidone

  butabarbital will decrease the level or effect of iloperidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and iloperidone both increase sedation. Use Caution/Monitor.

• imipramine

  butabarbital will decrease the level or effect of imipramine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of imipramine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of imipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.
  
  butabarbital and imipramine both increase sedation. Use Caution/Monitor.

• indinavir

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

• isoproterenol

  butabarbital increases and isoproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• ixabepilone

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

• kava

  kava increases effects of butabarbital by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.

• ketamine

  ketamine and butabarbital both increase sedation. Use Caution/Monitor.

• ketotifen, ophthalmic

  butabarbital and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.

• labetalol

  butabarbital decreases levels of labetalol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• lapatinib

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

• lasmiditan

  lasmiditan, butabarbital. Either increases effects of the other by sedation. Use Caution/Monitor. Coadministration of lasmiditan and other CNS depressant drugs, including alcohol have not been evaluated in clinical studies. Lasmiditan may cause sedation, as well as other cognitive and/or neuropsychiatric adverse reactions.

• levalbuterol

  butabarbital increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• levamlodipine

  butabarbital will decrease the level or effect of levamlodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No information is available on the quantitative effects of CYP3A4 inducers on amlodipine. Closely monitor blood pressure when amlodipine is coadministered with CYP3A4 inducers.

• levonorgestrel oral/ethinylestradiol/ferrous bisglycinate

  butabarbital will decrease the level or effect of levonorgestrel oral/ethinylestradiol/ferrous bisglycinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. The efficacy of hormonal contraceptives may be reduced. Use an alternative method of contraception or a backup method when enzyme inducers are used with combined hormonal contraceptives (CHCs), and continue backup contraception for 28 days after discontinuing enzyme inducer to ensure contraceptive reliability.

• levorphanol

  butabarbital and levorphanol both increase sedation. Use Caution/Monitor.

• lidocaine

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

• lisdexamfetamine

  butabarbital increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• lofepramine

  butabarbital and lofepramine both increase sedation. Use Caution/Monitor.

• lofexidine

  butabarbital and lofexidine both increase sedation. Use Caution/Monitor.

• lopinavir

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

• loprazolam

  butabarbital and loprazolam both increase sedation. Use Caution/Monitor.

• loratadine

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

• lorazepam

  butabarbital and lorazepam both increase sedation. Use Caution/Monitor.

• lormetazepam

  butabarbital and lormetazepam both increase sedation. Use Caution/Monitor.

• loxapine

  butabarbital and loxapine both increase sedation. Use Caution/Monitor.

• loxapine inhaled

  butabarbital and loxapine inhaled both increase sedation. Use Caution/Monitor.

• lumefantrine

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

• lurasidone

  lurasidone, butabarbital. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Potential for increased CNS depressant effects when used concurrently; monitor for increased adverse effects and toxicity.

• maprotiline

  butabarbital and maprotiline both increase sedation. Use Caution/Monitor.

• maraviroc

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

• marijuana

  butabarbital and marijuana both increase sedation. Use Caution/Monitor.

• melatonin

  butabarbital and melatonin both increase sedation. Use Caution/Monitor.

• meperidine

  butabarbital and meperidine both increase sedation. Use Caution/Monitor.

• meprobamate

  butabarbital and meprobamate both increase sedation. Use Caution/Monitor.

• mestranol

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

• metaproterenol

  butabarbital increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• metaxalone

  butabarbital and metaxalone both increase sedation. Use Caution/Monitor.

• methadone

  butabarbital will decrease the level or effect of methadone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and methadone both increase sedation. Use Caution/Monitor.

• methamphetamine

  butabarbital increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• methocarbamol

  butabarbital and methocarbamol both increase sedation. Use Caution/Monitor.

• methylenedioxymethamphetamine

  butabarbital increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• methylprednisolone

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

• metoprolol

  butabarbital decreases levels of metoprolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• mexiletine

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

• midazolam

  butabarbital will decrease the level or effect of midazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and midazolam both increase sedation. Use Caution/Monitor.

• midazolam intranasal

  midazolam intranasal, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase the risk of hypoventilation, airway obstruction, desaturation, or apnea and may contribute to profound and/or prolonged drug effect.

• midodrine

  butabarbital increases and midodrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• mirtazapine

  butabarbital and mirtazapine both increase sedation. Use Caution/Monitor.

• modafinil

  butabarbital increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• morphine

  butabarbital and morphine both increase sedation. Use Caution/Monitor.

• motherwort

  butabarbital and motherwort both increase sedation. Use Caution/Monitor.

• moxonidine

  butabarbital and moxonidine both increase sedation. Use Caution/Monitor.

• nabilone

  butabarbital and nabilone both increase sedation. Use Caution/Monitor.

• nadolol

  butabarbital decreases levels of nadolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• nalbuphine

  butabarbital and nalbuphine both increase sedation. Use Caution/Monitor.

• nateglinide

  butabarbital will decrease the level or effect of nateglinide by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

• nebivolol

  butabarbital decreases levels of nebivolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• nelfinavir

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

• nicardipine

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

• nilotinib

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

• nisoldipine

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

• norepinephrine

  butabarbital increases and norepinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• nortriptyline

  butabarbital and nortriptyline both increase sedation. Use Caution/Monitor.

• olanzapine

  butabarbital will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  butabarbital and olanzapine both increase sedation. Use Caution/Monitor.

• oliceridine

  butabarbital will decrease the level or effect of oliceridine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. If coadministration with a CYP3A4 inducer is necessary, consider increasing oliceridine dose until stable drug effects are achieved; monitor for signs of opioid withdrawal. If inducer is discontinued, consider oliceridine dosage reduction and monitor for signs of respiratory depression.
  
  oliceridine, butabarbital. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• omeprazole

  butabarbital will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• ondansetron

  butabarbital will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.

• opium tincture

  butabarbital and opium tincture both increase sedation. Use Caution/Monitor.

• orphenadrine

  butabarbital and orphenadrine both increase sedation. Use Caution/Monitor.

• osilodrostat

  butabarbital will decrease the level or effect of osilodrostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor cortisol concentration and patient?s signs and symptoms during coadministration or discontinuation with strong CYP3A4 inducers. Adjust dose of osilodrostat if necessary.

• oxazepam

  butabarbital and oxazepam both increase sedation. Use Caution/Monitor.

• oxycodone

  butabarbital and oxycodone both increase sedation. Use Caution/Monitor.

• oxymorphone

  butabarbital and oxymorphone both increase sedation. Use Caution/Monitor.

• paliperidone

  butabarbital and paliperidone both increase sedation. Use Caution/Monitor.

• pantoprazole

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

• papaveretum

  butabarbital and papaveretum both increase sedation. Use Caution/Monitor.

• papaverine

  butabarbital and papaverine both increase sedation. Use Caution/Monitor.

• parecoxib

  butabarbital will decrease the level or effect of parecoxib by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

• passion flower

  passion flower increases effects of butabarbital by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.

• pazopanib

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

• penbutolol

  butabarbital decreases levels of penbutolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• pentazocine

  butabarbital and pentazocine both increase sedation. Use Caution/Monitor.

• pentobarbital

  butabarbital and pentobarbital both increase sedation. Use Caution/Monitor.

• perphenazine

  butabarbital and perphenazine both increase sedation. Use Caution/Monitor.

• phendimetrazine

  butabarbital increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• phenobarbital

  butabarbital and phenobarbital both increase sedation. Use Caution/Monitor.

• phentermine

  butabarbital increases and phentermine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• phenylephrine

  butabarbital increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• phenylephrine PO

  butabarbital increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .

• phenytoin

  butabarbital will decrease the level or effect of phenytoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

• pholcodine

  butabarbital and pholcodine both increase sedation. Use Caution/Monitor.

• pimozide

  butabarbital and pimozide both increase sedation. Use Caution/Monitor.

• pindolol

  butabarbital decreases levels of pindolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• pirbuterol

  butabarbital increases and pirbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• pitolisant

  butabarbital will decrease the level or effect of pitolisant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Pitolisant exposure is decreased by 50% if coadministered with strong CYP3A4 inducers. For patients stable on pitolisant 8.9 mg/day or 17.8 mg/day, double the pitolisant dose (ie, 17.8 mg or 35.6 mg, respectively) over 7 days. If the strong CYP3A4 inducer is discontinued, reduce pitolisant dosage by half.

• polatuzumab vedotin

  butabarbital will decrease the level or effect of polatuzumab vedotin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Polatuzumab undergoes catabolism to small peptides, amino acids, monomethyl auristatin E (MMAE), and unconjugated MMAE-related catabolites. MMAE is a CYP3A4 substrate. Coadministration of polatuzumab vedotin with a strong CYP3A4 inducer may decrease unconjugated MMAE AUC.

• prednisolone

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

• prednisone

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

• pregabalin

  pregabalin, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.

• primidone

  butabarbital and primidone both increase sedation. Use Caution/Monitor.

• prochlorperazine

  butabarbital and prochlorperazine both increase sedation. Use Caution/Monitor.

• promethazine

  promethazine and butabarbital both increase sedation. Use Caution/Monitor.

• propafenone

  butabarbital decreases levels of propafenone by increasing metabolism. Use Caution/Monitor.

• propofol

  propofol and butabarbital both increase sedation. Use Caution/Monitor.

• propranolol

  butabarbital decreases levels of propranolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• propylhexedrine

  butabarbital increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• protriptyline

  butabarbital and protriptyline both increase sedation. Use Caution/Monitor.

• quazepam

  butabarbital and quazepam both increase sedation. Use Caution/Monitor.

