venlafaxine (Rx)

Major Depressive Disorder

Indicated for treatment of major depressive disorder (MDD)

Immediate-release tablets

• 75 mg/day PO divided q8-12hr initially; may be increased by ≤75 mg/day not faster than every 4 days
• Moderate: Up to 225 mg/day PO divided q8-12hr
• Severe: Up to 375 mg/day PO divided q8-12hr

Extended-release tablets or capsules (HCl salt)

• 37.5-75 mg PO once daily initially; may be increased by 75 mg/day every 4 days; not to exceed 225 mg/day

Extended-release tablets (besylate salt)

• Do not initiate treatment with venlafaxine besylate extended-release tablets
• Use another venlafaxine extended-release product for initial dosage, titration, and dosages below 112.5 mg qDay
• Can be initiated at 112.5 mg PO qDay in patients who have received >75 mg of another venlafaxine extended-release product for at least 4 days
• Not to exceed 225 mg/day

Generalized Anxiety Disorder

Indicated for treatment of generalized anxiety disorder (GAD)

Extended-release tablets or capsules (HCl salt) 37.5-75 mg PO once daily initially; may be increased by 75 mg/day every 4-7 days; not to exceed 225 mg/day

Extended-release tablets (besylate salt)

• Do not initiate treatment with venlafaxine besylate extended-release tablets
• Use another venlafaxine extended-release product for initial dosage, titration, and dosages below 112.5 mg qDay
• Can be initiated at 112.5 mg PO qDay in patients who have received >75 mg of another venlafaxine extended-release product for at least 4 days
• Not to exceed 225 mg/day

Social Anxiety Disorder

Indicated for treatment of social anxiety disorder (SAD)

Extended-release tablets or capsules (HCl salt): 75 mg PO once daily

Dosages >75 mg/day not shown to be more effective

Panic Disorder

Indicated for treatment of panic disorder, with or without agoraphobia

Extended-release tablets or capsules (HCl salt): 37.5 mg PO once daily for 7 days, then 75 mg once daily; may be further increased by 75 mg/day every 7 days; not to exceed 225 mg/day

Dosage Modifications

Renal impairment

• Mild or moderate (CrCl 30-89 mL/min): Decrease total daily dose (TDD) by 25-50%
• Severe (CrCl <30 mL/min or hemodialysis: Decrease TDD by 50% or more
• Extended-release tablets should not exceed 112.5 mg in patients with renal impairment; if TDD is <112.5 mg/day use another venlafaxine extended-release product

Hepatic impairment

• Mild-to-moderate (Child-Pugh 5-9): Decrease TDD by 50%
• Severe (Child-Pugh 10-15) or cirrhosis: Owing to individual variability in clearance, it may be necessary to reduce dose by 50% or more
• Extended-release tablets should not exceed 112.5 mg in patients with hepatic impairment; if TDD is <112.5 mg/day use another venlafaxine extended-release product

Hot Flashes Due to Hormonal Chemotherapy (Off-label)

Immediate-release: 37.5 mg BID or 75 mg qDay; alternatively may titrate up beginning with 37.5 mg qDay for 1 week then 75 mg daily

Extended-release: 37.5-150 mg PO once daily for 4-12 weeks

Post-traumatic Stress Disorder (Off-label)

Extended-release formulation: 37.5-300 mg/day

Attention Deficit Disorder (Off-label)

18.75-75 mg/day; may increase to 150 mg/day after 4 weeks; doses up to 225 mg/day used

Neuropathic Pain (Off-label)

75-225 mg/day PO ; onset of relief may start in 1-2 weeks or take up to 6 weeks for full benefit

Anxiety (Off-label)

Children: 37.5 mg/day PO initially

Adolescents: 37.5-75 mg/day PO initially

Maintenance: Children, 75-150 mg/day; adolescents, 150-300 mg/day

Depression (Off-label)

Children: 37.5 mg/day PO initially

Adolescents: 37.5-75 mg/day PO initially

Maintenance: Children, 75-150 mg/day; adolescents, 150-300 mg/day

Attention Deficit Disorder (Off-label)

<40 kg: 12.5 mg/day PO initially; increase by 12.5 mg/week; not to exceed 50 mg/day divided twice daily

≥40 kg: 12.5 mg/day PO initially; increase by 25 mg/week; not to exceed 75 mg/day divided three times daily

Major Depressive Disorder

Indicated for treatment of major depressive disorder (MDD)

Immediate-release tablets: 25-50 mg/day PO divided q8-12hr initially; may be increased as tolerated by ≤25 mg/day no faster than every 4 days

Extended-release tablets or capsules (HCl salt): 37.5 mg PO once daily initially; may be increased by 37.5 mg/day every 4-7 days; not to exceed 225 mg/day

Extended-release tablets (besylate salt)

• Do not initiate treatment with venlafaxine besylate extended-release tablets
• Use another venlafaxine extended-release product for initial dosage, titration, and dosages below 112.5 mg qDay
• Can be initiated at 112.5 mg PO qDay in patients who have received >75 mg of another venlafaxine extended-release product for at least 4 days
• Not to exceed 225 mg/day

Generalized Anxiety Disorder

Indicated for treatment of generalized anxiety disorder (GAD)

Extended-release tablets or capsules (HCl salt): 37.5 mg PO once daily initially; may be increased by 37.5 mg/day every 4 days; not to exceed 225 mg/day

Extended-release tablets (besylate salt)

• Do not initiate treatment with venlafaxine besylate extended-release tablets
• Use another venlafaxine extended-release product for initial dosage, titration, and dosages below 112.5 mg qDay
• Can be initiated at 112.5 mg PO qDay in patients who have received >75 mg of another venlafaxine extended-release product for at least 4 days
• Not to exceed 225 mg/day

Social Anxiety Disorder

Indicated for treatment of social anxiety disorder (SAD)

Extended-release tablets or capsules (HCl salt): 37.5 mg PO once daily; may be increased by 37.5 mg/day every 4 days

Panic Disorder

Indicated for treatment of panic disorder, with or without agoraphobia

Extended-release tablets or capsules (HCl salt): 37.5 mg PO once daily for 7 days, then 75 mg once daily; may be further increased by 37.5 mg/day every 7 days; not to exceed 225 mg/day

Dosage Modifications

Renal impairment

• Mild or moderate (CrCl 30-89 mL/min): Decrease total daily dose by 25-50%
• Severe (CrCl <30 mL/min or hemodialysis: Decrease total daily dose by 50% or more
• Extended-release tablets should not exceed 112.5 mg in patients with renal impairment; if TDD is <112.5 mg/day use another venlafaxine extended-release product

Hepatic impairment

• Mild-to-moderate (Child-Pugh 5-9): Decrease total daily dose by 50%
• Severe (Child-Pugh 10-15) or cirrhosis: Owing to individual variability in clearance, it may be necessary to reduce dose by 50% or more
• Extended-release tablets should not exceed 112.5 mg in patients with hepatic impairment; if TDD is <112.5 mg/day use another venlafaxine extended-release product

Contraindicated (8)

• iobenguane I 123

  venlafaxine decreases effects of iobenguane I 123 by pharmacodynamic antagonism. Contraindicated. If clinically appropriate, discontinue drugs that decrease uptake of NE for at least 5 half-lives; may cause false-negative imaging results.

• isocarboxazid

  isocarboxazid and venlafaxine both increase serotonin levels. Contraindicated.

• phenelzine

  phenelzine and venlafaxine both increase serotonin levels. Contraindicated.

• posaconazole

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

• procarbazine

  procarbazine and venlafaxine both increase serotonin levels. Contraindicated. Combination is contraindicated within 2 weeks of MAOI use.

• safinamide

  venlafaxine, safinamide. Either increases toxicity of the other by serotonin levels. Contraindicated. Concomitant use could result in life-threatening serotonin syndrome.

• selegiline

  selegiline and venlafaxine both increase serotonin levels. Contraindicated. At least 14 days should elapse between discontinuation of selegiline and initiation of treatment with a serotonergic drug.

• tranylcypromine

  tranylcypromine and venlafaxine both increase serotonin levels. Contraindicated.

Serious - Use Alternative (106)

• abametapir

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

• alfentanil

  venlafaxine and alfentanil both increase serotonin levels. Avoid or Use Alternate Drug. May cause serotonin syndrome

• amiodarone

  amiodarone and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• amisulpride

  amisulpride and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug. ECG monitoring is recommended if coadministered.

• amitriptyline

  venlafaxine and amitriptyline both increase serotonin levels. Avoid or Use Alternate Drug.

• amoxapine

  venlafaxine and amoxapine both increase serotonin levels. Avoid or Use Alternate Drug.

• anagrelide

  anagrelide and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• apalutamide

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

• apixaban

  venlafaxine and apixaban both increase anticoagulation. Avoid or Use Alternate Drug.

• arsenic trioxide

  arsenic trioxide and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• asenapine

  asenapine and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• asenapine transdermal

  asenapine transdermal and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• buprenorphine

  buprenorphine and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• buprenorphine buccal

  buprenorphine buccal and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• buprenorphine subdermal implant

  buprenorphine subdermal implant and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• buprenorphine transdermal

  buprenorphine transdermal and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• buprenorphine, long-acting injection

  buprenorphine, long-acting injection and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• bupropion

  venlafaxine increases toxicity of bupropion by unspecified interaction mechanism. Avoid or Use Alternate Drug. May lower seizure threshold; keep bupropion dose as low as possible.

• buspirone

  venlafaxine and buspirone both increase serotonin levels. Avoid or Use Alternate Drug.

• ceritinib

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

• citalopram

  citalopram and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug. Combination may increase risk of serotonin syndrome or neuroleptic malignant syndrome-like reactions.

• clarithromycin

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

• clomipramine

  venlafaxine and clomipramine both increase serotonin levels. Avoid or Use Alternate Drug.

• cyclobenzaprine

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

• dacomitinib

  dacomitinib will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid use with CYP2D6 substrates where minimal increases in concentration of the CYP2D6 substrate may lead to serious or life-threatening toxicities.

• desflurane

  desflurane and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• desipramine

  venlafaxine and desipramine both increase serotonin levels. Avoid or Use Alternate Drug.

• dextromethorphan

  venlafaxine will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.
  
  venlafaxine and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug.

