olanzapine (Rx)

Schizophrenia

PO

• 5-10 mg/day initially; if necessary, may be titrated upward in increments of 5 mg/day at intervals >1 week
• Maintenance: 10-20 mg/day; not to exceed 20 mg/day

Recommended IM, extended-release dose based on oral dosage

• Oral dosage 10 mg/day: 210 mg IM every 2 weeks or 405 mg IM every 4 weeks for 1st 8 weeks, then 150 mg every 2 weeks or 300 mg every 4 weeks
• Oral dosage 15 mg/day: 300 mg IM every 2 weeks for 1st 8 weeks, then 210 mg every 2 weeks or 405 mg every 4 weeks
• Oral dosage 20 mg/day: 300 mg IM every 2 weeks for 1st 8 weeks, then 300 mg every 2 weeks

Bipolar Mania

Indicated for acute/maintenance treatment of manic or mixed episodes associated with bipolar 1 disorder; may be used adjunctively to valproate or lithium in the treatment of manic or mixed episodes associated with bipolar disorder

Monotherapy: 10-15 mg/day PO initially; may be titrated upward in increments of 5 mg/day at intervals >24 hr

Adjunct to lithium or valproate: 10 mg/day PO initially

Maintenance: 5-20 mg/day PO; not to exceed 20 mg/day

Agitation Associated with Schizophrenia and Bipolar I Mania

IM, short-acting: 2.5-10 mg/dose; additional doses (up to 10 mg) may be considered; administer subsequent doses 2 hr after initial dose and 4 hr after 2nd dose if necessary; not to exceed 30 mg/day

See Dosing Considerations

Bipolar Depression

Indicated for depressive episodes associated with bipolar I disorder in combination with fluoxetine

5 mg PO in evening; adjusted to range of 5-12.5 mg/day

Safety of coadministered doses greater than olanzapine 18 mg with fluoxetine 75 mg have not been evaluated

Chemotherapy Associated Nausea or Vomiting (Off-label)

Off-label use for prevention of chemotherapy associated nausea or vomiting in combination with 5-HT3 antagonist and dexamethasone (N Engl J Med 2016;375[2]:134-42)

Breakthrough nausea and vomiting: 5-10 mg PO qDay for 3 days, when not used for acute and delayed emesis prevention

Acute and delayed emesis prevention

• Off-label use for prevention of chemotherapy associated nausea or vomiting in combination with 5-HT3 antagonist and dexamethasone
• In combination with dexamethasone and a 5-HT3 antagonist (eg, palonosetron, aprepitant)
• High emetic risk IV chemotherapy: 10 mg PO the day of chemotherapy (day 1), followed by 10 mg PO qDay (days 2-4)
• Moderate emetic risk IV chemotherapy: 10 mg PO the day of chemotherapy (day 1), followed by 10 mg PO qDay (days 2-3)

References

• J Clin Oncol 2017 Jul 31 (ASCO clinical practice guideline update) Support Care Cancer 2017;25(2):607-613 N Engl J Med 2016;375(2):134-42

Dosing Modifications

Renal impairment: Dose adjustment not necessary

Hepatic impairment: Dose adjustment may be necessary; use caution

Slow metabolism, initial dose for schizophrenia

• Initiate with 5 mg PO qDay for patients with risk factors which may slow olanzapine metabolism (eg, nonsmoking females ≥65 yr)
• Dose escalation should performed with caution

Dosing Considerations

Dosage adjustments, if necessary, should be made at intervals >24 hr

Bipolar I Disorder (Manic or Mixed Episodes)

<13 years: Safety and efficacy not established

13-17 years: 2.5-5 mg/day PO initially; target dosage, 10 mg/day; adjust by increments/decrements of 2.5-5 mg; dosage range, 2.5-20 mg/day

Schizophrenia

<13 years: Safety and efficacy not established

13-17 years: 2.5-5 mg/day PO initially; target dosage, 10 mg/day; adjust by increments/decrements of 2.5-5 mg; dosage range, 2.5-20 mg/day