• quetiapine

  butabarbital will decrease the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and quetiapine both increase sedation. Use Caution/Monitor.

• quinidine

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

• ramelteon

  butabarbital will decrease the level or effect of ramelteon by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  butabarbital and ramelteon both increase sedation. Use Caution/Monitor.

• remimazolam

  remimazolam, butabarbital. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely. Coadministration may result in profound sedation, respiratory depression, coma, and/or death. Continuously monitor vital signs during sedation and recovery period if coadministered. Carefully titrate remimazolam dose if administered with opioid analgesics and/or sedative/hypnotics.

• repaglinide

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

• rifampin

  rifampin decreases levels of butabarbital by increasing metabolism. Use Caution/Monitor.

• risperidone

  butabarbital and risperidone both increase sedation. Use Caution/Monitor.

• ritonavir

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

• salmeterol

  butabarbital increases and salmeterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• saquinavir

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

• scullcap

  butabarbital and scullcap both increase sedation. Use Caution/Monitor.

• secobarbital

  butabarbital and secobarbital both increase sedation. Use Caution/Monitor.

• shepherd's purse

  butabarbital and shepherd's purse both increase sedation. Use Caution/Monitor.

• sildenafil

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

• solifenacin

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

• sorafenib

  butabarbital decreases levels of sorafenib by increasing metabolism. Use Caution/Monitor.

• sotalol

  butabarbital decreases levels of sotalol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• sufentanil

  butabarbital and sufentanil both increase sedation. Use Caution/Monitor.

• sufentanil SL

  butabarbital decreases effects of sufentanil SL by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration of CYP3A4 inducers may decrease sufentanil levels and efficacy, possibly precipitating withdrawal syndrome in patients who have developed physical dependence to sufentanil. Discontinuation of concomitantly used CYP3A4 inducers may increase sufentanil plasma concentration.

• sunitinib

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

• tacrolimus

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

• tadalafil

  butabarbital will decrease the level or effect of tadalafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Avoid combination in pulmonary HTN patients. For patients with ED, monitor response to tadalafil carefully because of potential for decreased effectiveness.

• tamoxifen

  butabarbital will decrease the level or effect of tamoxifen by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of tamoxifen by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tapentadol

  butabarbital and tapentadol both increase sedation. Use Caution/Monitor.

• temazepam

  butabarbital and temazepam both increase sedation. Use Caution/Monitor.

• temsirolimus

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

• terbinafine

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

• terbutaline

  butabarbital increases and terbutaline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• thalidomide

  thalidomide increases effects of butabarbital by unspecified interaction mechanism. Use Caution/Monitor. Increased sedative effects.

• theophylline

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

• thioridazine

  butabarbital and thioridazine both increase sedation. Use Caution/Monitor.

• thiothixene

  butabarbital and thiothixene both increase sedation. Use Caution/Monitor.

• timolol

  butabarbital decreases levels of timolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• tinidazole

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

• tipranavir

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

• tolterodine

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

• topiramate

  butabarbital and topiramate both increase sedation. Modify Therapy/Monitor Closely.

• tramadol

  butabarbital and tramadol both increase sedation. Use Caution/Monitor.

• trazodone

  butabarbital will decrease the level or effect of trazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and trazodone both increase sedation. Use Caution/Monitor.

• triamcinolone acetonide injectable suspension

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

• triazolam

  butabarbital will decrease the level or effect of triazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and triazolam both increase sedation. Use Caution/Monitor.

• triclofos

  butabarbital and triclofos both increase sedation. Use Caution/Monitor.

• trifluoperazine

  butabarbital and trifluoperazine both increase sedation. Use Caution/Monitor.

• trimipramine

  butabarbital and trimipramine both increase sedation. Use Caution/Monitor.

• triprolidine

  triprolidine and butabarbital both increase sedation. Use Caution/Monitor.

• vardenafil

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

• verapamil

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

• warfarin

  butabarbital will decrease the level or effect of warfarin by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of warfarin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of warfarin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• xylometazoline

  butabarbital increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• yohimbine

  butabarbital increases and yohimbine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• ziconotide

  butabarbital and ziconotide both increase sedation. Use Caution/Monitor.

• ziprasidone

  butabarbital and ziprasidone both increase sedation. Use Caution/Monitor.

• zotepine

  butabarbital and zotepine both increase sedation. Use Caution/Monitor.

Minor (116)

• acetazolamide

  acetazolamide, butabarbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Increased risk of anticonvulsant induced osteomalacia.

• alfentanil

  butabarbital will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• alfuzosin

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

• alosetron

  butabarbital will decrease the level or effect of alosetron by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
  
  butabarbital will decrease the level or effect of alosetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• amitriptyline

  butabarbital, amitriptyline. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• amoxapine

  butabarbital, amoxapine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• amphotericin B deoxycholate

  butabarbital decreases levels of amphotericin B deoxycholate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• antipyrine

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

• armodafinil

  butabarbital will decrease the level or effect of armodafinil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ascorbic acid

  butabarbital decreases levels of ascorbic acid by increasing elimination. Minor/Significance Unknown.

• asenapine

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

• ashwagandha

  ashwagandha increases effects of butabarbital by pharmacodynamic synergism. Minor/Significance Unknown. May enhance CNS depression.

• atazanavir

  butabarbital will decrease the level or effect of atazanavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• bosentan

  butabarbital will decrease the level or effect of bosentan by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
  
  butabarbital will decrease the level or effect of bosentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• brimonidine

  brimonidine increases effects of butabarbital by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• brinzolamide

  brinzolamide, butabarbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Increased risk of anticonvulsant induced osteomalacia.

• caffeine

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

• celecoxib

  butabarbital will decrease the level or effect of celecoxib by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• cevimeline

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

• chloramphenicol

  chloramphenicol increases levels of butabarbital by decreasing metabolism. Minor/Significance Unknown.
  
  butabarbital decreases levels of chloramphenicol by increasing metabolism. Minor/Significance Unknown.

• chlorpromazine

  butabarbital decreases levels of chlorpromazine by increasing metabolism. Minor/Significance Unknown.

• cimetidine

  butabarbital will decrease the level or effect of cimetidine by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• clarithromycin

  butabarbital will decrease the level or effect of clarithromycin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  butabarbital decreases levels of clarithromycin by increasing elimination. Minor/Significance Unknown.

• clomipramine

  butabarbital, clomipramine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• clotrimazole

  butabarbital decreases levels of clotrimazole by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• cocaine

  butabarbital will decrease the level or effect of cocaine by affecting hepatic enzyme CYP2B6 metabolism. Minor/Significance Unknown.

• dapsone

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

• desipramine

  butabarbital, desipramine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• diclofenac

  butabarbital will decrease the level or effect of diclofenac by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• disopyramide

  butabarbital will decrease the level or effect of disopyramide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• docetaxel

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

• donepezil

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

• dosulepin

  butabarbital, dosulepin. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• doxepin

  butabarbital, doxepin. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• dutasteride

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

• efavirenz

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

• eplerenone

  butabarbital will decrease the level or effect of eplerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• erythromycin base

  butabarbital decreases levels of erythromycin base by increasing elimination. Minor/Significance Unknown.

• erythromycin ethylsuccinate

  butabarbital decreases levels of erythromycin ethylsuccinate by increasing elimination. Minor/Significance Unknown.

• erythromycin lactobionate

  butabarbital decreases levels of erythromycin lactobionate by increasing elimination. Minor/Significance Unknown.

• erythromycin stearate

  butabarbital decreases levels of erythromycin stearate by increasing elimination. Minor/Significance Unknown.

• ethosuximide

  ethosuximide decreases effects of butabarbital by pharmacodynamic antagonism. Minor/Significance Unknown.

• eucalyptus

  butabarbital will decrease the level or effect of eucalyptus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  butabarbital and eucalyptus both increase sedation. Minor/Significance Unknown.

• finasteride

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

• fluconazole

  butabarbital decreases levels of fluconazole by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• flurbiprofen

  butabarbital will decrease the level or effect of flurbiprofen by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• frovatriptan

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

• galantamine

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

• griseofulvin

  butabarbital decreases levels of griseofulvin by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• haloperidol

  haloperidol, butabarbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hyperthermia if haloperidol admin. during barbiturate withdrawal.

• ibuprofen

  butabarbital will decrease the level or effect of ibuprofen by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• ibuprofen IV

  butabarbital will decrease the level or effect of ibuprofen IV by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• imatinib

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

• imipramine

  butabarbital, imipramine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• isocarboxazid

  isocarboxazid increases levels of butabarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.

• isradipine

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

• ketoconazole

  butabarbital will decrease the level or effect of ketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  butabarbital decreases levels of ketoconazole by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• lansoprazole

  butabarbital will decrease the level or effect of lansoprazole by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• levothyroxine

  butabarbital decreases levels of levothyroxine by increasing metabolism. Minor/Significance Unknown.

• linezolid

  linezolid increases levels of butabarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.

• liothyronine

  butabarbital decreases levels of liothyronine by increasing metabolism. Minor/Significance Unknown.

• lofepramine

  butabarbital, lofepramine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• losartan

  butabarbital will decrease the level or effect of losartan by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• maprotiline

  butabarbital, maprotiline. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• meloxicam

  butabarbital will decrease the level or effect of meloxicam by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• methazolamide

  methazolamide, butabarbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Increased risk of anticonvulsant induced osteomalacia.

• methsuximide

  methsuximide decreases effects of butabarbital by pharmacodynamic antagonism. Minor/Significance Unknown.

• miconazole vaginal

  butabarbital decreases levels of miconazole vaginal by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• montelukast

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

• nettle

  nettle increases effects of butabarbital by pharmacodynamic synergism. Minor/Significance Unknown. (High dose nettle; theoretical interaction) May enhance CNS depression.