• disopyramide

  disopyramide and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• dolasetron

  dolasetron, venlafaxine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

• dosulepin

  venlafaxine and dosulepin both increase serotonin levels. Avoid or Use Alternate Drug.

• doxepin

  venlafaxine will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.
  
  venlafaxine and doxepin both increase serotonin levels. Avoid or Use Alternate Drug.

• duloxetine

  duloxetine and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.

• eliglustat

  eliglustat and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• encorafenib

  encorafenib and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• entrectinib

  entrectinib and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• eribulin

  eribulin and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• escitalopram

  escitalopram and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.

• fentanyl

  venlafaxine and fentanyl both increase serotonin levels. Avoid or Use Alternate Drug. May cause serotonin syndrome

• fexinidazole

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

• fluoxetine

  fluoxetine and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.

• fluphenazine

  fluphenazine and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• fluvoxamine

  fluvoxamine and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.

• givosiran

  givosiran will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP2D6 substrates with givosiran. If unavoidable, decrease the CYP2D6 substrate dosage in accordance with approved product labeling.

• granisetron

  granisetron, venlafaxine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

• ibutilide

  ibutilide and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• idelalisib

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

• imipramine

  venlafaxine and imipramine both increase serotonin levels. Avoid or Use Alternate Drug.

• indapamide

  indapamide and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• iobenguane I 131

  venlafaxine will decrease the level or effect of iobenguane I 131 by Other (see comment). Avoid or Use Alternate Drug. Based on the mechanism of action of iobenguane, drugs that reduce catecholamine uptake or that deplete catecholamine stores may interfere with iobenguane uptake into cells, and thus, reduce iobenguane efficacy. Discontinue interfering drugs for at least 5 half-lives before administration of either the dosimetry or an iobenguane dose. Do not administer these drugs until at least 7 days after each iobenguane dose.

• isoflurane

  isoflurane and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• ivosidenib

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

• levomilnacipran

  levomilnacipran and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.

• levorphanol

  venlafaxine and levorphanol both increase serotonin levels. Avoid or Use Alternate Drug. May cause serotonin syndrome

• linezolid

  linezolid and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug. Linezolid may increase serotonin as a result of MAO-A inhibition. If linezolid must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last linezolid dose or after 2 weeks of monitoring, whichever comes first.

• lofepramine

  venlafaxine and lofepramine both increase serotonin levels. Avoid or Use Alternate Drug.

• lonafarnib

  lonafarnib will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with sensitive CYP3A substrates. If coadministration unavoidable, monitor for adverse reactions and reduce CYP3A substrate dose in accordance with product labeling.

• lorcaserin

  venlafaxine and lorcaserin both increase serotonin levels. Avoid or Use Alternate Drug.

• maprotiline

  venlafaxine and maprotiline both increase serotonin levels. Avoid or Use Alternate Drug.

• mefloquine

  mefloquine increases toxicity of venlafaxine by QTc interval. Avoid or Use Alternate Drug. Mefloquine may enhance the QTc prolonging effect of high risk QTc prolonging agents.

• meperidine

  venlafaxine and meperidine both increase serotonin levels. Avoid or Use Alternate Drug.

• methylene blue

  methylene blue and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• metoclopramide

  metoclopramide and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug. Additive effects; increased risk for serotonin syndrome, neuroleptic malignant syndrome, dystonia, or other extrapyramidal reactions

• milnacipran

  milnacipran and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.

• mirtazapine

  mirtazapine and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• nalbuphine

  venlafaxine and nalbuphine both increase serotonin levels. Avoid or Use Alternate Drug. May cause serotonin syndrome

• nefazodone

  nefazodone and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.
  
  nefazodone will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• netupitant/palonosetron

  netupitant/palonosetron, venlafaxine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

• nortriptyline

  venlafaxine will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.
  
  venlafaxine and nortriptyline both increase serotonin levels. Avoid or Use Alternate Drug.

• ondansetron

  ondansetron, venlafaxine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

• opium tincture

  venlafaxine and opium tincture both increase serotonin levels. Avoid or Use Alternate Drug. May cause serotonin syndrome

• oxaliplatin

  oxaliplatin and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• ozanimod

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

• palonosetron

  palonosetron, venlafaxine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

• paroxetine

  paroxetine and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.

• pentamidine

  pentamidine and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• perphenazine

  perphenazine and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• phentermine

  venlafaxine, phentermine. Either increases toxicity of the other by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of serotonin syndrome.

• pimozide

  pimozide and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• procainamide

  procainamide and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• promethazine

  venlafaxine will increase the level or effect of promethazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• protriptyline

  venlafaxine and protriptyline both increase serotonin levels. Avoid or Use Alternate Drug.

• pseudoephedrine

  venlafaxine increases effects of pseudoephedrine by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Avoid or Use Alternate Drug.

• quinidine

  quinidine and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• rasagiline

  rasagiline and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug. Severe CNS toxicity associated with hyperpyrexia has been reported with the combined treatment of an antidepressant and rasagiline. Avoid combination within 14 days of MAOI use.

• remifentanil

  venlafaxine and remifentanil both decrease serotonin levels. Avoid or Use Alternate Drug. May cause serotonin syndrome

• ribociclib

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

• saquinavir

  saquinavir, venlafaxine. Either increases toxicity of the other by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. May increase risk for QT prolongation.

• selegiline transdermal

  selegiline transdermal and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.

• sertraline

  sertraline and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.
  
  sertraline and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• sevoflurane

  sevoflurane and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• siponimod

  siponimod and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• sotalol

  sotalol and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• St John's Wort

  venlafaxine and St John's Wort both increase serotonin levels. Avoid or Use Alternate Drug.

• sufentanil

  venlafaxine and sufentanil both decrease serotonin levels. Avoid or Use Alternate Drug. May cause serotonin syndrome

• tedizolid

  tedizolid, venlafaxine. Either increases effects of the other by Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. both increase serotonin levels; increased risk of serotonin syndrome.

• tetrabenazine

  tetrabenazine and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• thioridazine

  venlafaxine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.
  
  thioridazine and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• toremifene

  venlafaxine and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

• trazodone

  trazodone and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.

• trimipramine

  venlafaxine and trimipramine both increase serotonin levels. Avoid or Use Alternate Drug.

• tucatinib

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

• vilazodone

  venlafaxine, vilazodone. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug. Concomitant therapy should be discontinued immediately if signs or symptoms of serotonin syndrome emerge and supportive symptomatic treatment should be initiated. .

• voriconazole

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

• vortioxetine

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

• voxelotor

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

Monitor Closely (226)

• 5-HTP

  venlafaxine and 5-HTP both increase serotonin levels. Modify Therapy/Monitor Closely.

• abiraterone

  abiraterone increases levels of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Avoid coadministration of abiraterone with substrates of CYP2D6. If alternative therapy cannot be used, exercise caution and consider a dose reduction of the CYP2D6 substrate.

• aceclofenac

  venlafaxine, aceclofenac. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• acemetacin

  venlafaxine, acemetacin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• almotriptan

  almotriptan and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.

• amifampridine

  venlafaxine increases toxicity of amifampridine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Amifampridine can cause seizures. Coadministration with drugs that lower seizure threshold may increase this risk.

• amitriptyline

  amitriptyline and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• amoxapine

  amoxapine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• aripiprazole

  venlafaxine will increase the level or effect of aripiprazole by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  venlafaxine, aripiprazole. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• artemether/lumefantrine

  artemether/lumefantrine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• asenapine

  venlafaxine, asenapine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• aspirin

  venlafaxine, aspirin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• aspirin rectal

  venlafaxine, aspirin rectal. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• aspirin/citric acid/sodium bicarbonate

  venlafaxine, aspirin/citric acid/sodium bicarbonate. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• atomoxetine

  venlafaxine will increase the level or effect of atomoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• benzhydrocodone/acetaminophen

  venlafaxine will increase the level or effect of benzhydrocodone/acetaminophen by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Hydromorphone (<3% of the circulating parent hydrocodone [benzhydrocodone is prodrug of hydrocodone]) is mainly formed by CYP2D6 mediated O-demethylation of hydrocodone. Hydromorphone may contribute to the total analgesic effect of hydrocodone.
  
  benzhydrocodone/acetaminophen, venlafaxine. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Coadministration of drugs that affect the serotonergic neurotransmitter system may result in serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment.

• buprenorphine subdermal implant

  venlafaxine, buprenorphine subdermal implant. Either increases toxicity of the other by serotonin levels. Use Caution/Monitor. Concomitant use could result in life-threatening serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation, and during dose adjustment of the serotonergic drug. Discontinue buprenorphine if serotonin syndrome is suspected.

• buprenorphine, long-acting injection

  venlafaxine, buprenorphine, long-acting injection. Either increases toxicity of the other by serotonin levels. Use Caution/Monitor. Concomitant use could result in life-threatening serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation, and during dose adjustment of the serotonergic drug. Discontinue buprenorphine if serotonin syndrome is suspected.

• bupropion

  bupropion will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• cariprazine

  venlafaxine, cariprazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• carvedilol

  venlafaxine will increase the level or effect of carvedilol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• celecoxib

  venlafaxine, celecoxib. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• chloramphenicol

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

• chlorpromazine

  venlafaxine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  chlorpromazine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• choline magnesium trisalicylate

  venlafaxine, choline magnesium trisalicylate. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• clarithromycin

  clarithromycin and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• clobazam

  clobazam will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Lower doses of drugs metabolized by CYP2D6 may be required when used concomitantly.

• clomipramine

  venlafaxine will increase the level or effect of clomipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  clomipramine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• clopidogrel

  venlafaxine increases effects of clopidogrel by pharmacodynamic synergism. Use Caution/Monitor. SNRIs affect platelet activation; coadministration of SNRIs with clopidogrel may increase the risk of bleeding.

• clozapine

  venlafaxine, clozapine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• cobicistat

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

• cocaine topical

  venlafaxine and cocaine topical both increase serotonin levels. Modify Therapy/Monitor Closely.

• codeine

  venlafaxine will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• crofelemer

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

• cyproheptadine

  cyproheptadine decreases effects of venlafaxine by pharmacodynamic antagonism. Use Caution/Monitor. Cyproheptadine may diminish the serotonergic effect of SNRIs.

• dabrafenib

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

• dasatinib

  dasatinib and venlafaxine both increase QTc interval. Use Caution/Monitor.