Bipolar Depression

Indicated for depressive episodes associated with bipolar I disorder in combination with fluoxetine

<10 years: Safety and efficacy not established

10-17 years: 2.5 mg PO qPM and fluoxetine 20 mg PO qPM initially; dosage adjustments, if indicated, should be made to individual components according to efficacy and tolerability

Safety of coadministered doses greater than olanzapine 12 mg with fluoxetine 50 mg have not been in pediatric clinical studies

Stuttering (Off-label)

≤12 years: 1.25 mg PO at bedtime for 4 weeks, then 2.5 mg at bedtime

>12 years: 2.5 mg PO at bedtime for 4 weeks, then 5 mg at bedtime

Not approved for dementia-related psychosis, because of increased risk of cardiovascular or infection-related mortality (see Black Box Warnings)

Consider lower starting dosage

Schizophrenia

2.5-5 mg/day PO initially

IM (extended-release): 150 mg every 4 weeks in patients who are debilitated or predisposed to hypotensive episodes; not studied in patients with renal or hepatic impairment; requires deep IM administration (muscle mass in elderly may be sufficient)

Schizophrenia or Bipolar-Related Agitation

IM (short-acting): 5 mg; consider 2.5 mg if patient is predisposed to hypotensive reactions

Contraindicated (1)

• amisulpride

  amisulpride, olanzapine. Either increases toxicity of the other by Other (see comment). Contraindicated. Comment: Increases risk of neuroleptic malignant syndromeIncreases risk of neuroleptic malignant syndrome.

Serious - Use Alternative (51)

• abametapir

  abametapir will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP1A2 substrates. If not feasible, avoid use of abametapir.

• amisulpride

  amisulpride and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• apomorphine

  olanzapine decreases effects of apomorphine by pharmacodynamic antagonism. Avoid or Use Alternate Drug.
  
  apomorphine and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• artemether

  artemether and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• benzhydrocodone/acetaminophen

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

• bromocriptine

  olanzapine decreases effects of bromocriptine by pharmacodynamic antagonism. Avoid or Use Alternate Drug.

• cabergoline

  olanzapine decreases effects of cabergoline by pharmacodynamic antagonism. Contraindicated.

• calcium/magnesium/potassium/sodium oxybates

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

• ceritinib

  ceritinib and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• citalopram

  citalopram and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• clarithromycin

  clarithromycin and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• clozapine

  clozapine and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• crizotinib

  crizotinib and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• degarelix

  degarelix and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• desflurane

  desflurane and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• dopamine

  olanzapine decreases effects of dopamine by pharmacodynamic antagonism. Contraindicated.

• encorafenib

  encorafenib and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• entrectinib

  olanzapine and entrectinib both increase QTc interval. Avoid or Use Alternate Drug.

• erdafitinib

  olanzapine will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

• eribulin

  eribulin and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• fedratinib

  olanzapine will increase the level or effect of fedratinib by Other (see comment). Avoid or Use Alternate Drug. Avoid coadministration of fedratinib (a CYP3A4 and CYP2C19 substrate) with dual CYP3A4 and CYP2C19 inhibitor. Effect of coadministration of a dual CYP3A4 and CYP2C19 inhibitor with fedratinib has not been studied.

• fexinidazole

  fexinidazole and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to block potassium channels or prolong QT interval.

• fluvoxamine

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

• givosiran

  givosiran will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP1A2 substrates with givosiran. If unavoidable, decrease the CYP1A2 substrate dosage in accordance with approved product labeling.

• glasdegib

  olanzapine and glasdegib both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, monitor for increased risk of QTc interval prolongation.

• hydrocodone

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

• hydroxychloroquine sulfate

  hydroxychloroquine sulfate and olanzapine both increase QTc interval. Avoid or Use Alternate Drug.

• ivosidenib

  ivosidenib and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of QTc prolonging drugs with ivosidenib or replace with alternate therapies. If coadministration of a QTc prolonging drug is unavoidable, monitor for increased risk of QTc interval prolongation.