• nifedipine

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

• nimodipine

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

• nitrendipine

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

• nortriptyline

  butabarbital, nortriptyline. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• ondansetron

  butabarbital will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• oxybutynin

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

• paclitaxel

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

• paclitaxel protein bound

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

• parecoxib

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

• phenelzine

  phenelzine increases levels of butabarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.

• pimozide

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

• pioglitazone

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

• piroxicam

  butabarbital will decrease the level or effect of piroxicam by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• posaconazole

  butabarbital decreases levels of posaconazole by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• procarbazine

  procarbazine increases levels of butabarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.

• propafenone

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

• protriptyline

  butabarbital, protriptyline. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• quinine

  butabarbital will decrease the level or effect of quinine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• rabeprazole

  butabarbital will decrease the level or effect of rabeprazole by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.
  
  butabarbital will decrease the level or effect of rabeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ramelteon

  butabarbital will decrease the level or effect of ramelteon by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
  
  butabarbital will decrease the level or effect of ramelteon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• riluzole

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

• rose hips

  butabarbital decreases levels of rose hips by increasing elimination. Minor/Significance Unknown.

• sage

  butabarbital and sage both increase sedation. Minor/Significance Unknown.

• saxagliptin

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

• selegiline transdermal

  selegiline transdermal increases levels of butabarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.

• Siberian ginseng

  Siberian ginseng increases effects of butabarbital by pharmacodynamic synergism. Minor/Significance Unknown. May enhance CNS depression.

• sufentanil

  butabarbital will decrease the level or effect of sufentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• sulfamethoxazole

  butabarbital will decrease the level or effect of sulfamethoxazole by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• thioridazine

  thioridazine decreases levels of butabarbital by unspecified interaction mechanism. Minor/Significance Unknown.

• thyroid desiccated

  butabarbital decreases levels of thyroid desiccated by increasing metabolism. Minor/Significance Unknown.

• tibolone

  butabarbital decreases levels of tibolone by increasing metabolism. Minor/Significance Unknown. Theoretical interaction.

• tolbutamide

  butabarbital will decrease the level or effect of tolbutamide by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• topiramate

  butabarbital decreases levels of topiramate by increasing metabolism. Minor/Significance Unknown.

• tranylcypromine

  tranylcypromine increases levels of butabarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.

• trazodone

  butabarbital, trazodone. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• trimipramine

  butabarbital, trimipramine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• vinblastine

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

• vincristine

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

• vincristine liposomal

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

• vinorelbine

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

• voriconazole

  butabarbital will decrease the level or effect of voriconazole by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.
  
  butabarbital will decrease the level or effect of voriconazole by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• warfarin

  butabarbital will decrease the level or effect of warfarin by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• zaleplon

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

• ziprasidone

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

• zolpidem

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

• zonisamide

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

• abemaciclib

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of abemaciclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of abemaciclib with strong CYP3A4 inducers reduces plasma concentration of abemaciclib and its metabolites.

• acalabrutinib

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of acalabrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of acalabrutinib with strong CYP3A inducers. If a strong CYP3A inducer must be used, increase acalabrutinib dose to 200 mg twice daily.

• acebutolol

  Monitor Closely (1)butabarbital decreases levels of acebutolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• acetazolamide

  Minor (1)acetazolamide, butabarbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Increased risk of anticonvulsant induced osteomalacia.

• albuterol

  Monitor Closely (1)butabarbital increases and albuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• alfentanil

  Monitor Closely (1)butabarbital and alfentanil both increase sedation. Use Caution/Monitor.Minor (1)butabarbital will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• alfuzosin

  Minor (1)butabarbital will decrease the level or effect of alfuzosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• alitretinoin

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

• almotriptan

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

• alosetron

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of alosetron by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug.Minor (2)butabarbital will decrease the level or effect of alosetron by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
  
  butabarbital will decrease the level or effect of alosetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• alpelisib

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of alpelisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of alpelisib (CYP3A4 substrate) with strong CYP3A4 inducers.

• alprazolam

  Monitor Closely (2)butabarbital will decrease the level or effect of alprazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and alprazolam both increase sedation. Use Caution/Monitor.

• amifostine

  Monitor Closely (1)amifostine, butabarbital. Either increases effects of the other by anti-hypertensive channel blocking. Use Caution/Monitor. Monitor hemodynamic changes, specifically for signs of hypotension, if using barbiturates with blood pressure lowering medications. .

• amiodarone

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

• amitriptyline

  Monitor Closely (3)butabarbital will decrease the level or effect of amitriptyline by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.
  
  butabarbital and amitriptyline both increase sedation. Use Caution/Monitor.Minor (1)butabarbital, amitriptyline. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• amlodipine

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

• amobarbital

  Monitor Closely (1)amobarbital and butabarbital both increase sedation. Use Caution/Monitor.

• amoxapine

  Monitor Closely (1)butabarbital and amoxapine both increase sedation. Use Caution/Monitor.Minor (1)butabarbital, amoxapine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• amphotericin B deoxycholate

  Minor (1)butabarbital decreases levels of amphotericin B deoxycholate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• antipyrine

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

• antithrombin alfa

  Serious - Use Alternative (1)butabarbital decreases effects of antithrombin alfa by increasing metabolism. Avoid or Use Alternate Drug.

• antithrombin III

  Serious - Use Alternative (1)butabarbital decreases effects of antithrombin III by increasing metabolism. Avoid or Use Alternate Drug.

• apomorphine

  Monitor Closely (1)butabarbital and apomorphine both increase sedation. Use Caution/Monitor.

• aprepitant

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

• arformoterol

  Monitor Closely (1)butabarbital increases and arformoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• argatroban

  Serious - Use Alternative (1)butabarbital decreases effects of argatroban by increasing metabolism. Avoid or Use Alternate Drug.

• aripiprazole

  Monitor Closely (2)butabarbital will decrease the level or effect of aripiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and aripiprazole both increase sedation. Use Caution/Monitor.

• armodafinil

  Monitor Closely (1)butabarbital increases and armodafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)butabarbital will decrease the level or effect of armodafinil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• artemether/lumefantrine

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

• ascorbic acid

  Minor (1)butabarbital decreases levels of ascorbic acid by increasing elimination. Minor/Significance Unknown.

• asenapine

  Minor (1)butabarbital will decrease the level or effect of asenapine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• ashwagandha

  Minor (1)ashwagandha increases effects of butabarbital by pharmacodynamic synergism. Minor/Significance Unknown. May enhance CNS depression.

• atazanavir

  Minor (1)butabarbital will decrease the level or effect of atazanavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• atenolol

  Monitor Closely (1)butabarbital decreases levels of atenolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• atorvastatin

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

• avanafil

  Monitor Closely (1)butabarbital will decrease the level or effect of avanafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. For patients with ED, monitor response carefully because of potential for decreased effectiveness

• avapritinib

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

• azelastine

  Monitor Closely (1)azelastine and butabarbital both increase sedation. Use Caution/Monitor.

• baclofen

  Monitor Closely (1)butabarbital and baclofen both increase sedation. Use Caution/Monitor.

• bazedoxifene/conjugated estrogens

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

• belladonna and opium

  Monitor Closely (1)butabarbital and belladonna and opium both increase sedation. Use Caution/Monitor.

• bemiparin

  Serious - Use Alternative (1)butabarbital decreases effects of bemiparin by increasing metabolism. Avoid or Use Alternate Drug.

• benazepril

  Monitor Closely (1)butabarbital increases effects of benazepril by pharmacodynamic synergism. Use Caution/Monitor. Enhanced hypotensive effects.

• bendamustine

  Monitor Closely (1)butabarbital decreases levels of bendamustine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. Concentrations of active metabolites may be increased.

• benperidol

  Monitor Closely (1)butabarbital and benperidol both increase sedation. Use Caution/Monitor.

• benzhydrocodone/acetaminophen

  Serious - Use Alternative (1)benzhydrocodone/acetaminophen, butabarbital. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• benzphetamine

  Monitor Closely (1)butabarbital increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• betaxolol

  Monitor Closely (1)butabarbital decreases levels of betaxolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• bexarotene

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

• bisoprolol

  Monitor Closely (1)butabarbital decreases levels of bisoprolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• bivalirudin

  Serious - Use Alternative (1)butabarbital decreases effects of bivalirudin by increasing metabolism. Avoid or Use Alternate Drug.

• bortezomib

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

• bosentan

  Minor (2)butabarbital will decrease the level or effect of bosentan by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
  
  butabarbital will decrease the level or effect of bosentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• brexanolone

  Monitor Closely (1)brexanolone, butabarbital. Either increases toxicity of the other by sedation. Use Caution/Monitor.

• brigatinib

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of brigatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration with strong CYP3A4 inducers may decrease brigatinib efficacy.

• brimonidine

  Minor (1)brimonidine increases effects of butabarbital by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• brinzolamide

  Minor (1)brinzolamide, butabarbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Increased risk of anticonvulsant induced osteomalacia.

• brompheniramine

  Monitor Closely (1)brompheniramine and butabarbital both increase sedation. Use Caution/Monitor.

• budesonide

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

• buprenorphine

  Monitor Closely (1)butabarbital and buprenorphine both increase sedation. Use Caution/Monitor.

• buprenorphine buccal

  Monitor Closely (1)butabarbital and buprenorphine buccal both increase sedation. Use Caution/Monitor.

• buprenorphine subdermal implant

  Monitor Closely (1)butabarbital will decrease 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 inducer for signs and symptoms of withdrawal. If the dose of the concomitant CYP3A4 inducer 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 inducer is discontinued in a patient who has been stabilized on buprenorphine, monitor the patient for overmedication.