• degarelix

  degarelix and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• desipramine

  venlafaxine will increase the level or effect of desipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  desipramine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• deutetrabenazine

  deutetrabenazine and venlafaxine both decrease QTc interval. Use Caution/Monitor. At the maximum recommended dose, deutetrabenazine does not prolong QT interval to a clinically relevant extent. Certain circumstances may increase risk of torsade de pointes and/or sudden death in association with drugs that prolong the QTc interval (eg, bradycardia, hypokalemia or hypomagnesemia, coadministration with other drugs that prolong QTc interval, presence of congenital QT prolongation).

• dexfenfluramine

  venlafaxine and dexfenfluramine both increase serotonin levels. Modify Therapy/Monitor Closely.

• dextroamphetamine

  venlafaxine will increase the level or effect of dextroamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely.
  
  venlafaxine and dextroamphetamine both increase serotonin levels. Modify Therapy/Monitor Closely.

• dextroamphetamine transdermal

  venlafaxine, dextroamphetamine transdermal. Either increases effects of the other by serotonin levels. Modify Therapy/Monitor Closely. Initiate with lower doses and monitor for signs and symptoms of serotonin syndrome, particularly during initiation or dosage increase. If serotonin syndrome occurs, discontinue dextroamphetamine transdermal and concomitant serotonergic drug(s).

• diazepam intranasal

  diazepam intranasal, venlafaxine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may potentiate the CNS-depressant effects of each drug.

• dichlorphenamide

  dichlorphenamide and venlafaxine both decrease serum potassium. Use Caution/Monitor.

• diclofenac

  venlafaxine, diclofenac. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• diflunisal

  venlafaxine, diflunisal. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• dihydroergotamine

  venlafaxine and dihydroergotamine both increase serotonin levels. Modify Therapy/Monitor Closely.

• dihydroergotamine intranasal

  venlafaxine and dihydroergotamine intranasal both increase serotonin levels. Modify Therapy/Monitor Closely.

• dofetilide

  dofetilide and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• dolasetron

  dolasetron and venlafaxine both increase QTc interval. Use Caution/Monitor.

• donepezil

  donepezil and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• doxepin

  doxepin and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• dronedarone

  dronedarone and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• droperidol

  droperidol and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• duloxetine

  venlafaxine will increase the level or effect of duloxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• efavirenz

  efavirenz will decrease the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  efavirenz and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• elagolix

  elagolix decreases levels of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.

• eletriptan

  eletriptan and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.

• eliglustat

  eliglustat increases levels of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the concomitant drug and titrate to clinical effect.

• elvitegravir/cobicistat/emtricitabine/tenofovir DF

  elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.
  
  elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP2D6 inhibitor; caution with CYP2D6 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.

• encorafenib

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

• epinephrine

  epinephrine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• epinephrine racemic

  epinephrine racemic and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• ergotamine

  venlafaxine and ergotamine both increase serotonin levels. Modify Therapy/Monitor Closely.

• erythromycin base

  erythromycin base and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• erythromycin ethylsuccinate

  erythromycin ethylsuccinate and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• erythromycin lactobionate

  erythromycin lactobionate and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• erythromycin stearate

  erythromycin stearate and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• etodolac

  venlafaxine, etodolac. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• fedratinib

  fedratinib will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• fenbufen

  venlafaxine, fenbufen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• fenfluramine

  venlafaxine and fenfluramine both increase serotonin levels. Modify Therapy/Monitor Closely.
  
  fenfluramine, venlafaxine. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Coadministration with drugs that increase serotoninergic effects may increase the risk of serotonin syndrome.

• fenoprofen

  venlafaxine, fenoprofen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• fingolimod

  fingolimod and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• fish oil triglycerides

  fish oil triglycerides will increase the level or effect of venlafaxine by anticoagulation. Use Caution/Monitor. Prolonged bleeding reported in patients taking antiplatelet agents or anticoagulants and oral omega-3 fatty acids. Periodically monitor bleeding time in patients receiving fish oil triglycerides and concomitant antiplatelet agents or anticoagulants.

• flecainide

  venlafaxine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  flecainide and venlafaxine both increase QTc interval. Use Caution/Monitor.

• fluconazole

  fluconazole and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• fluoxetine

  fluoxetine and venlafaxine both increase QTc interval. Use Caution/Monitor.

• fluphenazine

  venlafaxine will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  venlafaxine, fluphenazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• flurbiprofen

  venlafaxine, flurbiprofen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• fluvoxamine

  fluvoxamine and venlafaxine both increase QTc interval. Use Caution/Monitor.

• formoterol

  formoterol and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• foscarnet

  foscarnet and venlafaxine both increase QTc interval. Use Caution/Monitor.

• frovatriptan

  frovatriptan and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.

• gabapentin

  gabapentin, venlafaxine. 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, venlafaxine. 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.

• ganaxolone

  venlafaxine and ganaxolone both increase sedation. Use Caution/Monitor.

• gemifloxacin

  gemifloxacin and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• gilteritinib

  gilteritinib and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• granisetron

  granisetron and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• green tea

  green tea, venlafaxine. Other (see comment). Use Caution/Monitor. Comment: Combination may increase risk of bleeding.

• haloperidol

  venlafaxine will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  haloperidol and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.
  
  venlafaxine, haloperidol. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• hydrocodone

  venlafaxine will increase the level or effect of hydrocodone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Hydromorphone (<3% of the circulating parent hydrocodone) is mainly formed by CYP2D6 mediated O-demethylation of hydrocodone. Hydromorphone may contribute to the total analgesic effect of hydrocodone.
  
  hydrocodone, venlafaxine. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Coadministration of drugs that affect the serotonergic neurotransmitter system may result in serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment.

• hydromorphone

  venlafaxine will increase the level or effect of hydromorphone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• hydroxyzine

  hydroxyzine and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• ibrutinib

  ibrutinib will increase the level or effect of venlafaxine by anticoagulation. Use Caution/Monitor. Ibrutinib may increase the risk of hemorrhage in patients receiving antiplatelet or anticoagulant therapies and monitor for signs of bleeding.

• ibuprofen

  venlafaxine, ibuprofen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• ibuprofen IV

  venlafaxine, ibuprofen IV. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• iloperidone

  venlafaxine will increase the level or effect of iloperidone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  iloperidone and venlafaxine both increase QTc interval. Use Caution/Monitor.
  
  iloperidone increases levels of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.
  
  venlafaxine, iloperidone. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• imipramine

  venlafaxine will increase the level or effect of imipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  imipramine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• indinavir

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

• indomethacin

  venlafaxine, indomethacin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• isoniazid

  venlafaxine and isoniazid both increase serotonin levels. Modify Therapy/Monitor Closely.

• istradefylline

  istradefylline will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.

• itraconazole

  itraconazole and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.
  
  itraconazole will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ketoconazole

  ketoconazole and venlafaxine both increase QTc interval. Use Caution/Monitor.
  
  ketoconazole will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ketoprofen

  venlafaxine, ketoprofen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• ketorolac

  venlafaxine, ketorolac. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• ketorolac intranasal

  venlafaxine, ketorolac intranasal. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• L-tryptophan

  venlafaxine and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.

• lapatinib

  lapatinib and venlafaxine both increase QTc interval. Use Caution/Monitor.

• lasmiditan

  lasmiditan, venlafaxine. 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.
  
  venlafaxine increases effects of lasmiditan by serotonin levels. Use Caution/Monitor. Coadministration may increase risk of serotonin syndrome.

• lemborexant

  lemborexant, venlafaxine. Either increases effects of the other by sedation. Modify Therapy/Monitor Closely. Dosage adjustment may be necessary if lemborexant is coadministered with other CNS depressants because of potentially additive effects.

• lenacapavir

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

• levofloxacin

  levofloxacin and venlafaxine both increase QTc interval. Use Caution/Monitor.

• levoketoconazole

  levoketoconazole will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  levoketoconazole and venlafaxine both increase QTc interval. Use Caution/Monitor.

• lisdexamfetamine

  venlafaxine, lisdexamfetamine. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Initiate with lower doses and monitor for signs and symptoms of serotonin syndrome, particularly during initiation or dosage increase. If serotonin syndrome occurs, discontinue along with concomitant serotonergic drug(s).

• lithium

  venlafaxine and lithium both increase serotonin levels. Modify Therapy/Monitor Closely.
  
  lithium and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• lofepramine

  venlafaxine will increase the level or effect of lofepramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  lofepramine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• lopinavir

  lopinavir increases levels of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity.

• loratadine

  venlafaxine will increase the level or effect of loratadine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• lorcaserin

  lorcaserin will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• lornoxicam

  venlafaxine, lornoxicam. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• loxapine

  venlafaxine, loxapine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• loxapine inhaled

  venlafaxine, loxapine inhaled. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• lsd

  venlafaxine and lsd both increase serotonin levels. Modify Therapy/Monitor Closely.

• lumefantrine

  lumefantrine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• lurasidone

  lurasidone, venlafaxine. 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.
  
  venlafaxine, lurasidone. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• maprotiline

  maprotiline and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• meclofenamate

  venlafaxine, meclofenamate. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• mefenamic acid

  venlafaxine, mefenamic acid. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• meloxicam

  venlafaxine, meloxicam. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• methadone

  methadone and venlafaxine both increase QTc interval. Use Caution/Monitor.

• methamphetamine

  venlafaxine will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• metoprolol

  venlafaxine will increase the level or effect of metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• mexiletine

  venlafaxine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• mifepristone

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

• mirabegron

  mirabegron will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• mirtazapine

  venlafaxine and mirtazapine both increase serotonin levels. Modify Therapy/Monitor Closely.

• mitotane

  mitotane will decrease the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor and adjust venlafaxine dose as necessary

• molindone

  venlafaxine, molindone. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• morphine

  venlafaxine will increase the level or effect of morphine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  venlafaxine and morphine both increase serotonin levels. Modify Therapy/Monitor Closely.

• moxifloxacin

  moxifloxacin and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• nabumetone

  venlafaxine, nabumetone. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• naproxen

  venlafaxine, naproxen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• naratriptan

  naratriptan and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.