• lefamulin

  lefamulin and olanzapine both increase QTc interval. Avoid or Use Alternate Drug.

• levodopa

  olanzapine decreases effects of levodopa by pharmacodynamic antagonism. Avoid or Use Alternate Drug.

• levodopa inhaled

  olanzapine decreases effects of levodopa inhaled by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Atypical (2nd generation) antipsychotics inhibit dopamine D2 receptors in varying degrees (clozapine and quetiapine are lower risk). .

• lisuride

  olanzapine decreases effects of lisuride by pharmacodynamic antagonism. Contraindicated.

• lonafarnib

  olanzapine will increase the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of lonafarnib (a sensitive CYP3A substrate) with weak CYP3A inhibitors is unavoidable, reduce to, or continue lonafarnib at starting dose. Closely monitor for arrhythmias and events (eg, syncope, heart palpitations) since lonafarnib effect on QT interval is unknown.

• macimorelin

  macimorelin and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Macimorelin causes an increase of ~11 msec in the corrected QT interval. Avoid coadministration with drugs that prolong QT interval, which could increase risk for developing torsade de pointes-type ventricular tachycardia. Allow sufficient washout time of drugs that are known to prolong the QT interval before administering macimorelin.

• mefloquine

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

• methyldopa

  olanzapine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.

• metoclopramide intranasal

  olanzapine, metoclopramide intranasal. Either increases effects of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid use of metoclopramide intranasal or interacting drug, depending on importance of drug to patient.
  
  olanzapine increases toxicity of metoclopramide intranasal by pharmacodynamic synergism. Avoid or Use Alternate Drug. Potential for additive effects, including increased frequency and severity of tardive dyskinesia, other extrapyramidal symptoms, and neuroleptic malignant syndrome.

• mobocertinib

  mobocertinib and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, reduce mobocertinib dose and monitor QTc interval more frequently.

• ondansetron

  olanzapine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

• pefloxacin

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

• pitolisant

  olanzapine and pitolisant both increase QTc interval. Avoid or Use Alternate Drug.

• pramipexole

  olanzapine decreases effects of pramipexole by pharmacodynamic antagonism. Contraindicated.

• ribociclib

  ribociclib increases toxicity of olanzapine by QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances.

• ropinirole

  olanzapine decreases effects of ropinirole by pharmacodynamic antagonism. Contraindicated.

• safinamide

  olanzapine decreases effects of safinamide by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Dopamine antagonists may decrease safinamide effects and exacerbate Parkinson disease symptoms.

• selinexor

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

• siponimod

  olanzapine will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• sodium oxybate

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

• sufentanil SL

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

• umeclidinium bromide/vilanterol inhaled

  olanzapine increases toxicity of umeclidinium bromide/vilanterol inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

• vilanterol/fluticasone furoate inhaled

  olanzapine increases toxicity of vilanterol/fluticasone furoate inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

Monitor Closely (341)

• abobotulinumtoxinA

  abobotulinumtoxinA increases effects of olanzapine by pharmacodynamic synergism. Use Caution/Monitor. Use of anticholinergic drugs after administration of botulinum toxin-containing products may potentiate systemic anticholinergic effects.

• acarbose

  olanzapine, acarbose. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• aclidinium

  aclidinium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  aclidinium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of aclidinium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• albiglutide

  olanzapine, albiglutide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• albuterol

  olanzapine increases and albuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  albuterol and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• alfentanil

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

• alfuzosin

  olanzapine and alfuzosin both increase QTc interval. Use Caution/Monitor.
  
  alfuzosin and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• almotriptan

  almotriptan, 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).

• alprazolam

  alprazolam and olanzapine both increase sedation. Use Caution/Monitor.

• amifostine

  amifostine, olanzapine. Either increases effects of the other by anti-hypertensive channel blocking. Use Caution/Monitor. Due to its alpha adrenergic antagonism, atypical antipsychotic agents has the potential to enhance the effect of certain antihypertensive agents. Monitor blood pressure and adjust dose accordingly.