• buprenorphine, long-acting injection

  Monitor Closely (2)butabarbital will decrease 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 inducers should be monitored to ensure buprenorphine plasma levels are adequate. If the buprenorphine dose is inadequate and the CYP3A4 inducer cannot be reduced or discontinued, transition the patient back to a buprenorphine formulation that permits dose adjustments.
  
  butabarbital increases toxicity of buprenorphine, long-acting injection by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of buprenorphine and benzodiazepines or other CNS depressants increases risk of adverse reactions including overdose, respiratory depression, and death. Cessation of benzodiazepines or other CNS depressants is preferred in most cases. In some cases, monitoring at a higher level of care for tapering CNS depressants may be appropriate. In others, gradually tapering a patient off of a prescribed benzodiazepine or other CNS depressant or decreasing to the lowest effective dose may be appropriate.

• bupropion

  Monitor Closely (1)butabarbital, bupropion. increasing metabolism. Use Caution/Monitor. Decr levels of bupropion, but incr levels of active metabolites. .

• buspirone

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

• butalbital

  Monitor Closely (1)butabarbital and butalbital both increase sedation. Use Caution/Monitor.

• butorphanol

  Monitor Closely (1)butabarbital and butorphanol both increase sedation. Use Caution/Monitor.

• caffeine

  Monitor Closely (1)butabarbital increases and caffeine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)butabarbital will decrease the level or effect of caffeine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• calcium/magnesium/potassium/sodium oxybates

  Contraindicated (1)butabarbital, calcium/magnesium/potassium/sodium oxybates. Either increases effects of the other by pharmacodynamic synergism. Contraindicated. Coadministration with alcohol or sedative hypnotics are contraindicated because of additive CNS depression.

• cannabidiol

  Monitor Closely (1)butabarbital will decrease the level or effect of cannabidiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Consider an increase in cannabidiol dosage (based on clinical response and tolerability) when coadministered with a strong CYP3A4 inducer.

• captopril

  Monitor Closely (1)butabarbital, captopril. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Both drugs lower blood pressure. Monitor blood pressure.

• carbamazepine

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

• carbinoxamine

  Monitor Closely (1)carbinoxamine and butabarbital both increase sedation. Use Caution/Monitor.

• carisoprodol

  Monitor Closely (1)butabarbital and carisoprodol both increase sedation. Use Caution/Monitor.

• carvedilol

  Monitor Closely (2)butabarbital will decrease the level or effect of carvedilol by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
  
  butabarbital decreases levels of carvedilol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• celecoxib

  Minor (1)butabarbital will decrease the level or effect of celecoxib by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• celiprolol

  Monitor Closely (1)butabarbital decreases levels of celiprolol by increasing metabolism. Use Caution/Monitor. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• cevimeline

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

• chloral hydrate

  Monitor Closely (1)butabarbital and chloral hydrate both increase sedation. Use Caution/Monitor.

• chloramphenicol

  Minor (2)chloramphenicol increases levels of butabarbital by decreasing metabolism. Minor/Significance Unknown.
  
  butabarbital decreases levels of chloramphenicol by increasing metabolism. Minor/Significance Unknown.

• chlordiazepoxide

  Monitor Closely (1)butabarbital and chlordiazepoxide both increase sedation. Use Caution/Monitor.

• chlorpheniramine

  Monitor Closely (1)chlorpheniramine and butabarbital both increase sedation. Use Caution/Monitor.

• chlorpromazine

  Monitor Closely (1)butabarbital and chlorpromazine both increase sedation. Use Caution/Monitor.Minor (1)butabarbital decreases levels of chlorpromazine by increasing metabolism. Minor/Significance Unknown.

• chlorzoxazone

  Monitor Closely (1)butabarbital and chlorzoxazone both increase sedation. Use Caution/Monitor.

• cilostazol

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

• cimetidine

  Minor (1)butabarbital will decrease the level or effect of cimetidine by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• cinacalcet

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

• cinnarizine

  Monitor Closely (1)cinnarizine and butabarbital both increase sedation. Use Caution/Monitor.

• clarithromycin

  Minor (2)butabarbital will decrease the level or effect of clarithromycin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  butabarbital decreases levels of clarithromycin by increasing elimination. Minor/Significance Unknown.

• clemastine

  Monitor Closely (1)clemastine and butabarbital both increase sedation. Use Caution/Monitor.

• clobazam

  Monitor Closely (1)butabarbital, clobazam. Other (see comment). Use Caution/Monitor. Comment: Concomitant administration can increase the potential for CNS effects (e.g., increased sedation or respiratory depression).

• clobetasone

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

• clomipramine

  Monitor Closely (3)butabarbital will decrease the level or effect of clomipramine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of clomipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.
  
  butabarbital and clomipramine both increase sedation. Use Caution/Monitor.Minor (1)butabarbital, clomipramine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• clonazepam

  Monitor Closely (1)butabarbital and clonazepam both increase sedation. Use Caution/Monitor.

• clopidogrel

  Monitor Closely (1)butabarbital will increase the level or effect of clopidogrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers may increase the metabolism of clopidogrel to its active metabolite. Monitor patients for potential increase in antiplatelet effects when CYP3A4 inducers are used in combination with clopidogrel

• clorazepate

  Monitor Closely (1)butabarbital and clorazepate both increase sedation. Use Caution/Monitor.

• clotrimazole

  Minor (1)butabarbital decreases levels of clotrimazole by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• clozapine

  Monitor Closely (3)butabarbital will decrease the level or effect of clozapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of clozapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and clozapine both increase sedation. Use Caution/Monitor.

• cocaine

  Minor (1)butabarbital will decrease the level or effect of cocaine by affecting hepatic enzyme CYP2B6 metabolism. Minor/Significance Unknown.

• codeine

  Monitor Closely (1)butabarbital and codeine both increase sedation. Use Caution/Monitor.

• colchicine

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

• conivaptan

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

• conjugated estrogens

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

• conjugated estrogens, vaginal

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

• copanlisib

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of copanlisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of copanlisib with strong CYP3A4 inducers.

• cortisone

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

• cyclizine

  Monitor Closely (1)cyclizine and butabarbital both increase sedation. Use Caution/Monitor.

• cyclobenzaprine

  Monitor Closely (1)butabarbital and cyclobenzaprine both increase sedation. Use Caution/Monitor.

• cyclophosphamide

  Monitor Closely (1)butabarbital will decrease the level or effect of cyclophosphamide by affecting hepatic enzyme CYP2B6 metabolism. Use Caution/Monitor.

• cyclosporine

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

• cyproheptadine

  Monitor Closely (1)cyproheptadine and butabarbital both increase sedation. Use Caution/Monitor.

• dalteparin

  Serious - Use Alternative (1)butabarbital decreases effects of dalteparin by increasing metabolism. Avoid or Use Alternate Drug.

• dantrolene

  Monitor Closely (1)butabarbital and dantrolene both increase sedation. Use Caution/Monitor.

• dapsone

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

• darifenacin

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

• darunavir

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

• dasatinib

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

• deflazacort

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of deflazacort by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of deflazacort with moderate or strong CYP3A4 inducers.

• desipramine

  Monitor Closely (2)butabarbital will decrease the level or effect of desipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.
  
  butabarbital and desipramine both increase sedation. Use Caution/Monitor.Minor (1)butabarbital, desipramine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• deutetrabenazine

  Monitor Closely (1)butabarbital and deutetrabenazine both increase sedation. Use Caution/Monitor.

• dexamethasone

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

• dexchlorpheniramine

  Monitor Closely (1)dexchlorpheniramine and butabarbital both increase sedation. Use Caution/Monitor.

• dexfenfluramine

  Monitor Closely (1)butabarbital increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dexmedetomidine

  Monitor Closely (1)butabarbital and dexmedetomidine both increase sedation. Use Caution/Monitor.

• dexmethylphenidate

  Monitor Closely (1)butabarbital increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dextroamphetamine

  Monitor Closely (1)butabarbital increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dextromoramide

  Monitor Closely (1)butabarbital and dextromoramide both increase sedation. Use Caution/Monitor.

• diamorphine

  Monitor Closely (1)butabarbital and diamorphine both increase sedation. Use Caution/Monitor.

• diazepam

  Monitor Closely (2)butabarbital will decrease the level or effect of diazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and diazepam both increase sedation. Use Caution/Monitor.

• diazepam intranasal

  Monitor Closely (2)butabarbital will decrease the level or effect of diazepam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong or moderate CYP3A4 inducers may increase rate of diazepam elimination; therefore, efficacy of diazepam may be decreased.
  
  diazepam intranasal, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may potentiate the CNS-depressant effects of each drug.

• diclofenac

  Minor (1)butabarbital will decrease the level or effect of diclofenac by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• diethylpropion

  Monitor Closely (1)butabarbital increases and diethylpropion decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• difenoxin hcl

  Monitor Closely (1)butabarbital and difenoxin hcl both increase sedation. Use Caution/Monitor.

• dihydroergotamine

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

• dihydroergotamine intranasal

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of dihydroergotamine intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• diltiazem

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

• dimenhydrinate

  Monitor Closely (1)dimenhydrinate and butabarbital both increase sedation. Use Caution/Monitor.

• diphenhydramine

  Monitor Closely (1)diphenhydramine and butabarbital both increase sedation. Use Caution/Monitor.

• diphenoxylate hcl

  Monitor Closely (1)butabarbital and diphenoxylate hcl both increase sedation. Use Caution/Monitor.