• nebivolol

  venlafaxine will increase the level or effect of nebivolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• nilotinib

  nilotinib and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• nirmatrelvir/ritonavir

  nirmatrelvir/ritonavir increases levels of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• nortriptyline

  nortriptyline and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• octreotide

  octreotide and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• octreotide (Antidote)

  octreotide (Antidote) and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• ofloxacin

  ofloxacin and venlafaxine both increase QTc interval. Use Caution/Monitor.

• olanzapine

  venlafaxine, olanzapine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  olanzapine and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• oliceridine

  venlafaxine, oliceridine. Either increases effects of the other by serotonin levels. Modify Therapy/Monitor Closely.

• oxaprozin

  venlafaxine, oxaprozin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• oxycodone

  venlafaxine will increase the level or effect of oxycodone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• oxymorphone

  venlafaxine will increase the level or effect of oxymorphone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• paliperidone

  paliperidone and venlafaxine both increase QTc interval. Use Caution/Monitor.
  
  venlafaxine, paliperidone. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• panobinostat

  panobinostat will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Panobinostat can increase the levels and effects of sensitive CYP2D6 substrates or those with a narrow therapeutic index CYP2D6.

• parecoxib

  venlafaxine, parecoxib. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• paroxetine

  paroxetine and venlafaxine both increase QTc interval. Use Caution/Monitor.

• peginterferon alfa 2b

  peginterferon alfa 2b, venlafaxine. Other (see comment). Use Caution/Monitor. Comment: When patients are administered peginterferon alpha-2b with CYP2D6 substrates, the therapeutic effect of these drugs may be altered. Peginterferon alpha-2b may increase or decrease levels of CYP2D6 substrate.

• pentazocine

  venlafaxine and pentazocine both increase serotonin levels. Modify Therapy/Monitor Closely.

• perphenazine

  venlafaxine will increase the level or effect of perphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  venlafaxine, perphenazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• pimavanserin

  venlafaxine, pimavanserin. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• pimozide

  venlafaxine, pimozide. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• piroxicam

  venlafaxine, piroxicam. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• posaconazole

  posaconazole and venlafaxine both increase QTc interval. Use Caution/Monitor.

• pregabalin

  pregabalin, venlafaxine. 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.

• primaquine

  primaquine and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• prochlorperazine

  venlafaxine will increase the level or effect of prochlorperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  prochlorperazine and venlafaxine both increase QTc interval. Use Caution/Monitor.

• promazine

  promazine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• promethazine

  promethazine and venlafaxine both increase QTc interval. Use Caution/Monitor.

• propafenone

  venlafaxine will increase the level or effect of propafenone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• propranolol

  venlafaxine will increase the level or effect of propranolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• protriptyline

  protriptyline and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• quetiapine

  venlafaxine, quetiapine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• ranolazine

  ranolazine and venlafaxine both increase QTc interval. Use Caution/Monitor.

• remimazolam

  remimazolam, venlafaxine. 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.

• risperidone

  venlafaxine will increase the level or effect of risperidone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  risperidone and venlafaxine both increase QTc interval. Use Caution/Monitor.
  
  venlafaxine, risperidone. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• ritonavir

  ritonavir increases levels of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• rizatriptan

  rizatriptan and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.

• rolapitant

  rolapitant will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Rolapitant may increase plasma concentrations of CYP2D6 substrates for at least 28 days following rolapitant administration.

• romidepsin

  romidepsin and venlafaxine both increase QTc interval. Use Caution/Monitor.

• rucaparib

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

• salicylates (non-asa)

  venlafaxine, salicylates (non-asa). Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• salsalate

  venlafaxine, salsalate. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• SAMe

  venlafaxine and SAMe both increase serotonin levels. Modify Therapy/Monitor Closely.

• sodium sulfate/potassium sulfate/magnesium sulfate/polyethylene glycol

  venlafaxine, sodium sulfate/potassium sulfate/magnesium sulfate/polyethylene glycol. Other (see comment). Use Caution/Monitor. Comment: Caution when bowel preps are used with drugs that cause SIADH or NSAIDs; increased risk for water retention or electrolyte imbalance.

• solifenacin

  solifenacin and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• stiripentol

  stiripentol, venlafaxine. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.

• sufentanil SL

  sufentanil SL, venlafaxine. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Coadministration of drugs that affect the serotonergic neurotransmitter system may result in serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment.

• sulfamethoxazole

  sulfamethoxazole and venlafaxine both increase QTc interval. Use Caution/Monitor.

• sulfasalazine

  venlafaxine, sulfasalazine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• sulindac

  venlafaxine, sulindac. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• sumatriptan

  sumatriptan and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.

• sumatriptan intranasal

  sumatriptan intranasal and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.

• sunitinib

  sunitinib and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• tacrolimus

  tacrolimus and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• tamoxifen

  venlafaxine decreases effects of tamoxifen by decreasing metabolism. Use Caution/Monitor. Inhibition of CYP2D6 metabolism to tamoxifen's active metabolite, endoxifen.

• tapentadol

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

• tazemetostat

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

• tecovirimat

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

• telavancin

  telavancin and venlafaxine both increase QTc interval. Use Caution/Monitor.

• terbinafine

  terbinafine will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Assess need to reduce dose of CYP2D6-metabolized drug.

• thiothixene

  venlafaxine, thiothixene. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• timolol

  venlafaxine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• tipranavir

  tipranavir, venlafaxine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor.
  
  tipranavir will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tolfenamic acid

  venlafaxine, tolfenamic acid. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• tolmetin

  venlafaxine, tolmetin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• tramadol

  venlafaxine and tramadol both increase serotonin levels. Modify Therapy/Monitor Closely.

• trazodone

  trazodone and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• trifluoperazine

  venlafaxine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  trifluoperazine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.
  
  venlafaxine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• trimethoprim

  trimethoprim and venlafaxine both increase QTc interval. Use Caution/Monitor.

• trimipramine

  trimipramine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• tropisetron

  tropisetron and venlafaxine both increase QTc interval. Use Caution/Monitor.

• valbenazine

  valbenazine and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• valerian

  valerian and venlafaxine both increase sedation. Use Caution/Monitor.

• vorapaxar

  venlafaxine, vorapaxar. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive antiplatelet effect may occur; SSRIs and SNRIs may cause platelet serotonin depletion .

• voriconazole

  venlafaxine and voriconazole both increase QTc interval. Use Caution/Monitor.

• vorinostat

  vorinostat and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• warfarin

  venlafaxine, warfarin. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Serotonin release by platelets plays an important role in hemostasis. SSRIs and SNRIs may increase anticoagulation effect of warfarin. .

• ziprasidone

  venlafaxine and ziprasidone both increase QTc interval. Modify Therapy/Monitor Closely.
  
  venlafaxine, ziprasidone. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• zolmitriptan

  zolmitriptan and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.

Minor (37)

• acetazolamide

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

• almotriptan

  venlafaxine, almotriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.

• anastrozole

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

• azithromycin

  azithromycin and venlafaxine both increase QTc interval. Minor/Significance Unknown.

• bumetanide

  bumetanide, venlafaxine. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Possible additive hyponatremia.

• celandine

  celandine decreases effects of venlafaxine by pharmacodynamic antagonism. Minor/Significance Unknown. Based on animal studies.

• codeine

  venlafaxine decreases effects of codeine by decreasing metabolism. Minor/Significance Unknown. Decreased conversion of codeine to active metabolite morphine.

• cyclophosphamide

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

• dexfenfluramine

  venlafaxine will increase the level or effect of dexfenfluramine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• dexmethylphenidate

  dexmethylphenidate increases effects of venlafaxine by decreasing metabolism. Minor/Significance Unknown.

• donepezil

  venlafaxine will increase the level or effect of donepezil by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• eletriptan

  venlafaxine, eletriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.

• encainide

  venlafaxine will increase the level or effect of encainide by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• ethacrynic acid

  ethacrynic acid, venlafaxine. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Possible additive hyponatremia.

• fesoterodine

  venlafaxine will increase the level or effect of fesoterodine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• fluoxetine

  venlafaxine will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• frovatriptan

  venlafaxine, frovatriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.

• furosemide

  furosemide, venlafaxine. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Possible additive hyponatremia.

• galantamine

  venlafaxine will increase the level or effect of galantamine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• larotrectinib

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

• lithium

  venlafaxine, lithium. Mechanism: unknown. Minor/Significance Unknown. Risk of neurotoxicity.

• naratriptan

  venlafaxine, naratriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.

• oxycodone

  venlafaxine decreases effects of oxycodone by decreasing metabolism. Minor/Significance Unknown. Decreased conversion of oxycodone to active metabolite morphine.

• panax ginseng

  panax ginseng increases effects of venlafaxine by pharmacodynamic synergism. Minor/Significance Unknown.

• paroxetine

  venlafaxine will increase the level or effect of paroxetine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• pazopanib

  pazopanib and venlafaxine both increase QTc interval. Minor/Significance Unknown.

• perhexiline

  venlafaxine will increase the level or effect of perhexiline by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• pleurisy root

  pleurisy root decreases effects of venlafaxine by unspecified interaction mechanism. Minor/Significance Unknown. Theoretical interaction.

• promazine

  venlafaxine will increase the level or effect of promazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• rizatriptan

  venlafaxine, rizatriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.

• serdexmethylphenidate/dexmethylphenidate

  serdexmethylphenidate/dexmethylphenidate increases effects of venlafaxine by decreasing metabolism. Minor/Significance Unknown.

• sumatriptan

  venlafaxine, sumatriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.

• sumatriptan intranasal

  venlafaxine, sumatriptan intranasal. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.

• tolterodine

  venlafaxine will increase the level or effect of tolterodine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• torsemide

  torsemide, venlafaxine. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Possible additive hyponatremia.

• tropisetron

  venlafaxine will increase the level or effect of tropisetron by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• zolmitriptan

  venlafaxine, zolmitriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.

• 5-HTP

  Monitor Closely (1)venlafaxine and 5-HTP both increase serotonin levels. Modify Therapy/Monitor Closely.

• abametapir

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

• abiraterone

  Monitor Closely (1)abiraterone increases levels of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Avoid coadministration of abiraterone with substrates of CYP2D6. If alternative therapy cannot be used, exercise caution and consider a dose reduction of the CYP2D6 substrate.