• amitriptyline

  olanzapine and amitriptyline both increase sedation. Use Caution/Monitor.

• amobarbital

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

• amoxapine

  olanzapine and amoxapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and amoxapine both increase sedation. Use Caution/Monitor.

• anticholinergic/sedative combos

  anticholinergic/sedative combos decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  anticholinergic/sedative combos decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of anticholinergic/sedative combos by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• apomorphine

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

• arformoterol

  olanzapine increases and arformoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  arformoterol and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• aripiprazole

  aripiprazole and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  aripiprazole and olanzapine both increase sedation. Use Caution/Monitor.
  
  aripiprazole and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• armodafinil

  armodafinil will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  olanzapine increases and armodafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• atomoxetine

  atomoxetine and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• atracurium

  atracurium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atracurium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of atracurium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• atropine

  atropine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atropine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of atropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• atropine IV/IM

  olanzapine increases effects of atropine IV/IM by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  atropine IV/IM decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atropine IV/IM decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.

• avapritinib

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

• axitinib

  olanzapine increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• azelastine

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

• azithromycin

  azithromycin increases toxicity of olanzapine by QTc interval. Use Caution/Monitor.

• baclofen

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

• bedaquiline

  olanzapine and bedaquiline both increase QTc interval. Modify Therapy/Monitor Closely. ECG should be monitored closely

• belladonna alkaloids

  belladonna alkaloids decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  belladonna alkaloids decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of belladonna alkaloids by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• belladonna and opium

  belladonna and opium and olanzapine both increase sedation. Use Caution/Monitor.
  
  belladonna and opium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  belladonna and opium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of belladonna and opium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• benazepril

  olanzapine, benazepril. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Enhanced hypotensive effects.

• benperidol

  benperidol and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  benperidol and olanzapine both increase sedation. Use Caution/Monitor.

• benzphetamine

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

• benztropine

  olanzapine increases effects of benztropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic adverse effects may be seen with concurrent use. .

• brexanolone

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

• brompheniramine

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

• buprenorphine

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

• buprenorphine buccal

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

• buprenorphine, long-acting injection

  olanzapine increases toxicity of buprenorphine, long-acting injection by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of buprenorphine and benzodiazepines or other CNS depressants increases risk of adverse reactions including overdose, respiratory depression, and death. Cessation of benzodiazepines or other CNS depressants is preferred in most cases. In some cases, monitoring at a higher level of care for tapering CNS depressants may be appropriate. In others, gradually tapering a patient off of a prescribed benzodiazepine or other CNS depressant or decreasing to the lowest effective dose may be appropriate.

• butabarbital

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

• butalbital

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

• butorphanol

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

• caffeine

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

• cannabidiol

  cannabidiol, olanzapine. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Owing to the potential for both CYP1A2 induction and inhibition with the coadministration of CYP1A2 substrates and cannabidiol, consider reducing dosage adjustment of CYP1A2 substrates as clinically appropriate.

• captopril

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

• carbamazepine

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

• carbinoxamine

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

• carisoprodol

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

• chloral hydrate

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

• chlordiazepoxide

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

• chloroquine

  chloroquine increases toxicity of olanzapine by QTc interval. Use Caution/Monitor.

• chlorpheniramine

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

• chlorpromazine

  chlorpromazine and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and olanzapine both increase sedation. Use Caution/Monitor.

• chlorpropamide

  olanzapine, chlorpropamide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• chlorzoxazone

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

• cigarette smoking

  cigarette smoking will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• cimetidine

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

• cinnarizine

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

• ciprofloxacin

  ciprofloxacin will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. Olanzapine plasma concentrations may be elevated, increasing the risk of adverse reactions such as orthostatic hypotension or sedation. It is important to use caution and observe patient and adjust the olanzapine dosage as needed.

• cisatracurium

  cisatracurium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  cisatracurium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of cisatracurium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• clemastine

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

• clobazam

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

• clomipramine

  olanzapine and clomipramine both increase sedation. Use Caution/Monitor.