• dipipanone

  Monitor Closely (1)butabarbital and dipipanone both increase sedation. Use Caution/Monitor.

• disopyramide

  Minor (1)butabarbital will decrease the level or effect of disopyramide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• dobutamine

  Monitor Closely (1)butabarbital increases and dobutamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• docetaxel

  Minor (1)butabarbital will decrease the level or effect of docetaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• donepezil

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

• dopamine

  Monitor Closely (1)butabarbital increases and dopamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dopexamine

  Monitor Closely (1)butabarbital increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• doravirine

  Contraindicated (1)butabarbital will decrease the level or effect of doravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of doravirine with a strong CYP3A inducer may decrease doravirine plasma concentrations and/or effects. Potential for loss of virologic response and possible resistance to doravirine.

• dosulepin

  Monitor Closely (1)butabarbital and dosulepin both increase sedation. Use Caution/Monitor.Minor (1)butabarbital, dosulepin. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• doxepin

  Monitor Closely (1)butabarbital and doxepin both increase sedation. Use Caution/Monitor.Minor (1)butabarbital, doxepin. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• doxorubicin

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

• doxorubicin liposomal

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

• doxycycline

  Monitor Closely (1)butabarbital decreases levels of doxycycline by increasing metabolism. Use Caution/Monitor.

• doxylamine

  Monitor Closely (1)butabarbital and doxylamine both increase sedation. Use Caution/Monitor.

• dronabinol

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

• dronedarone

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

• droperidol

  Monitor Closely (1)butabarbital and droperidol both increase sedation. Use Caution/Monitor.

• duloxetine

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

• dutasteride

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

• duvelisib

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of duvelisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration with a strong CYP3A inducer decreases duvelisib area under the curve (AUC), which may reduce duvelisib efficacy.

• efavirenz

  Minor (1)butabarbital will decrease the level or effect of efavirenz by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• elagolix

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

• eletriptan

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

• eltrombopag

  Monitor Closely (2)butabarbital will decrease the level or effect of eltrombopag by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of eltrombopag by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

• enoxaparin

  Serious - Use Alternative (1)butabarbital decreases effects of enoxaparin by increasing metabolism. Avoid or Use Alternate Drug.

• ephedrine

  Monitor Closely (1)butabarbital increases and ephedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• epinephrine

  Monitor Closely (1)butabarbital increases and epinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• epinephrine racemic

  Monitor Closely (1)butabarbital increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• eplerenone

  Minor (1)butabarbital will decrease the level or effect of eplerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• erdafitinib

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

• ergotamine

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

• erlotinib

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

• erythromycin base

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of erythromycin base by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.Minor (1)butabarbital decreases levels of erythromycin base by increasing elimination. Minor/Significance Unknown.

• erythromycin ethylsuccinate

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of erythromycin ethylsuccinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.Minor (1)butabarbital decreases levels of erythromycin ethylsuccinate by increasing elimination. Minor/Significance Unknown.

• erythromycin lactobionate

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of erythromycin lactobionate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.Minor (1)butabarbital decreases levels of erythromycin lactobionate by increasing elimination. Minor/Significance Unknown.

• erythromycin stearate

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of erythromycin stearate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.Minor (1)butabarbital decreases levels of erythromycin stearate by increasing elimination. Minor/Significance Unknown.

• escitalopram

  Monitor Closely (1)butabarbital will decrease the level or effect of escitalopram by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• esketamine intranasal

  Monitor Closely (1)esketamine intranasal, butabarbital. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.

• esmolol

  Monitor Closely (1)butabarbital decreases levels of esmolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• esomeprazole

  Monitor Closely (1)butabarbital will decrease the level or effect of esomeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• estazolam

  Monitor Closely (1)butabarbital and estazolam both increase sedation. Use Caution/Monitor.

• estradiol

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

• estradiol vaginal

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

• estrogens conjugated synthetic

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

• estrogens esterified

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

• estropipate

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

• ethanol

  Monitor Closely (1)butabarbital and ethanol both increase sedation. Use Caution/Monitor.

• ethinylestradiol

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of ethinylestradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. The efficacy of hormonal contraceptives may be reduced. Use of a nonhormonal contraceptive is recommended.

• ethosuximide

  Minor (1)ethosuximide decreases effects of butabarbital by pharmacodynamic antagonism. Minor/Significance Unknown.

• ethotoin

  Monitor Closely (1)butabarbital will decrease the level or effect of ethotoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

• etomidate

  Monitor Closely (1)etomidate and butabarbital both increase sedation. Use Caution/Monitor.

• etonogestrel

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

• etoposide

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

• etravirine

  Monitor Closely (3)butabarbital will decrease the level or effect of etravirine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of etravirine by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of etravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• eucalyptus

  Minor (2)butabarbital will decrease the level or effect of eucalyptus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  butabarbital and eucalyptus both increase sedation. Minor/Significance Unknown.

• everolimus

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

• exemestane

  Monitor Closely (1)butabarbital will decrease the level or effect of exemestane by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. For patients receiving exemestane with a potent CYP3A4 inducer the recommended dose of exemestane is 50 mg daily after a meal.

• fedratinib

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• felodipine

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

• fenfluramine

  Monitor Closely (1)butabarbital increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• fentanyl

  Serious - Use Alternative (1)fentanyl, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl intranasal

  Serious - Use Alternative (1)fentanyl intranasal, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl transdermal

  Serious - Use Alternative (1)fentanyl transdermal, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl transmucosal

  Serious - Use Alternative (1)fentanyl transmucosal, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fesoterodine

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

• fexinidazole

  Serious - Use Alternative (1)butabarbital will increase the level or effect of fexinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. CYP450 inducers may significantly increase plasma concentrations of fexinidazole?s active metabolites: fexinidazole sulfoxide (M1) and fexinidazole sulfone (M2). M2 plasma concentrations associated with increased QT prolongation risks.

• finasteride

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

• finerenone

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

• flibanserin

  Monitor Closely (1)butabarbital and flibanserin both increase sedation. Modify Therapy/Monitor Closely. Risk for sedation increased if flibanserin is coadministration with other CNS depressants.

• fluconazole

  Minor (1)butabarbital decreases levels of fluconazole by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• fludrocortisone

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

• fluphenazine

  Monitor Closely (1)butabarbital and fluphenazine both increase sedation. Use Caution/Monitor.

• flurazepam

  Monitor Closely (1)butabarbital and flurazepam both increase sedation. Use Caution/Monitor.

• flurbiprofen

  Minor (1)butabarbital will decrease the level or effect of flurbiprofen by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• fondaparinux

  Serious - Use Alternative (1)butabarbital decreases effects of fondaparinux by increasing metabolism. Avoid or Use Alternate Drug.

• formoterol

  Monitor Closely (1)butabarbital increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• fosamprenavir

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

• fosphenytoin

  Monitor Closely (1)butabarbital will decrease the level or effect of fosphenytoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

• fostamatinib

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

• fostemsavir

  Contraindicated (1)butabarbital will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.

• frovatriptan

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

• gabapentin

  Monitor Closely (1)gabapentin, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.

• gabapentin enacarbil

  Monitor Closely (1)gabapentin enacarbil, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.

• galantamine

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

• glasdegib

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of glasdegib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of glasdegib with strong CYP3A inducers.

• glecaprevir/pibrentasvir

  Monitor Closely (1)butabarbital will decrease the level or effect of glecaprevir/pibrentasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of drugs that induce CYP3A4 with glecaprevir/pibrentasvir may decrease glecaprevir/pibrentasvir plasma concentrations. Potential for loss of therapeutic effect.

• gotu kola

  Monitor Closely (1)gotu kola increases effects of butabarbital by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.

• griseofulvin

  Minor (1)butabarbital decreases levels of griseofulvin by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• guanfacine

  Monitor Closely (1)butabarbital will decrease the level or effect of guanfacine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong or moderate CYP3A4 inducers significantly reduce guanfacine plasma concentrations and elimination half-life. If coadministered, more frequent dosing of the IR product may be required to achieve or maintain the desired hypotensive response. For patients with ADHD, FDA-approved labeling for ER guanfacine recommends that, if coadministered, doubling the recommended dose of guanfacine should be considered.

• haloperidol

  Monitor Closely (1)butabarbital and haloperidol both increase sedation. Use Caution/Monitor.Minor (1)haloperidol, butabarbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hyperthermia if haloperidol admin. during barbiturate withdrawal.

• hawthorn

  Monitor Closely (1)hawthorn increases effects of butabarbital by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.

• hemin

  Monitor Closely (1)butabarbital decreases effects of hemin by pharmacodynamic antagonism. Use Caution/Monitor. Drugs that increase delta-aminolevulinic acid synthetase may decrease hemin effect.

• heparin

  Serious - Use Alternative (1)butabarbital decreases effects of heparin by increasing metabolism. Avoid or Use Alternate Drug.

• hops

  Monitor Closely (1)hops increases effects of butabarbital by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.

• hydrocodone

  Serious - Use Alternative (1)hydrocodone, butabarbital. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• hydrocortisone

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

• hydromorphone

  Monitor Closely (1)butabarbital and hydromorphone both increase sedation. Use Caution/Monitor.

• hydroxyprogesterone caproate

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

• hydroxyzine

  Monitor Closely (1)hydroxyzine and butabarbital both increase sedation. Use Caution/Monitor.