• aceclofenac

  Monitor Closely (1)venlafaxine, aceclofenac. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• acemetacin

  Monitor Closely (1)venlafaxine, acemetacin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• acetazolamide

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

• alfentanil

  Serious - Use Alternative (1)venlafaxine and alfentanil both increase serotonin levels. Avoid or Use Alternate Drug. May cause serotonin syndrome

• almotriptan

  Monitor Closely (1)almotriptan and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.Minor (1)venlafaxine, almotriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.

• amifampridine

  Monitor Closely (1)venlafaxine increases toxicity of amifampridine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Amifampridine can cause seizures. Coadministration with drugs that lower seizure threshold may increase this risk.

• amiodarone

  Serious - Use Alternative (1)amiodarone and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• amisulpride

  Serious - Use Alternative (1)amisulpride and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug. ECG monitoring is recommended if coadministered.

• amitriptyline

  Monitor Closely (1)amitriptyline and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)venlafaxine and amitriptyline both increase serotonin levels. Avoid or Use Alternate Drug.

• amoxapine

  Monitor Closely (1)amoxapine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)venlafaxine and amoxapine both increase serotonin levels. Avoid or Use Alternate Drug.

• anagrelide

  Serious - Use Alternative (1)anagrelide and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• anastrozole

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

• apalutamide

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

• apixaban

  Serious - Use Alternative (1)venlafaxine and apixaban both increase anticoagulation. Avoid or Use Alternate Drug.

• aripiprazole

  Monitor Closely (2)venlafaxine, aripiprazole. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  venlafaxine will increase the level or effect of aripiprazole by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• arsenic trioxide

  Serious - Use Alternative (1)arsenic trioxide and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• artemether/lumefantrine

  Monitor Closely (1)artemether/lumefantrine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• asenapine

  Monitor Closely (1)venlafaxine, asenapine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).Serious - Use Alternative (1)asenapine and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• asenapine transdermal

  Serious - Use Alternative (1)asenapine transdermal and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• aspirin

  Monitor Closely (1)venlafaxine, aspirin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• aspirin rectal

  Monitor Closely (1)venlafaxine, aspirin rectal. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• aspirin/citric acid/sodium bicarbonate

  Monitor Closely (1)venlafaxine, aspirin/citric acid/sodium bicarbonate. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• atomoxetine

  Monitor Closely (1)venlafaxine will increase the level or effect of atomoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• azithromycin

  Minor (1)azithromycin and venlafaxine both increase QTc interval. Minor/Significance Unknown.

• benzhydrocodone/acetaminophen

  Monitor Closely (2)venlafaxine will increase the level or effect of benzhydrocodone/acetaminophen by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Hydromorphone (<3% of the circulating parent hydrocodone [benzhydrocodone is prodrug of hydrocodone]) is mainly formed by CYP2D6 mediated O-demethylation of hydrocodone. Hydromorphone may contribute to the total analgesic effect of hydrocodone.
  
  benzhydrocodone/acetaminophen, venlafaxine. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Coadministration of drugs that affect the serotonergic neurotransmitter system may result in serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment.

• bumetanide

  Minor (1)bumetanide, venlafaxine. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Possible additive hyponatremia.

• buprenorphine

  Serious - Use Alternative (1)buprenorphine and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• buprenorphine buccal

  Serious - Use Alternative (1)buprenorphine buccal and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• buprenorphine subdermal implant

  Monitor Closely (1)venlafaxine, buprenorphine subdermal implant. Either increases toxicity of the other by serotonin levels. Use Caution/Monitor. Concomitant use could result in life-threatening serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation, and during dose adjustment of the serotonergic drug. Discontinue buprenorphine if serotonin syndrome is suspected.Serious - Use Alternative (1)buprenorphine subdermal implant and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• buprenorphine transdermal

  Serious - Use Alternative (1)buprenorphine transdermal and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• buprenorphine, long-acting injection

  Monitor Closely (1)venlafaxine, buprenorphine, long-acting injection. Either increases toxicity of the other by serotonin levels. Use Caution/Monitor. Concomitant use could result in life-threatening serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation, and during dose adjustment of the serotonergic drug. Discontinue buprenorphine if serotonin syndrome is suspected.Serious - Use Alternative (1)buprenorphine, long-acting injection and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• bupropion

  Monitor Closely (1)bupropion will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)venlafaxine increases toxicity of bupropion by unspecified interaction mechanism. Avoid or Use Alternate Drug. May lower seizure threshold; keep bupropion dose as low as possible.

• buspirone

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

• cariprazine

  Monitor Closely (1)venlafaxine, cariprazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• carvedilol

  Monitor Closely (1)venlafaxine will increase the level or effect of carvedilol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• celandine

  Minor (1)celandine decreases effects of venlafaxine by pharmacodynamic antagonism. Minor/Significance Unknown. Based on animal studies.

• celecoxib

  Monitor Closely (1)venlafaxine, celecoxib. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• ceritinib

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

• chloramphenicol

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

• chlorpromazine

  Monitor Closely (2)chlorpromazine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.
  
  venlafaxine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• choline magnesium trisalicylate

  Monitor Closely (1)venlafaxine, choline magnesium trisalicylate. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• citalopram

  Serious - Use Alternative (1)citalopram and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug. Combination may increase risk of serotonin syndrome or neuroleptic malignant syndrome-like reactions.

• clarithromycin

  Monitor Closely (1)clarithromycin and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)clarithromycin will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• clobazam

  Monitor Closely (1)clobazam will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Lower doses of drugs metabolized by CYP2D6 may be required when used concomitantly.

• clomipramine

  Monitor Closely (2)venlafaxine will increase the level or effect of clomipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  clomipramine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)venlafaxine and clomipramine both increase serotonin levels. Avoid or Use Alternate Drug.

• clopidogrel

  Monitor Closely (1)venlafaxine increases effects of clopidogrel by pharmacodynamic synergism. Use Caution/Monitor. SNRIs affect platelet activation; coadministration of SNRIs with clopidogrel may increase the risk of bleeding.

• clozapine

  Monitor Closely (1)venlafaxine, clozapine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• cobicistat

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

• cocaine topical

  Monitor Closely (1)venlafaxine and cocaine topical both increase serotonin levels. Modify Therapy/Monitor Closely.

• codeine

  Monitor Closely (1)venlafaxine will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Minor (1)venlafaxine decreases effects of codeine by decreasing metabolism. Minor/Significance Unknown. Decreased conversion of codeine to active metabolite morphine.

• crofelemer

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

• cyclobenzaprine

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

• cyclophosphamide

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

• cyproheptadine

  Monitor Closely (1)cyproheptadine decreases effects of venlafaxine by pharmacodynamic antagonism. Use Caution/Monitor. Cyproheptadine may diminish the serotonergic effect of SNRIs.

• dabrafenib

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

• dacomitinib

  Serious - Use Alternative (1)dacomitinib will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid use with CYP2D6 substrates where minimal increases in concentration of the CYP2D6 substrate may lead to serious or life-threatening toxicities.

• dasatinib

  Monitor Closely (1)dasatinib and venlafaxine both increase QTc interval. Use Caution/Monitor.

• degarelix

  Monitor Closely (1)degarelix and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• desflurane

  Serious - Use Alternative (1)desflurane and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• desipramine

  Monitor Closely (2)venlafaxine will increase the level or effect of desipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  desipramine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)venlafaxine and desipramine both increase serotonin levels. Avoid or Use Alternate Drug.

• deutetrabenazine

  Monitor Closely (1)deutetrabenazine and venlafaxine both decrease QTc interval. Use Caution/Monitor. At the maximum recommended dose, deutetrabenazine does not prolong QT interval to a clinically relevant extent. Certain circumstances may increase risk of torsade de pointes and/or sudden death in association with drugs that prolong the QTc interval (eg, bradycardia, hypokalemia or hypomagnesemia, coadministration with other drugs that prolong QTc interval, presence of congenital QT prolongation).

• dexfenfluramine

  Monitor Closely (1)venlafaxine and dexfenfluramine both increase serotonin levels. Modify Therapy/Monitor Closely.Minor (1)venlafaxine will increase the level or effect of dexfenfluramine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• dexmethylphenidate

  Minor (1)dexmethylphenidate increases effects of venlafaxine by decreasing metabolism. Minor/Significance Unknown.

• dextroamphetamine

  Monitor Closely (2)venlafaxine will increase the level or effect of dextroamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely.
  
  venlafaxine and dextroamphetamine both increase serotonin levels. Modify Therapy/Monitor Closely.

• dextroamphetamine transdermal

  Monitor Closely (1)venlafaxine, dextroamphetamine transdermal. Either increases effects of the other by serotonin levels. Modify Therapy/Monitor Closely. Initiate with lower doses and monitor for signs and symptoms of serotonin syndrome, particularly during initiation or dosage increase. If serotonin syndrome occurs, discontinue dextroamphetamine transdermal and concomitant serotonergic drug(s).

• dextromethorphan

  Serious - Use Alternative (2)venlafaxine and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug.
  
  venlafaxine will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• diazepam intranasal

  Monitor Closely (1)diazepam intranasal, venlafaxine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may potentiate the CNS-depressant effects of each drug.

• dichlorphenamide

  Monitor Closely (1)dichlorphenamide and venlafaxine both decrease serum potassium. Use Caution/Monitor.

• diclofenac

  Monitor Closely (1)venlafaxine, diclofenac. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• diflunisal

  Monitor Closely (1)venlafaxine, diflunisal. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• dihydroergotamine

  Monitor Closely (1)venlafaxine and dihydroergotamine both increase serotonin levels. Modify Therapy/Monitor Closely.

• dihydroergotamine intranasal

  Monitor Closely (1)venlafaxine and dihydroergotamine intranasal both increase serotonin levels. Modify Therapy/Monitor Closely.

• disopyramide

  Serious - Use Alternative (1)disopyramide and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• dofetilide

  Monitor Closely (1)dofetilide and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• dolasetron

  Monitor Closely (1)dolasetron and venlafaxine both increase QTc interval. Use Caution/Monitor.Serious - Use Alternative (1)dolasetron, venlafaxine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

• donepezil

  Monitor Closely (1)donepezil and venlafaxine both decrease QTc interval. Use Caution/Monitor.Minor (1)venlafaxine will increase the level or effect of donepezil by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• dosulepin

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

• doxepin

  Monitor Closely (1)doxepin and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (2)venlafaxine and doxepin both increase serotonin levels. Avoid or Use Alternate Drug.
  
  venlafaxine will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• dronedarone

  Monitor Closely (1)dronedarone and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• droperidol

  Monitor Closely (1)droperidol and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• duloxetine

  Monitor Closely (1)venlafaxine will increase the level or effect of duloxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)duloxetine and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.