• clonazepam

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

• clonidine

  clonidine, olanzapine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects; potential delirium.

• clorazepate

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

• clozapine

  clozapine and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  clozapine and olanzapine both increase sedation. Use Caution/Monitor.

• codeine

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

• cyclizine

  cyclizine and olanzapine both increase sedation. Use Caution/Monitor.
  
  cyclizine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  cyclizine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of cyclizine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• cyclobenzaprine

  cyclobenzaprine and olanzapine both increase sedation. Use Caution/Monitor.
  
  cyclobenzaprine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  cyclobenzaprine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of cyclobenzaprine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• cyproheptadine

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

• dantrolene

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

• daridorexant

  olanzapine and daridorexant both increase sedation. Modify Therapy/Monitor Closely. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.

• darifenacin

  darifenacin decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• dasatinib

  dasatinib and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• deferasirox

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

• desipramine

  olanzapine and desipramine both increase sedation. Use Caution/Monitor.

• deutetrabenazine

  olanzapine and deutetrabenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Modify Therapy/Monitor Closely. The risk for parkinsonism, neuroleptic malignant syndrome, and akathisia may be increased by concomitant use of deutetrabenazine and dopamine antagonists or antipsychotics.
  
  olanzapine and deutetrabenazine both increase sedation. Use Caution/Monitor.
  
  deutetrabenazine and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• dexchlorpheniramine

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

• dexfenfluramine

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

• dexmedetomidine

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

• dexmethylphenidate

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

• dextroamphetamine

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

• dextromethorphan

  dextromethorphan, 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).

• dextromoramide

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

• diamorphine

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

• diazepam

  diazepam and olanzapine both increase sedation. Use Caution/Monitor.

• dicyclomine

  dicyclomine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  dicyclomine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of dicyclomine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• diethylpropion

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

• difelikefalin

  difelikefalin and olanzapine both increase sedation. Use Caution/Monitor.

• difenoxin hcl

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

• dihydroergotamine

  dihydroergotamine, 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).

• dimenhydrinate

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

• diphenhydramine

  diphenhydramine and olanzapine both increase sedation. Use Caution/Monitor.
  
  diphenhydramine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  diphenhydramine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• diphenoxylate hcl

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

• dipipanone

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

• dobutamine

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

• dofetilide

  dofetilide increases toxicity of olanzapine by QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances.

• dolasetron

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

• donepezil

  donepezil and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• dopamine

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

• dopexamine

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

• dosulepin

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

• doxepin

  olanzapine and doxepin both increase sedation. Use Caution/Monitor.
  
  doxepin and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• doxylamine

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

• droperidol

  droperidol and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  droperidol and olanzapine both increase sedation. Use Caution/Monitor.

• efavirenz

  efavirenz and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• eletriptan

  eletriptan, 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).

• ephedrine

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

• epinephrine

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

• epinephrine racemic

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

• ergoloid mesylates

  ergoloid mesylates, 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).

• ergotamine

  ergotamine, 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).

• erythromycin base

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

• erythromycin ethylsuccinate

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

• erythromycin lactobionate

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

• erythromycin stearate

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

• escitalopram

  escitalopram increases toxicity of olanzapine by QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances.

• esketamine intranasal

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

• estazolam

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

• ethanol

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

• ethinylestradiol

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

• exenatide injectable solution

  olanzapine, exenatide injectable solution. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• exenatide injectable suspension

  olanzapine, exenatide injectable suspension. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• fenfluramine

  olanzapine increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  olanzapine decreases effects of fenfluramine by pharmacodynamic antagonism. Use Caution/Monitor. Potent serotonin receptor antagonists may decrease fenfluramine efficacy. If coadministered, monitor appropriately.

• fentanyl

  fentanyl, 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).

• fesoterodine

  fesoterodine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  fesoterodine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of fesoterodine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• fexinidazole

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

• finerenone

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

• fingolimod

  fingolimod and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• flavoxate

  flavoxate decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  flavoxate decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of flavoxate by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• flibanserin

  olanzapine will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increased flibanserin adverse effects may occur if coadministered with multiple weak CYP3A4 inhibitors.
  
  flibanserin, 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).