• ibuprofen

  Minor (1)butabarbital will decrease the level or effect of ibuprofen by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• ibuprofen IV

  Minor (1)butabarbital will decrease the level or effect of ibuprofen IV by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• ifosfamide

  Monitor Closely (2)butabarbital increases effects of ifosfamide by affecting hepatic enzyme CYP2B6 metabolism. Use Caution/Monitor. Coadministration of ifosfamide with CYP2B6 inducers may increase metabolism of ifosfamide to its metabolite. Monitor for increased effects/toxicities if combined with CYP2B6 inducers.
  
  butabarbital increases effects of ifosfamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers may increase the metabolism of ifosfamide to its active alkylating metabolites. CYP3A4 inducers may increase the formation of the neurotoxic/nephrotoxic ifosfamide metabolite, chloroacetaldehyde. Closely monitor patients taking ifosfamide with CYP3A4 inducers for toxicities and consider dose adjustment.

• iloperidone

  Monitor Closely (2)butabarbital will decrease the level or effect of iloperidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and iloperidone both increase sedation. Use Caution/Monitor.

• imatinib

  Minor (1)butabarbital will decrease the level or effect of imatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• imipramine

  Monitor Closely (4)butabarbital will decrease the level or effect of imipramine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of imipramine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of imipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.
  
  butabarbital and imipramine both increase sedation. Use Caution/Monitor.Minor (1)butabarbital, imipramine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• indinavir

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

• infigratinib

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

• isocarboxazid

  Serious - Use Alternative (1)isocarboxazid, butabarbital. Other (see comment). Contraindicated. Comment: CNS depressants such as barbiturates should not be used in combination with isocarboxazid.Minor (1)isocarboxazid increases levels of butabarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.

• isoproterenol

  Monitor Closely (1)butabarbital increases and isoproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• isradipine

  Minor (1)butabarbital will decrease the level or effect of isradipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• istradefylline

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of istradefylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of istradefylline with strong CYP3A4 inducers.

• ivosidenib

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of ivosidenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of ivosidenib with strong CYP3A4 inducers decreased ivosidenib plasma concentrations.

• ixabepilone

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

• kava

  Monitor Closely (1)kava increases effects of butabarbital by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.

• ketamine

  Monitor Closely (1)ketamine and butabarbital both increase sedation. Use Caution/Monitor.

• ketoconazole

  Minor (2)butabarbital will decrease the level or effect of ketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  butabarbital decreases levels of ketoconazole by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• ketotifen, ophthalmic

  Monitor Closely (1)butabarbital and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.

• labetalol

  Monitor Closely (1)butabarbital decreases levels of labetalol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• lansoprazole

  Minor (1)butabarbital will decrease the level or effect of lansoprazole by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• lapatinib

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

• larotrectinib

  Serious - Use Alternative (1)butabarbital will increase the level or effect of larotrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of larotrectinib with strong CYP3A4 inducers is unavoidable, double larotrectinib dose. Resume prior larotrectinib dose once CYP3A4 inducer discontinued for 3-5 half-lives.

• lasmiditan

  Monitor Closely (1)lasmiditan, butabarbital. Either increases effects of the other by sedation. Use Caution/Monitor. Coadministration of lasmiditan and other CNS depressant drugs, including alcohol have not been evaluated in clinical studies. Lasmiditan may cause sedation, as well as other cognitive and/or neuropsychiatric adverse reactions.

• lefamulin

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of lefamulin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of lefamulin with strong or moderate CYP3A inducers unless the benefit outweighs risks. Monitor for reduced efficacy.

• lemborexant

  Serious - Use Alternative (2)butabarbital will decrease the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  lemborexant, butabarbital. Either increases effects of the other by sedation. Avoid or Use Alternate Drug. Use of lemborexant with other drugs to treat insomnia is not recommended.

• levalbuterol

  Monitor Closely (1)butabarbital increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• levamlodipine

  Monitor Closely (1)butabarbital will decrease the level or effect of levamlodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No information is available on the quantitative effects of CYP3A4 inducers on amlodipine. Closely monitor blood pressure when amlodipine is coadministered with CYP3A4 inducers.

• levonorgestrel oral/ethinylestradiol/ferrous bisglycinate

  Monitor Closely (1)butabarbital will decrease the level or effect of levonorgestrel oral/ethinylestradiol/ferrous bisglycinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. The efficacy of hormonal contraceptives may be reduced. Use an alternative method of contraception or a backup method when enzyme inducers are used with combined hormonal contraceptives (CHCs), and continue backup contraception for 28 days after discontinuing enzyme inducer to ensure contraceptive reliability.

• levorphanol

  Monitor Closely (1)butabarbital and levorphanol both increase sedation. Use Caution/Monitor.

• levothyroxine

  Minor (1)butabarbital decreases levels of levothyroxine by increasing metabolism. Minor/Significance Unknown.

• lidocaine

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

• linezolid

  Minor (1)linezolid increases levels of butabarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.

• liothyronine

  Minor (1)butabarbital decreases levels of liothyronine by increasing metabolism. Minor/Significance Unknown.

• lisdexamfetamine

  Monitor Closely (1)butabarbital increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• lofepramine

  Monitor Closely (1)butabarbital and lofepramine both increase sedation. Use Caution/Monitor.Minor (1)butabarbital, lofepramine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• lofexidine

  Monitor Closely (1)butabarbital and lofexidine both increase sedation. Use Caution/Monitor.

• lonafarnib

  Contraindicated (1)butabarbital will decrease 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 inducers is contraindicated.

• lopinavir

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

• loprazolam

  Monitor Closely (1)butabarbital and loprazolam both increase sedation. Use Caution/Monitor.

• loratadine

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

• lorazepam

  Monitor Closely (1)butabarbital and lorazepam both increase sedation. Use Caution/Monitor.

• lorlatinib

  Contraindicated (1)butabarbital will decrease the level or effect of lorlatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of lorlatinib with strong CYP3A inducers is contraindicated. Discontinue the strong CYP3A inducer for 3 plasma half-lives before initiating lorlatinib.

• lormetazepam

  Monitor Closely (1)butabarbital and lormetazepam both increase sedation. Use Caution/Monitor.

• losartan

  Minor (1)butabarbital will decrease the level or effect of losartan by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• lovastatin

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

• loxapine

  Monitor Closely (1)butabarbital and loxapine both increase sedation. Use Caution/Monitor.

• loxapine inhaled

  Monitor Closely (1)butabarbital and loxapine inhaled both increase sedation. Use Caution/Monitor.

• lumefantrine

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

• lurasidone

  Monitor Closely (1)lurasidone, butabarbital. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Potential for increased CNS depressant effects when used concurrently; monitor for increased adverse effects and toxicity.

• lurbinectedin

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

• maprotiline

  Monitor Closely (1)butabarbital and maprotiline both increase sedation. Use Caution/Monitor.Minor (1)butabarbital, maprotiline. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• maraviroc

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

• marijuana

  Monitor Closely (1)butabarbital and marijuana both increase sedation. Use Caution/Monitor.

• melatonin

  Monitor Closely (1)butabarbital and melatonin both increase sedation. Use Caution/Monitor.

• meloxicam

  Minor (1)butabarbital will decrease the level or effect of meloxicam by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• meperidine

  Monitor Closely (1)butabarbital and meperidine both increase sedation. Use Caution/Monitor.

• meprobamate

  Monitor Closely (1)butabarbital and meprobamate both increase sedation. Use Caution/Monitor.

• mestranol

  Monitor Closely (1)butabarbital will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)butabarbital decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. May result in contraceptive failure.

• metaproterenol

  Monitor Closely (1)butabarbital increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• metaxalone

  Monitor Closely (1)butabarbital and metaxalone both increase sedation. Use Caution/Monitor.

• methadone

  Monitor Closely (2)butabarbital will decrease the level or effect of methadone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and methadone both increase sedation. Use Caution/Monitor.

• methamphetamine

  Monitor Closely (1)butabarbital increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• methazolamide

  Minor (1)methazolamide, butabarbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Increased risk of anticonvulsant induced osteomalacia.

• methocarbamol

  Monitor Closely (1)butabarbital and methocarbamol both increase sedation. Use Caution/Monitor.

• methoxyflurane

  Serious - Use Alternative (1)butabarbital increases toxicity of methoxyflurane by increasing metabolism. Contraindicated. Increased metabolism of methoxyflurane to nephrotoxic compounds.

• methsuximide

  Minor (1)methsuximide decreases effects of butabarbital by pharmacodynamic antagonism. Minor/Significance Unknown.

• methylenedioxymethamphetamine

  Monitor Closely (1)butabarbital increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• methylprednisolone

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

• metoprolol

  Monitor Closely (1)butabarbital decreases levels of metoprolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• mexiletine

  Monitor Closely (1)butabarbital will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• miconazole vaginal

  Minor (1)butabarbital decreases levels of miconazole vaginal by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• midazolam

  Monitor Closely (2)butabarbital will decrease the level or effect of midazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and midazolam both increase sedation. Use Caution/Monitor.

• midazolam intranasal

  Monitor Closely (1)midazolam intranasal, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase the risk of hypoventilation, airway obstruction, desaturation, or apnea and may contribute to profound and/or prolonged drug effect.

• midodrine

  Monitor Closely (1)butabarbital increases and midodrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• midostaurin

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of midostaurin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Strong CYP3A4 inducers may decrease midostaurin concentrations resulting in reduced efficacy.

• mirtazapine

  Monitor Closely (1)butabarbital and mirtazapine both increase sedation. Use Caution/Monitor.

• mobocertinib

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

• modafinil

  Monitor Closely (1)butabarbital increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• montelukast

  Minor (1)butabarbital will decrease the level or effect of montelukast by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• morphine

  Monitor Closely (1)butabarbital and morphine both increase sedation. Use Caution/Monitor.

• motherwort

  Monitor Closely (1)butabarbital and motherwort both increase sedation. Use Caution/Monitor.