• efavirenz

  Monitor Closely (2)efavirenz will decrease the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  efavirenz and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• elagolix

  Monitor Closely (1)elagolix decreases levels of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.

• eletriptan

  Monitor Closely (1)eletriptan and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.Minor (1)venlafaxine, eletriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.

• eliglustat

  Monitor Closely (1)eliglustat increases levels of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the concomitant drug and titrate to clinical effect.Serious - Use Alternative (1)eliglustat and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• elvitegravir/cobicistat/emtricitabine/tenofovir DF

  Monitor Closely (2)elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.
  
  elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP2D6 inhibitor; caution with CYP2D6 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.

• encainide

  Minor (1)venlafaxine will increase the level or effect of encainide by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• encorafenib

  Monitor Closely (1)encorafenib, venlafaxine. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.Serious - Use Alternative (1)encorafenib and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• entrectinib

  Serious - Use Alternative (1)entrectinib and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• epinephrine

  Monitor Closely (1)epinephrine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• epinephrine racemic

  Monitor Closely (1)epinephrine racemic and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• ergotamine

  Monitor Closely (1)venlafaxine and ergotamine both increase serotonin levels. Modify Therapy/Monitor Closely.

• eribulin

  Serious - Use Alternative (1)eribulin and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• erythromycin base

  Monitor Closely (1)erythromycin base and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• erythromycin ethylsuccinate

  Monitor Closely (1)erythromycin ethylsuccinate and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• erythromycin lactobionate

  Monitor Closely (1)erythromycin lactobionate and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• erythromycin stearate

  Monitor Closely (1)erythromycin stearate and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• escitalopram

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

• ethacrynic acid

  Minor (1)ethacrynic acid, venlafaxine. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Possible additive hyponatremia.

• etodolac

  Monitor Closely (1)venlafaxine, etodolac. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• fedratinib

  Monitor Closely (2)fedratinib will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• fenbufen

  Monitor Closely (1)venlafaxine, fenbufen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• fenfluramine

  Monitor Closely (2)fenfluramine, venlafaxine. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Coadministration with drugs that increase serotoninergic effects may increase the risk of serotonin syndrome.
  
  venlafaxine and fenfluramine both increase serotonin levels. Modify Therapy/Monitor Closely.

• fenoprofen

  Monitor Closely (1)venlafaxine, fenoprofen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• fentanyl

  Serious - Use Alternative (1)venlafaxine and fentanyl both increase serotonin levels. Avoid or Use Alternate Drug. May cause serotonin syndrome

• fesoterodine

  Minor (1)venlafaxine will increase the level or effect of fesoterodine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• fexinidazole

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

• fingolimod

  Monitor Closely (1)fingolimod and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• fish oil triglycerides

  Monitor Closely (1)fish oil triglycerides will increase the level or effect of venlafaxine by anticoagulation. Use Caution/Monitor. Prolonged bleeding reported in patients taking antiplatelet agents or anticoagulants and oral omega-3 fatty acids. Periodically monitor bleeding time in patients receiving fish oil triglycerides and concomitant antiplatelet agents or anticoagulants.

• flecainide

  Monitor Closely (2)venlafaxine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  flecainide and venlafaxine both increase QTc interval. Use Caution/Monitor.

• fluconazole

  Monitor Closely (1)fluconazole and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• fluoxetine

  Monitor Closely (1)fluoxetine and venlafaxine both increase QTc interval. Use Caution/Monitor.Serious - Use Alternative (1)fluoxetine and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.Minor (1)venlafaxine will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• fluphenazine

  Monitor Closely (2)venlafaxine, fluphenazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  venlafaxine will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)fluphenazine and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• flurbiprofen

  Monitor Closely (1)venlafaxine, flurbiprofen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• fluvoxamine

  Monitor Closely (1)fluvoxamine and venlafaxine both increase QTc interval. Use Caution/Monitor.Serious - Use Alternative (1)fluvoxamine and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.

• formoterol

  Monitor Closely (1)formoterol and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• foscarnet

  Monitor Closely (1)foscarnet and venlafaxine both increase QTc interval. Use Caution/Monitor.

• frovatriptan

  Monitor Closely (1)frovatriptan and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.Minor (1)venlafaxine, frovatriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.

• furosemide

  Minor (1)furosemide, venlafaxine. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Possible additive hyponatremia.

• gabapentin

  Monitor Closely (1)gabapentin, venlafaxine. 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, venlafaxine. 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)venlafaxine will increase the level or effect of galantamine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• ganaxolone

  Monitor Closely (1)venlafaxine and ganaxolone both increase sedation. Use Caution/Monitor.

• gemifloxacin

  Monitor Closely (1)gemifloxacin and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• gilteritinib

  Monitor Closely (1)gilteritinib and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• givosiran

  Serious - Use Alternative (1)givosiran will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP2D6 substrates with givosiran. If unavoidable, decrease the CYP2D6 substrate dosage in accordance with approved product labeling.

• granisetron

  Monitor Closely (1)granisetron and venlafaxine both decrease QTc interval. Use Caution/Monitor.Serious - Use Alternative (1)granisetron, venlafaxine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

• green tea

  Monitor Closely (1)green tea, venlafaxine. Other (see comment). Use Caution/Monitor. Comment: Combination may increase risk of bleeding.

• haloperidol

  Monitor Closely (3)venlafaxine will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  venlafaxine, haloperidol. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  haloperidol and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• hydrocodone

  Monitor Closely (2)hydrocodone, venlafaxine. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Coadministration of drugs that affect the serotonergic neurotransmitter system may result in serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment.
  
  venlafaxine will increase the level or effect of hydrocodone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Hydromorphone (<3% of the circulating parent hydrocodone) is mainly formed by CYP2D6 mediated O-demethylation of hydrocodone. Hydromorphone may contribute to the total analgesic effect of hydrocodone.

• hydromorphone

  Monitor Closely (1)venlafaxine will increase the level or effect of hydromorphone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• hydroxyzine

  Monitor Closely (1)hydroxyzine and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• ibrutinib

  Monitor Closely (1)ibrutinib will increase the level or effect of venlafaxine by anticoagulation. Use Caution/Monitor. Ibrutinib may increase the risk of hemorrhage in patients receiving antiplatelet or anticoagulant therapies and monitor for signs of bleeding.

• ibuprofen

  Monitor Closely (1)venlafaxine, ibuprofen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• ibuprofen IV

  Monitor Closely (1)venlafaxine, ibuprofen IV. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• ibutilide

  Serious - Use Alternative (1)ibutilide and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• idelalisib

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

• iloperidone

  Monitor Closely (4)venlafaxine, iloperidone. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  iloperidone increases levels of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.
  
  venlafaxine will increase the level or effect of iloperidone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  iloperidone and venlafaxine both increase QTc interval. Use Caution/Monitor.

• imipramine

  Monitor Closely (2)venlafaxine will increase the level or effect of imipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  imipramine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)venlafaxine and imipramine both increase serotonin levels. Avoid or Use Alternate Drug.

• indapamide

  Serious - Use Alternative (1)indapamide and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• indinavir

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

• indomethacin

  Monitor Closely (1)venlafaxine, indomethacin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• iobenguane I 123

  Contraindicated (1)venlafaxine decreases effects of iobenguane I 123 by pharmacodynamic antagonism. Contraindicated. If clinically appropriate, discontinue drugs that decrease uptake of NE for at least 5 half-lives; may cause false-negative imaging results.

• iobenguane I 131

  Serious - Use Alternative (1)venlafaxine will decrease the level or effect of iobenguane I 131 by Other (see comment). Avoid or Use Alternate Drug. Based on the mechanism of action of iobenguane, drugs that reduce catecholamine uptake or that deplete catecholamine stores may interfere with iobenguane uptake into cells, and thus, reduce iobenguane efficacy. Discontinue interfering drugs for at least 5 half-lives before administration of either the dosimetry or an iobenguane dose. Do not administer these drugs until at least 7 days after each iobenguane dose.

• isocarboxazid

  Contraindicated (1)isocarboxazid and venlafaxine both increase serotonin levels. Contraindicated.

• isoflurane

  Serious - Use Alternative (1)isoflurane and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• isoniazid

  Monitor Closely (1)venlafaxine and isoniazid both increase serotonin levels. Modify Therapy/Monitor Closely.

• istradefylline

  Monitor Closely (1)istradefylline will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.

• itraconazole

  Monitor Closely (2)itraconazole will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  itraconazole and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• ivosidenib

  Serious - Use Alternative (1)ivosidenib will decrease the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternative therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.

• ketoconazole

  Monitor Closely (2)ketoconazole and venlafaxine both increase QTc interval. Use Caution/Monitor.
  
  ketoconazole will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ketoprofen

  Monitor Closely (1)venlafaxine, ketoprofen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• ketorolac

  Monitor Closely (1)venlafaxine, ketorolac. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• ketorolac intranasal

  Monitor Closely (1)venlafaxine, ketorolac intranasal. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• L-tryptophan

  Monitor Closely (1)venlafaxine and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.

• lapatinib

  Monitor Closely (1)lapatinib and venlafaxine both increase QTc interval. Use Caution/Monitor.

• larotrectinib

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

• lasmiditan

  Monitor Closely (2)lasmiditan, venlafaxine. 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.
  
  venlafaxine increases effects of lasmiditan by serotonin levels. Use Caution/Monitor. Coadministration may increase risk of serotonin syndrome.

• lemborexant

  Monitor Closely (1)lemborexant, venlafaxine. Either increases effects of the other by sedation. Modify Therapy/Monitor Closely. Dosage adjustment may be necessary if lemborexant is coadministered with other CNS depressants because of potentially additive effects.

• lenacapavir

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

• levofloxacin

  Monitor Closely (1)levofloxacin and venlafaxine both increase QTc interval. Use Caution/Monitor.

• levoketoconazole

  Monitor Closely (2)levoketoconazole will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  levoketoconazole and venlafaxine both increase QTc interval. Use Caution/Monitor.