• fluphenazine

  fluphenazine and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  fluphenazine and olanzapine both increase sedation. Use Caution/Monitor.

• flurazepam

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

• formoterol

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

• fostemsavir

  olanzapine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.

• frovatriptan

  frovatriptan, 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).

• gadobenate

  gadobenate and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• gemifloxacin

  gemifloxacin and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• glimepiride

  olanzapine, glimepiride. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• glipizide

  olanzapine, glipizide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• glyburide

  olanzapine, glyburide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• glycopyrrolate

  olanzapine increases effects of glycopyrrolate by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• glycopyrrolate inhaled

  glycopyrrolate inhaled decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  glycopyrrolate inhaled decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of glycopyrrolate inhaled by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• guanfacine

  guanfacine, olanzapine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects; potential delirium.

• haloperidol

  haloperidol and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  haloperidol and olanzapine both increase sedation. Use Caution/Monitor.
  
  haloperidol and olanzapine both increase QTc interval. Use Caution/Monitor.

• henbane

  henbane decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  henbane decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of henbane by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• homatropine

  homatropine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  homatropine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of homatropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• hydromorphone

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

• hydroxyzine

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

• hyoscyamine

  hyoscyamine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  hyoscyamine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of hyoscyamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• hyoscyamine spray

  olanzapine increases effects of hyoscyamine spray by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  hyoscyamine spray decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  hyoscyamine spray decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.

• iloperidone

  iloperidone and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  iloperidone and olanzapine both increase sedation. Use Caution/Monitor.

• imipramine

  olanzapine and imipramine both increase sedation. Use Caution/Monitor.

• incobotulinumtoxinA

  olanzapine increases effects of incobotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• insulin aspart

  olanzapine, insulin aspart. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• insulin degludec

  olanzapine decreases effects of insulin degludec by Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; dose of antidiabetic agents may need adjustment and increased frequency of glucose monitoring may be required.

• insulin degludec/insulin aspart

  olanzapine decreases effects of insulin degludec/insulin aspart by Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; dose of antidiabetic agents may need adjustment and increased frequency of glucose monitoring may be required.

• insulin detemir

  olanzapine, insulin detemir. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• insulin glargine

  olanzapine, insulin glargine. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• insulin glulisine

  olanzapine, insulin glulisine. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• insulin inhaled

  olanzapine decreases effects of insulin inhaled by Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; dose of antidiabetic agents may need adjustment and increased frequency of glucose monitoring may be required.

• insulin lispro

  olanzapine, insulin lispro. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• insulin NPH

  olanzapine, insulin NPH. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• insulin regular human

  olanzapine, insulin regular human. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• ipratropium

  ipratropium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  ipratropium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of ipratropium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• isavuconazonium sulfate

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

• isoniazid

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

• isoproterenol

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

• ivacaftor

  olanzapine increases levels of ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor when coadministered with weak CYP3A4 inhibitors .

• ketotifen, ophthalmic

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

• lasmiditan

  lasmiditan, olanzapine. 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.

• lemborexant

  olanzapine will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Lower nightly dose of lemborexant recommended if coadministered with weak CYP3A4 inhibitors. See drug monograph for specific dosage modification.
  
  lemborexant, olanzapine. 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.

• levalbuterol

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

• levomilnacipran

  levomilnacipran, 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).

• levorphanol

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

• linezolid

  linezolid, 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).

• liraglutide

  olanzapine, liraglutide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• lisdexamfetamine

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

• lithium

  lithium, 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).

• lofepramine

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

• lofexidine

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

• lomitapide

  olanzapine increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lomitapide dose should not exceed 30 mg/day.

• loprazolam

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

• lorazepam

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

• lorcaserin

  lorcaserin, 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).

• lormetazepam

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

• loxapine

  loxapine and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  loxapine and olanzapine both increase sedation. Use Caution/Monitor.