• moxonidine

  Monitor Closely (1)butabarbital and moxonidine both increase sedation. Use Caution/Monitor.

• nabilone

  Monitor Closely (1)butabarbital and nabilone both increase sedation. Use Caution/Monitor.

• nadolol

  Monitor Closely (1)butabarbital decreases levels of nadolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• nalbuphine

  Monitor Closely (1)butabarbital and nalbuphine both increase sedation. Use Caution/Monitor.

• naldemedine

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of naldemedine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with strong CYP3A4 inducers.

• nateglinide

  Monitor Closely (1)butabarbital will decrease the level or effect of nateglinide by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

• nebivolol

  Monitor Closely (1)butabarbital decreases levels of nebivolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• nelfinavir

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

• neratinib

  Serious - Use Alternative (1)butabarbital will decrease 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 inducers.

• nettle

  Minor (1)nettle increases effects of butabarbital by pharmacodynamic synergism. Minor/Significance Unknown. (High dose nettle; theoretical interaction) May enhance CNS depression.

• nicardipine

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

• nifedipine

  Minor (1)butabarbital will decrease the level or effect of nifedipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• nilotinib

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

• nimodipine

  Minor (1)butabarbital will decrease the level or effect of nimodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• nisoldipine

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

• nitrendipine

  Minor (1)butabarbital will decrease the level or effect of nitrendipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• norepinephrine

  Monitor Closely (1)butabarbital increases and norepinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• nortriptyline

  Monitor Closely (1)butabarbital and nortriptyline both increase sedation. Use Caution/Monitor.Minor (1)butabarbital, nortriptyline. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• olanzapine

  Monitor Closely (2)butabarbital will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  butabarbital and olanzapine both increase sedation. Use Caution/Monitor.

• oliceridine

  Monitor Closely (2)butabarbital will decrease the level or effect of oliceridine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. If coadministration with a CYP3A4 inducer is necessary, consider increasing oliceridine dose until stable drug effects are achieved; monitor for signs of opioid withdrawal. If inducer is discontinued, consider oliceridine dosage reduction and monitor for signs of respiratory depression.
  
  oliceridine, butabarbital. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• omeprazole

  Monitor Closely (1)butabarbital will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• ondansetron

  Monitor Closely (1)butabarbital will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment for ondansetron is recommended for patients on these drugs.Minor (1)butabarbital will decrease the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• opium tincture

  Monitor Closely (1)butabarbital and opium tincture both increase sedation. Use Caution/Monitor.

• orphenadrine

  Monitor Closely (1)butabarbital and orphenadrine both increase sedation. Use Caution/Monitor.

• osilodrostat

  Monitor Closely (1)butabarbital will decrease the level or effect of osilodrostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor cortisol concentration and patient?s signs and symptoms during coadministration or discontinuation with strong CYP3A4 inducers. Adjust dose of osilodrostat if necessary.

• oxazepam

  Monitor Closely (1)butabarbital and oxazepam both increase sedation. Use Caution/Monitor.

• oxybutynin

  Minor (1)butabarbital will decrease the level or effect of oxybutynin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• oxycodone

  Monitor Closely (1)butabarbital and oxycodone both increase sedation. Use Caution/Monitor.

• oxymorphone

  Monitor Closely (1)butabarbital and oxymorphone both increase sedation. Use Caution/Monitor.

• paclitaxel

  Minor (1)butabarbital will decrease the level or effect of paclitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• paclitaxel protein bound

  Minor (1)butabarbital will decrease the level or effect of paclitaxel protein bound by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• paliperidone

  Monitor Closely (1)butabarbital and paliperidone both increase sedation. Use Caution/Monitor.

• pantoprazole

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

• papaveretum

  Monitor Closely (1)butabarbital and papaveretum both increase sedation. Use Caution/Monitor.

• papaverine

  Monitor Closely (1)butabarbital and papaverine both increase sedation. Use Caution/Monitor.

• parecoxib

  Monitor Closely (1)butabarbital will decrease the level or effect of parecoxib by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.Minor (1)butabarbital will decrease the level or effect of parecoxib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• passion flower

  Monitor Closely (1)passion flower increases effects of butabarbital by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.

• pazopanib

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

• pemigatinib

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

• penbutolol

  Monitor Closely (1)butabarbital decreases levels of penbutolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• pentazocine

  Monitor Closely (1)butabarbital and pentazocine both increase sedation. Use Caution/Monitor.

• pentobarbital

  Monitor Closely (1)butabarbital and pentobarbital both increase sedation. Use Caution/Monitor.

• perphenazine

  Monitor Closely (1)butabarbital and perphenazine both increase sedation. Use Caution/Monitor.

• pexidartinib

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

• phendimetrazine

  Monitor Closely (1)butabarbital increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• phenelzine

  Minor (1)phenelzine increases levels of butabarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.

• phenindione

  Serious - Use Alternative (1)butabarbital decreases effects of phenindione by increasing metabolism. Avoid or Use Alternate Drug.

• phenobarbital

  Monitor Closely (1)butabarbital and phenobarbital both increase sedation. Use Caution/Monitor.

• phentermine

  Monitor Closely (1)butabarbital increases and phentermine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• phenylephrine

  Monitor Closely (1)butabarbital increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• phenylephrine PO

  Monitor Closely (1)butabarbital increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .

• phenytoin

  Monitor Closely (1)butabarbital will decrease the level or effect of phenytoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

• pholcodine

  Monitor Closely (1)butabarbital and pholcodine both increase sedation. Use Caution/Monitor.

• pimozide

  Monitor Closely (1)butabarbital and pimozide both increase sedation. Use Caution/Monitor.Minor (1)butabarbital will decrease the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• pindolol

  Monitor Closely (1)butabarbital decreases levels of pindolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• pioglitazone

  Minor (1)butabarbital will decrease the level or effect of pioglitazone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• pirbuterol

  Monitor Closely (1)butabarbital increases and pirbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• piroxicam

  Minor (1)butabarbital will decrease the level or effect of piroxicam by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• pitolisant

  Monitor Closely (1)butabarbital will decrease the level or effect of pitolisant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Pitolisant exposure is decreased by 50% if coadministered with strong CYP3A4 inducers. For patients stable on pitolisant 8.9 mg/day or 17.8 mg/day, double the pitolisant dose (ie, 17.8 mg or 35.6 mg, respectively) over 7 days. If the strong CYP3A4 inducer is discontinued, reduce pitolisant dosage by half.

• polatuzumab vedotin

  Monitor Closely (1)butabarbital will decrease the level or effect of polatuzumab vedotin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Polatuzumab undergoes catabolism to small peptides, amino acids, monomethyl auristatin E (MMAE), and unconjugated MMAE-related catabolites. MMAE is a CYP3A4 substrate. Coadministration of polatuzumab vedotin with a strong CYP3A4 inducer may decrease unconjugated MMAE AUC.

• posaconazole

  Minor (1)butabarbital decreases levels of posaconazole by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• pralsetinib

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of pralsetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid, double current pralsetinib dose starting on Day 7 of coadministration with strong CYP3A inducer. After inducer has been discontinued for at least 14 days, resume previous pralsetinib dose.

• prednisolone

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

• prednisone

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

• pregabalin

  Monitor Closely (1)pregabalin, butabarbital. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.

• pretomanid

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of pretomanid by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Pretomanid is a CYP3A4 substrate. Avoid coadministration of strong or moderate CYP3A4 inducers.

• primidone

  Monitor Closely (1)butabarbital and primidone both increase sedation. Use Caution/Monitor.

• procarbazine

  Minor (1)procarbazine increases levels of butabarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.

• prochlorperazine

  Monitor Closely (1)butabarbital and prochlorperazine both increase sedation. Use Caution/Monitor.

• promethazine

  Monitor Closely (1)promethazine and butabarbital both increase sedation. Use Caution/Monitor.

• propafenone

  Monitor Closely (1)butabarbital decreases levels of propafenone by increasing metabolism. Use Caution/Monitor.Minor (1)butabarbital will decrease the level or effect of propafenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• propofol

  Monitor Closely (1)propofol and butabarbital both increase sedation. Use Caution/Monitor.

• propranolol

  Monitor Closely (1)butabarbital decreases levels of propranolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• propylhexedrine

  Monitor Closely (1)butabarbital increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• protamine

  Serious - Use Alternative (1)butabarbital decreases effects of protamine by increasing metabolism. Avoid or Use Alternate Drug.

• protriptyline

  Monitor Closely (1)butabarbital and protriptyline both increase sedation. Use Caution/Monitor.Minor (1)butabarbital, protriptyline. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• quazepam

  Monitor Closely (1)butabarbital and quazepam both increase sedation. Use Caution/Monitor.

• quetiapine

  Monitor Closely (2)butabarbital will decrease the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and quetiapine both increase sedation. Use Caution/Monitor.

• quinidine

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

• quinine

  Minor (1)butabarbital will decrease the level or effect of quinine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• rabeprazole

  Minor (2)butabarbital will decrease the level or effect of rabeprazole by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.
  
  butabarbital will decrease the level or effect of rabeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ramelteon

  Monitor Closely (2)butabarbital will decrease the level or effect of ramelteon by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  butabarbital and ramelteon both increase sedation. Use Caution/Monitor.Minor (2)butabarbital will decrease the level or effect of ramelteon by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
  
  butabarbital will decrease the level or effect of ramelteon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ranolazine

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

• remimazolam

  Monitor Closely (1)remimazolam, butabarbital. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely. Coadministration may result in profound sedation, respiratory depression, coma, and/or death. Continuously monitor vital signs during sedation and recovery period if coadministered. Carefully titrate remimazolam dose if administered with opioid analgesics and/or sedative/hypnotics.