• levomilnacipran

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

• levorphanol

  Serious - Use Alternative (1)venlafaxine and levorphanol both increase serotonin levels. Avoid or Use Alternate Drug. May cause serotonin syndrome

• linezolid

  Serious - Use Alternative (1)linezolid and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug. Linezolid may increase serotonin as a result of MAO-A inhibition. If linezolid must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last linezolid dose or after 2 weeks of monitoring, whichever comes first.

• lisdexamfetamine

  Monitor Closely (1)venlafaxine, lisdexamfetamine. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Initiate with lower doses and monitor for signs and symptoms of serotonin syndrome, particularly during initiation or dosage increase. If serotonin syndrome occurs, discontinue along with concomitant serotonergic drug(s).

• lithium

  Monitor Closely (2)venlafaxine and lithium both increase serotonin levels. Modify Therapy/Monitor Closely.
  
  lithium and venlafaxine both decrease QTc interval. Use Caution/Monitor.Minor (1)venlafaxine, lithium. Mechanism: unknown. Minor/Significance Unknown. Risk of neurotoxicity.

• lofepramine

  Monitor Closely (2)venlafaxine will increase the level or effect of lofepramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  lofepramine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)venlafaxine and lofepramine both increase serotonin levels. Avoid or Use Alternate Drug.

• lonafarnib

  Serious - Use Alternative (1)lonafarnib will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with sensitive CYP3A substrates. If coadministration unavoidable, monitor for adverse reactions and reduce CYP3A substrate dose in accordance with product labeling.

• lopinavir

  Monitor Closely (1)lopinavir increases levels of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity.

• loratadine

  Monitor Closely (1)venlafaxine will increase the level or effect of loratadine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• lorcaserin

  Monitor Closely (1)lorcaserin will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)venlafaxine and lorcaserin both increase serotonin levels. Avoid or Use Alternate Drug.

• lornoxicam

  Monitor Closely (1)venlafaxine, lornoxicam. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• loxapine

  Monitor Closely (1)venlafaxine, loxapine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• loxapine inhaled

  Monitor Closely (1)venlafaxine, loxapine inhaled. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• lsd

  Monitor Closely (1)venlafaxine and lsd both increase serotonin levels. Modify Therapy/Monitor Closely.

• lumefantrine

  Monitor Closely (1)lumefantrine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• lurasidone

  Monitor Closely (2)lurasidone, venlafaxine. 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.
  
  venlafaxine, lurasidone. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• maprotiline

  Monitor Closely (1)maprotiline and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)venlafaxine and maprotiline both increase serotonin levels. Avoid or Use Alternate Drug.

• meclofenamate

  Monitor Closely (1)venlafaxine, meclofenamate. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• mefenamic acid

  Monitor Closely (1)venlafaxine, mefenamic acid. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• mefloquine

  Serious - Use Alternative (1)mefloquine increases toxicity of venlafaxine by QTc interval. Avoid or Use Alternate Drug. Mefloquine may enhance the QTc prolonging effect of high risk QTc prolonging agents.

• meloxicam

  Monitor Closely (1)venlafaxine, meloxicam. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• meperidine

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

• methadone

  Monitor Closely (1)methadone and venlafaxine both increase QTc interval. Use Caution/Monitor.

• methamphetamine

  Monitor Closely (1)venlafaxine will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• methylene blue

  Serious - Use Alternative (1)methylene blue and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• metoclopramide

  Serious - Use Alternative (1)metoclopramide and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug. Additive effects; increased risk for serotonin syndrome, neuroleptic malignant syndrome, dystonia, or other extrapyramidal reactions

• metoprolol

  Monitor Closely (1)venlafaxine will increase the level or effect of metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• mexiletine

  Monitor Closely (1)venlafaxine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• mifepristone

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

• milnacipran

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

• mirabegron

  Monitor Closely (1)mirabegron will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• mirtazapine

  Monitor Closely (1)venlafaxine and mirtazapine both increase serotonin levels. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)mirtazapine and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• mitotane

  Monitor Closely (1)mitotane will decrease the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor and adjust venlafaxine dose as necessary

• molindone

  Monitor Closely (1)venlafaxine, molindone. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• morphine

  Monitor Closely (2)venlafaxine and morphine both increase serotonin levels. Modify Therapy/Monitor Closely.
  
  venlafaxine will increase the level or effect of morphine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• moxifloxacin

  Monitor Closely (1)moxifloxacin and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• nabumetone

  Monitor Closely (1)venlafaxine, nabumetone. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• nalbuphine

  Serious - Use Alternative (1)venlafaxine and nalbuphine both increase serotonin levels. Avoid or Use Alternate Drug. May cause serotonin syndrome

• naproxen

  Monitor Closely (1)venlafaxine, naproxen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• naratriptan

  Monitor Closely (1)naratriptan and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.Minor (1)venlafaxine, naratriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.

• nebivolol

  Monitor Closely (1)venlafaxine will increase the level or effect of nebivolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• nefazodone

  Serious - Use Alternative (2)nefazodone and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.
  
  nefazodone will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• netupitant/palonosetron

  Serious - Use Alternative (1)netupitant/palonosetron, venlafaxine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

• nilotinib

  Monitor Closely (1)nilotinib and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• nirmatrelvir/ritonavir

  Monitor Closely (1)nirmatrelvir/ritonavir increases levels of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• nortriptyline

  Monitor Closely (1)nortriptyline and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (2)venlafaxine and nortriptyline both increase serotonin levels. Avoid or Use Alternate Drug.
  
  venlafaxine will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• octreotide

  Monitor Closely (1)octreotide and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• octreotide (Antidote)

  Monitor Closely (1)octreotide (Antidote) and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• ofloxacin

  Monitor Closely (1)ofloxacin and venlafaxine both increase QTc interval. Use Caution/Monitor.

• olanzapine

  Monitor Closely (2)venlafaxine, olanzapine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  olanzapine and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• oliceridine

  Monitor Closely (1)venlafaxine, oliceridine. Either increases effects of the other by serotonin levels. Modify Therapy/Monitor Closely.

• ondansetron

  Serious - Use Alternative (1)ondansetron, venlafaxine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

• opium tincture

  Serious - Use Alternative (1)venlafaxine and opium tincture both increase serotonin levels. Avoid or Use Alternate Drug. May cause serotonin syndrome

• oxaliplatin

  Serious - Use Alternative (1)oxaliplatin and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• oxaprozin

  Monitor Closely (1)venlafaxine, oxaprozin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• oxycodone

  Monitor Closely (1)venlafaxine will increase the level or effect of oxycodone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Minor (1)venlafaxine decreases effects of oxycodone by decreasing metabolism. Minor/Significance Unknown. Decreased conversion of oxycodone to active metabolite morphine.

• oxymorphone

  Monitor Closely (1)venlafaxine will increase the level or effect of oxymorphone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• ozanimod

  Serious - Use Alternative (1)ozanimod increases toxicity of venlafaxine by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Avoid or Use Alternate Drug. Because the active metabolite of ozanimod inhibits MAO-B in vitro, there is a potential for serious adverse reactions, including hypertensive crisis. Therefore, coadministration of ozanimod with drugs that can increase norepinephrine or serotonin is not recommended. Monitor for hypertension with concomitant use.

• paliperidone

  Monitor Closely (2)venlafaxine, paliperidone. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  paliperidone and venlafaxine both increase QTc interval. Use Caution/Monitor.

• palonosetron

  Serious - Use Alternative (1)palonosetron, venlafaxine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.

• panax ginseng

  Minor (1)panax ginseng increases effects of venlafaxine by pharmacodynamic synergism. Minor/Significance Unknown.

• panobinostat

  Monitor Closely (1)panobinostat will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Panobinostat can increase the levels and effects of sensitive CYP2D6 substrates or those with a narrow therapeutic index CYP2D6.

• parecoxib

  Monitor Closely (1)venlafaxine, parecoxib. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• paroxetine

  Monitor Closely (1)paroxetine and venlafaxine both increase QTc interval. Use Caution/Monitor.Serious - Use Alternative (1)paroxetine and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.Minor (1)venlafaxine will increase the level or effect of paroxetine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• pazopanib

  Minor (1)pazopanib and venlafaxine both increase QTc interval. Minor/Significance Unknown.

• peginterferon alfa 2b

  Monitor Closely (1)peginterferon alfa 2b, venlafaxine. Other (see comment). Use Caution/Monitor. Comment: When patients are administered peginterferon alpha-2b with CYP2D6 substrates, the therapeutic effect of these drugs may be altered. Peginterferon alpha-2b may increase or decrease levels of CYP2D6 substrate.

• pentamidine

  Serious - Use Alternative (1)pentamidine and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• pentazocine

  Monitor Closely (1)venlafaxine and pentazocine both increase serotonin levels. Modify Therapy/Monitor Closely.

• perhexiline

  Minor (1)venlafaxine will increase the level or effect of perhexiline by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• perphenazine

  Monitor Closely (2)venlafaxine, perphenazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  venlafaxine will increase the level or effect of perphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)perphenazine and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• phenelzine

  Contraindicated (1)phenelzine and venlafaxine both increase serotonin levels. Contraindicated.

• phentermine

  Serious - Use Alternative (1)venlafaxine, phentermine. Either increases toxicity of the other by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of serotonin syndrome.

• pimavanserin

  Monitor Closely (1)venlafaxine, pimavanserin. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• pimozide

  Monitor Closely (1)venlafaxine, pimozide. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).Serious - Use Alternative (1)pimozide and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• piroxicam

  Monitor Closely (1)venlafaxine, piroxicam. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• pleurisy root

  Minor (1)pleurisy root decreases effects of venlafaxine by unspecified interaction mechanism. Minor/Significance Unknown. Theoretical interaction.

• posaconazole

  Contraindicated (1)posaconazole will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.Monitor Closely (1)posaconazole and venlafaxine both increase QTc interval. Use Caution/Monitor.

• pregabalin

  Monitor Closely (1)pregabalin, venlafaxine. 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.

• primaquine

  Monitor Closely (1)primaquine and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• procainamide

  Serious - Use Alternative (1)procainamide and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• procarbazine

  Contraindicated (1)procarbazine and venlafaxine both increase serotonin levels. Contraindicated. Combination is contraindicated within 2 weeks of MAOI use.