• loxapine inhaled

  loxapine inhaled and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  loxapine inhaled and olanzapine both increase sedation. Use Caution/Monitor.

• lurasidone

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

• maprotiline

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

• maraviroc

  maraviroc, olanzapine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of orthostatic hypotension.

• marijuana

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

• meclizine

  meclizine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  meclizine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of meclizine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• melatonin

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

• meperidine

  meperidine and olanzapine both increase sedation. Use Caution/Monitor.
  
  meperidine, 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).

• meprobamate

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

• metaproterenol

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

• metaxalone

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

• metformin

  olanzapine, metformin. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• methadone

  methadone and olanzapine both increase sedation. Use Caution/Monitor.
  
  methadone, 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).

• methamphetamine

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

• methocarbamol

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

• methscopolamine

  methscopolamine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  methscopolamine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of methscopolamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• methylenedioxymethamphetamine

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

• methylergonovine

  methylergonovine, 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).

• methylphenidate

  olanzapine increases toxicity of methylphenidate by pharmacodynamic antagonism. Use Caution/Monitor. Closely monitor for signs of altered clinical response to either methylphenidate or an antipsychotic when using these drugs in combination.

• metoclopramide

  olanzapine and metoclopramide both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.

• mexiletine

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

• midazolam

  midazolam and olanzapine both increase sedation. Use Caution/Monitor.

• midazolam intranasal

  olanzapine will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of mild CYP3A4 inhibitors with midazolam intranasal may cause higher midazolam systemic exposure, which may prolong sedation.
  
  midazolam intranasal, olanzapine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase the risk of hypoventilation, airway obstruction, desaturation, or apnea and may contribute to profound and/or prolonged drug effect.

• midodrine

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

• mifepristone

  mifepristone, olanzapine. QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available.

• miglitol

  olanzapine, miglitol. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• milnacipran

  milnacipran, 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).

• mirtazapine

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

• modafinil

  modafinil will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  olanzapine increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• morphine

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

• motherwort

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

• moxonidine

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

• nabilone

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

• nalbuphine

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

• naratriptan

  naratriptan, 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).

• nateglinide

  olanzapine, nateglinide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• norepinephrine

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

• nortriptyline

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

• oliceridine

  oliceridine, olanzapine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• onabotulinumtoxinA

  onabotulinumtoxinA decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  onabotulinumtoxinA decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of onabotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• opium tincture

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

• orphenadrine

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

• osilodrostat

  osilodrostat and olanzapine both increase QTc interval. Use Caution/Monitor.

• osimertinib

  osimertinib and olanzapine both increase QTc interval. Use Caution/Monitor. Conduct periodic monitoring with ECGs and electrolytes in patients taking drugs known to prolong the QTc interval.

• oxaliplatin

  oxaliplatin will increase the level or effect of olanzapine by Other (see comment). Use Caution/Monitor. Monitor for ECG changes if therapy is initiated in patients with drugs known to prolong QT interval.

• oxazepam

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

• oxybutynin

  oxybutynin decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of oxybutynin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• oxybutynin topical

  oxybutynin topical decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin topical decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of oxybutynin topical by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• oxybutynin transdermal

  oxybutynin transdermal decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin transdermal decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• oxycodone

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

• oxymorphone

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

• ozanimod

  ozanimod and olanzapine both increase QTc interval. Modify Therapy/Monitor Closely. The potential additive effects on heart rate, treatment with ozanimod should generally not be initiated in patients who are concurrently treated with QT prolonging drugs with known arrhythmogenic properties.

• paliperidone

  olanzapine and paliperidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and paliperidone both increase sedation. Use Caution/Monitor.

• pancuronium

  pancuronium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  pancuronium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of pancuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• papaveretum

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

• papaverine

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

• paroxetine

  paroxetine, 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).

• pasireotide

  olanzapine and pasireotide both increase QTc interval. Modify Therapy/Monitor Closely.