• repaglinide

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

• rifampin

  Monitor Closely (1)rifampin decreases levels of butabarbital by increasing metabolism. Use Caution/Monitor.

• riluzole

  Minor (1)butabarbital will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• rimegepant

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

• risperidone

  Monitor Closely (1)butabarbital and risperidone both increase sedation. Use Caution/Monitor.

• ritonavir

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

• romidepsin

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

• rose hips

  Minor (1)butabarbital decreases levels of rose hips by increasing elimination. Minor/Significance Unknown.

• sage

  Minor (1)butabarbital and sage both increase sedation. Minor/Significance Unknown.

• salmeterol

  Monitor Closely (1)butabarbital increases and salmeterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• saquinavir

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

• saxagliptin

  Minor (1)butabarbital will decrease the level or effect of saxagliptin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• scullcap

  Monitor Closely (1)butabarbital and scullcap both increase sedation. Use Caution/Monitor.

• secobarbital

  Monitor Closely (1)butabarbital and secobarbital both increase sedation. Use Caution/Monitor.

• selegiline transdermal

  Minor (1)selegiline transdermal increases levels of butabarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.

• selinexor

  Serious - Use Alternative (1)selinexor, butabarbital. unspecified interaction mechanism. Avoid or Use Alternate Drug. Patients treated with selinexor may experience neurological toxicities. Avoid taking selinexor with other medications that may cause dizziness or confusion.

• selumetinib

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

• shepherd's purse

  Monitor Closely (1)butabarbital and shepherd's purse both increase sedation. Use Caution/Monitor.

• Siberian ginseng

  Minor (1)Siberian ginseng increases effects of butabarbital by pharmacodynamic synergism. Minor/Significance Unknown. May enhance CNS depression.

• sildenafil

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

• silodosin

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

• simvastatin

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

• siponimod

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• sirolimus

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

• sodium oxybate

  Contraindicated (1)butabarbital, sodium oxybate. Either increases effects of the other by pharmacodynamic synergism. Contraindicated. Coadministration with alcohol or sedative hypnotics are contraindicated because of additive CNS depression.

• solifenacin

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

• sorafenib

  Monitor Closely (1)butabarbital decreases levels of sorafenib by increasing metabolism. Use Caution/Monitor.

• sotalol

  Monitor Closely (1)butabarbital decreases levels of sotalol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• sotorasib

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

• stiripentol

  Serious - Use Alternative (2)butabarbital will decrease the level or effect of stiripentol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration of stiripentol with strong CYP3A4 inducers, increase stiripentol dose.
  
  stiripentol, butabarbital. Either increases effects of the other by sedation. Avoid or Use Alternate Drug. Concomitant use stiripentol with other CNS depressants, including alcohol, may increase the risk of sedation and somnolence.

• sufentanil

  Monitor Closely (1)butabarbital and sufentanil both increase sedation. Use Caution/Monitor.Minor (1)butabarbital will decrease the level or effect of sufentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• sufentanil SL

  Monitor Closely (1)butabarbital decreases effects of sufentanil SL by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration of CYP3A4 inducers may decrease sufentanil levels and efficacy, possibly precipitating withdrawal syndrome in patients who have developed physical dependence to sufentanil. Discontinuation of concomitantly used CYP3A4 inducers may increase sufentanil plasma concentration.Serious - Use Alternative (1)sufentanil SL, butabarbital. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration may result in hypotension, profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• sulfamethoxazole

  Minor (1)butabarbital will decrease the level or effect of sulfamethoxazole by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• sunitinib

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

• tacrolimus

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

• tadalafil

  Monitor Closely (1)butabarbital will decrease the level or effect of tadalafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Avoid combination in pulmonary HTN patients. For patients with ED, monitor response to tadalafil carefully because of potential for decreased effectiveness.

• tamoxifen

  Monitor Closely (2)butabarbital will decrease the level or effect of tamoxifen by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of tamoxifen by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tapentadol

  Monitor Closely (1)butabarbital and tapentadol both increase sedation. Use Caution/Monitor.

• tazemetostat

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

• temazepam

  Monitor Closely (1)butabarbital and temazepam both increase sedation. Use Caution/Monitor.

• temsirolimus

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

• tepotinib

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

• terbinafine

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

• terbutaline

  Monitor Closely (1)butabarbital increases and terbutaline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• tezacaftor

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

• thalidomide

  Monitor Closely (1)thalidomide increases effects of butabarbital by unspecified interaction mechanism. Use Caution/Monitor. Increased sedative effects.

• theophylline

  Monitor Closely (2)butabarbital will decrease the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• thioridazine

  Monitor Closely (1)butabarbital and thioridazine both increase sedation. Use Caution/Monitor.Minor (1)thioridazine decreases levels of butabarbital by unspecified interaction mechanism. Minor/Significance Unknown.

• thiothixene

  Monitor Closely (1)butabarbital and thiothixene both increase sedation. Use Caution/Monitor.

• thyroid desiccated

  Minor (1)butabarbital decreases levels of thyroid desiccated by increasing metabolism. Minor/Significance Unknown.

• tibolone

  Minor (1)butabarbital decreases levels of tibolone by increasing metabolism. Minor/Significance Unknown. Theoretical interaction.

• timolol

  Monitor Closely (1)butabarbital decreases levels of timolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• tinidazole

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

• tipranavir

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

• tivozanib

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

• tizanidine

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of tizanidine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug.

• tolbutamide

  Minor (1)butabarbital will decrease the level or effect of tolbutamide by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• tolterodine

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

• tolvaptan

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

• topiramate

  Monitor Closely (1)butabarbital and topiramate both increase sedation. Modify Therapy/Monitor Closely.Minor (1)butabarbital decreases levels of topiramate by increasing metabolism. Minor/Significance Unknown.

• tramadol

  Monitor Closely (1)butabarbital and tramadol both increase sedation. Use Caution/Monitor.

• tranylcypromine

  Minor (1)tranylcypromine increases levels of butabarbital by decreasing metabolism. Minor/Significance Unknown. Theoretical interaction.

• trazodone

  Monitor Closely (2)butabarbital will decrease the level or effect of trazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and trazodone both increase sedation. Use Caution/Monitor.Minor (1)butabarbital, trazodone. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• triamcinolone acetonide injectable suspension

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

• triazolam

  Monitor Closely (2)butabarbital will decrease the level or effect of triazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  butabarbital and triazolam both increase sedation. Use Caution/Monitor.

• triclofos

  Monitor Closely (1)butabarbital and triclofos both increase sedation. Use Caution/Monitor.

• trifluoperazine

  Monitor Closely (1)butabarbital and trifluoperazine both increase sedation. Use Caution/Monitor.

• trimipramine

  Monitor Closely (1)butabarbital and trimipramine both increase sedation. Use Caution/Monitor.Minor (1)butabarbital, trimipramine. Other (see comment). Minor/Significance Unknown. Comment: Barbiturates may increase adverse effects, including respiratory depression, produced by toxic doses of TCAs. With therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood concentrations of TCAs.

• triprolidine

  Monitor Closely (1)triprolidine and butabarbital both increase sedation. Use Caution/Monitor.

• tucatinib

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

• ubrogepant

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

• upadacitinib

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

• valerian

  Serious - Use Alternative (2)valerian increases effects of butabarbital by pharmacodynamic synergism. Avoid or Use Alternate Drug. May enhance CNS depression.
  
  valerian and butabarbital both increase sedation. Avoid or Use Alternate Drug.

• vardenafil

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

• verapamil

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

• vinblastine

  Minor (1)butabarbital will decrease the level or effect of vinblastine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• vincristine

  Minor (1)butabarbital will decrease the level or effect of vincristine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• vincristine liposomal

  Minor (1)butabarbital will decrease the level or effect of vincristine liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• vinorelbine

  Minor (1)butabarbital will decrease the level or effect of vinorelbine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• voclosporin

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

• voriconazole

  Serious - Use Alternative (1)butabarbital decreases levels of voriconazole by increasing metabolism. Contraindicated.Minor (2)butabarbital will decrease the level or effect of voriconazole by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.
  
  butabarbital will decrease the level or effect of voriconazole by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• voxelotor

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of voxelotor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor is primarily metabolized by CYP3A4. Avoid coadministration with moderate or strong CYP3A4 inducers. If unable to avoid coadministration, increase voxelotor dose (see Dosage Modifications).

• warfarin

  Monitor Closely (3)butabarbital will decrease the level or effect of warfarin by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of warfarin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
  
  butabarbital will decrease the level or effect of warfarin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)butabarbital decreases effects of warfarin by increasing metabolism. Avoid or Use Alternate Drug.Minor (1)butabarbital will decrease the level or effect of warfarin by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• xylometazoline

  Monitor Closely (1)butabarbital increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• yohimbine

  Monitor Closely (1)butabarbital increases and yohimbine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• zaleplon

  Minor (1)butabarbital will decrease the level or effect of zaleplon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• zanubrutinib

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

• ziconotide

  Monitor Closely (1)butabarbital and ziconotide both increase sedation. Use Caution/Monitor.

• ziprasidone

  Monitor Closely (1)butabarbital and ziprasidone both increase sedation. Use Caution/Monitor.Minor (1)butabarbital will decrease the level or effect of ziprasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• zolpidem

  Minor (1)butabarbital will decrease the level or effect of zolpidem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• zonisamide

  Minor (1)butabarbital will decrease the level or effect of zonisamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• zotepine

  Monitor Closely (1)butabarbital and zotepine both increase sedation. Use Caution/Monitor.