• prochlorperazine

  Monitor Closely (2)prochlorperazine and venlafaxine both increase QTc interval. Use Caution/Monitor.
  
  venlafaxine will increase the level or effect of prochlorperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• promazine

  Monitor Closely (1)promazine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.Minor (1)venlafaxine will increase the level or effect of promazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• promethazine

  Monitor Closely (1)promethazine and venlafaxine both increase QTc interval. Use Caution/Monitor.Serious - Use Alternative (1)venlafaxine will increase the level or effect of promethazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• propafenone

  Monitor Closely (1)venlafaxine will increase the level or effect of propafenone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• propranolol

  Monitor Closely (1)venlafaxine will increase the level or effect of propranolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• protriptyline

  Monitor Closely (1)protriptyline and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)venlafaxine and protriptyline both increase serotonin levels. Avoid or Use Alternate Drug.

• pseudoephedrine

  Serious - Use Alternative (1)venlafaxine increases effects of pseudoephedrine by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Avoid or Use Alternate Drug.

• quetiapine

  Monitor Closely (1)venlafaxine, quetiapine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• quinidine

  Serious - Use Alternative (1)quinidine and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• ranolazine

  Monitor Closely (1)ranolazine and venlafaxine both increase QTc interval. Use Caution/Monitor.

• rasagiline

  Serious - Use Alternative (1)rasagiline and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug. Severe CNS toxicity associated with hyperpyrexia has been reported with the combined treatment of an antidepressant and rasagiline. Avoid combination within 14 days of MAOI use.

• remifentanil

  Serious - Use Alternative (1)venlafaxine and remifentanil both decrease serotonin levels. Avoid or Use Alternate Drug. May cause serotonin syndrome

• remimazolam

  Monitor Closely (1)remimazolam, venlafaxine. 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.

• ribociclib

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

• risperidone

  Monitor Closely (3)venlafaxine, risperidone. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  venlafaxine will increase the level or effect of risperidone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  risperidone and venlafaxine both increase QTc interval. Use Caution/Monitor.

• ritonavir

  Monitor Closely (1)ritonavir increases levels of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• rizatriptan

  Monitor Closely (1)rizatriptan and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.Minor (1)venlafaxine, rizatriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.

• rolapitant

  Monitor Closely (1)rolapitant will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Rolapitant may increase plasma concentrations of CYP2D6 substrates for at least 28 days following rolapitant administration.

• romidepsin

  Monitor Closely (1)romidepsin and venlafaxine both increase QTc interval. Use Caution/Monitor.

• rucaparib

  Monitor Closely (1)rucaparib will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.

• safinamide

  Contraindicated (1)venlafaxine, safinamide. Either increases toxicity of the other by serotonin levels. Contraindicated. Concomitant use could result in life-threatening serotonin syndrome.

• salicylates (non-asa)

  Monitor Closely (1)venlafaxine, salicylates (non-asa). Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• salsalate

  Monitor Closely (1)venlafaxine, salsalate. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• SAMe

  Monitor Closely (1)venlafaxine and SAMe both increase serotonin levels. Modify Therapy/Monitor Closely.

• saquinavir

  Serious - Use Alternative (1)saquinavir, venlafaxine. Either increases toxicity of the other by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. May increase risk for QT prolongation.

• selegiline

  Contraindicated (1)selegiline and venlafaxine both increase serotonin levels. Contraindicated. At least 14 days should elapse between discontinuation of selegiline and initiation of treatment with a serotonergic drug.

• selegiline transdermal

  Serious - Use Alternative (1)selegiline transdermal and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.

• serdexmethylphenidate/dexmethylphenidate

  Minor (1)serdexmethylphenidate/dexmethylphenidate increases effects of venlafaxine by decreasing metabolism. Minor/Significance Unknown.

• sertraline

  Serious - Use Alternative (2)sertraline and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.
  
  sertraline and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• sevoflurane

  Serious - Use Alternative (1)sevoflurane and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• siponimod

  Serious - Use Alternative (1)siponimod and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• sodium sulfate/potassium sulfate/magnesium sulfate/polyethylene glycol

  Monitor Closely (1)venlafaxine, sodium sulfate/potassium sulfate/magnesium sulfate/polyethylene glycol. Other (see comment). Use Caution/Monitor. Comment: Caution when bowel preps are used with drugs that cause SIADH or NSAIDs; increased risk for water retention or electrolyte imbalance.

• solifenacin

  Monitor Closely (1)solifenacin and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• sotalol

  Serious - Use Alternative (1)sotalol and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.

• St John's Wort

  Serious - Use Alternative (1)venlafaxine and St John's Wort both increase serotonin levels. Avoid or Use Alternate Drug.

• stiripentol

  Monitor Closely (1)stiripentol, venlafaxine. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.

• sufentanil

  Serious - Use Alternative (1)venlafaxine and sufentanil both decrease serotonin levels. Avoid or Use Alternate Drug. May cause serotonin syndrome

• sufentanil SL

  Monitor Closely (1)sufentanil SL, venlafaxine. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Coadministration of drugs that affect the serotonergic neurotransmitter system may result in serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment.

• sulfamethoxazole

  Monitor Closely (1)sulfamethoxazole and venlafaxine both increase QTc interval. Use Caution/Monitor.

• sulfasalazine

  Monitor Closely (1)venlafaxine, sulfasalazine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• sulindac

  Monitor Closely (1)venlafaxine, sulindac. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• sumatriptan

  Monitor Closely (1)sumatriptan and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.Minor (1)venlafaxine, sumatriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.

• sumatriptan intranasal

  Monitor Closely (1)sumatriptan intranasal and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.Minor (1)venlafaxine, sumatriptan intranasal. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.

• sunitinib

  Monitor Closely (1)sunitinib and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• tacrolimus

  Monitor Closely (1)tacrolimus and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• tamoxifen

  Monitor Closely (1)venlafaxine decreases effects of tamoxifen by decreasing metabolism. Use Caution/Monitor. Inhibition of CYP2D6 metabolism to tamoxifen's active metabolite, endoxifen.

• tapentadol

  Monitor Closely (1)venlafaxine and tapentadol both increase serotonin levels. Modify Therapy/Monitor Closely.

• tazemetostat

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

• tecovirimat

  Monitor Closely (1)tecovirimat will decrease the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.

• tedizolid

  Serious - Use Alternative (1)tedizolid, venlafaxine. Either increases effects of the other by Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. both increase serotonin levels; increased risk of serotonin syndrome.

• telavancin

  Monitor Closely (1)telavancin and venlafaxine both increase QTc interval. Use Caution/Monitor.

• terbinafine

  Monitor Closely (1)terbinafine will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Assess need to reduce dose of CYP2D6-metabolized drug.

• tetrabenazine

  Serious - Use Alternative (1)tetrabenazine and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• thioridazine

  Serious - Use Alternative (2)thioridazine and venlafaxine both increase QTc interval. Avoid or Use Alternate Drug.
  
  venlafaxine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• thiothixene

  Monitor Closely (1)venlafaxine, thiothixene. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• timolol

  Monitor Closely (1)venlafaxine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• tipranavir

  Monitor Closely (2)tipranavir, venlafaxine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor.
  
  tipranavir will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tolfenamic acid

  Monitor Closely (1)venlafaxine, tolfenamic acid. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• tolmetin

  Monitor Closely (1)venlafaxine, tolmetin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.

• tolterodine

  Minor (1)venlafaxine will increase the level or effect of tolterodine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• toremifene

  Serious - Use Alternative (1)venlafaxine and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

• torsemide

  Minor (1)torsemide, venlafaxine. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Possible additive hyponatremia.

• tramadol

  Monitor Closely (1)venlafaxine and tramadol both increase serotonin levels. Modify Therapy/Monitor Closely.

• tranylcypromine

  Contraindicated (1)tranylcypromine and venlafaxine both increase serotonin levels. Contraindicated.

• trazodone

  Monitor Closely (1)trazodone and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)trazodone and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.

• trifluoperazine

  Monitor Closely (3)venlafaxine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  trifluoperazine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.
  
  venlafaxine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• trimethoprim

  Monitor Closely (1)trimethoprim and venlafaxine both increase QTc interval. Use Caution/Monitor.

• trimipramine

  Monitor Closely (1)trimipramine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)venlafaxine and trimipramine both increase serotonin levels. Avoid or Use Alternate Drug.

• tropisetron

  Monitor Closely (1)tropisetron and venlafaxine both increase QTc interval. Use Caution/Monitor.Minor (1)venlafaxine will increase the level or effect of tropisetron by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• tucatinib

  Serious - Use Alternative (1)tucatinib will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.

• valbenazine

  Monitor Closely (1)valbenazine and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• valerian

  Monitor Closely (1)valerian and venlafaxine both increase sedation. Use Caution/Monitor.

• vilazodone

  Serious - Use Alternative (1)venlafaxine, vilazodone. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug. Concomitant therapy should be discontinued immediately if signs or symptoms of serotonin syndrome emerge and supportive symptomatic treatment should be initiated. .

• vorapaxar

  Monitor Closely (1)venlafaxine, vorapaxar. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive antiplatelet effect may occur; SSRIs and SNRIs may cause platelet serotonin depletion .

• voriconazole

  Monitor Closely (1)venlafaxine and voriconazole both increase QTc interval. Use Caution/Monitor.Serious - Use Alternative (1)voriconazole will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• vorinostat

  Monitor Closely (1)vorinostat and venlafaxine both decrease QTc interval. Use Caution/Monitor.

• vortioxetine

  Serious - Use Alternative (1)venlafaxine, vortioxetine. Either increases effects of the other by serotonin levels. Avoid or Use Alternate Drug.

• voxelotor

  Serious - Use Alternative (1)voxelotor will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.

• warfarin

  Monitor Closely (1)venlafaxine, warfarin. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Serotonin release by platelets plays an important role in hemostasis. SSRIs and SNRIs may increase anticoagulation effect of warfarin. .

• ziprasidone

  Monitor Closely (2)venlafaxine, ziprasidone. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  venlafaxine and ziprasidone both increase QTc interval. Modify Therapy/Monitor Closely.

• zolmitriptan

  Monitor Closely (1)zolmitriptan and venlafaxine both increase serotonin levels. Modify Therapy/Monitor Closely.Minor (1)venlafaxine, zolmitriptan. Mechanism: unknown. Minor/Significance Unknown. Risk of weakness, dyspnea, chest pain.