• peginterferon alfa 2a

  peginterferon alfa 2a will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• pentazocine

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

• pentobarbital

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

• perphenazine

  olanzapine and perphenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and perphenazine both increase sedation. Use Caution/Monitor.

• phendimetrazine

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

• phenelzine

  phenelzine, 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).

• phenobarbital

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

• phentermine

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

• phenylephrine

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

• phenylephrine PO

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

• pholcodine

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

• pimozide

  olanzapine and pimozide both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and pimozide both increase sedation. Use Caution/Monitor.

• pioglitazone

  olanzapine, pioglitazone. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• pipemidic acid

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

• pirbuterol

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

• pralidoxime

  pralidoxime decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  pralidoxime decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of pralidoxime by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• pramlintide

  olanzapine, pramlintide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• primidone

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

• procarbazine

  procarbazine, 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).

• prochlorperazine

  olanzapine and prochlorperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and prochlorperazine both increase sedation. Use Caution/Monitor.

• promethazine

  olanzapine and promethazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  promethazine and olanzapine both increase sedation. Use Caution/Monitor.
  
  promethazine, 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).

• propantheline

  propantheline decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  propantheline decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of propantheline by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• propofol

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

• propylhexedrine

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

• protriptyline

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

• quazepam

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

• quetiapine

  olanzapine and quetiapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and quetiapine both increase sedation. Use Caution/Monitor.

• quinine

  olanzapine and quinine both increase QTc interval. Use Caution/Monitor.

• ramelteon

  olanzapine and ramelteon both increase sedation. Use Caution/Monitor.

• rapacuronium

  rapacuronium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  rapacuronium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of rapacuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• remimazolam

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

• repaglinide

  olanzapine, repaglinide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• rifampin

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

• rimabotulinumtoxinB

  olanzapine, rimabotulinumtoxinB. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Anticholinergics may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.

• risperidone

  olanzapine and risperidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and risperidone both increase sedation. Use Caution/Monitor.

• ritonavir

  ritonavir decreases levels of olanzapine by increasing metabolism. Use Caution/Monitor.

• rocuronium

  rocuronium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  rocuronium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of rocuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• rosiglitazone

  olanzapine, rosiglitazone. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• rucaparib

  rucaparib will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP1A2 substrates, if clinically indicated.

• salmeterol

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

• saxagliptin

  olanzapine, saxagliptin. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• scopolamine

  scopolamine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  scopolamine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of scopolamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• scullcap

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

• secobarbital

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

• selegiline

  selegiline, 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).

• selpercatinib

  selpercatinib increases toxicity of olanzapine by QTc interval. Use Caution/Monitor.

• shepherd's purse

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

• sitagliptin

  olanzapine, sitagliptin. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• smoking

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

• sodium sulfate/?magnesium sulfate/potassium chloride

  sodium sulfate/?magnesium sulfate/potassium chloride increases effects of olanzapine by unknown mechanism. Use Caution/Monitor. Closely monitor for evidence of enhanced CNS depression when using higher dose of magnesium sulfate together with a CNS depressant.

• sodium sulfate/potassium sulfate/magnesium sulfate

  sodium sulfate/potassium sulfate/magnesium sulfate increases effects of olanzapine by unknown mechanism. Use Caution/Monitor. Closely monitor for evidence of enhanced CNS depression when using higher dose of magnesium sulfate together with a CNS depressant.

• solifenacin

  solifenacin decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  solifenacin decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of solifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• sorafenib

  sorafenib and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• stiripentol

  stiripentol, olanzapine. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP1A2 inhibitor and inducer. Monitor CYP1A2 substrates coadministered with stiripentol for increased or decreased effects. CYP1A2 substrates may require dosage adjustment.
  
  stiripentol, olanzapine. Either increases effects of the other by sedation. Use Caution/Monitor. Concomitant use stiripentol with other CNS depressants, including alcohol, may increase the risk of sedation and somnolence.

• sufentanil

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

• sumatriptan

  sumatriptan, 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).

• sumatriptan intranasal

  sumatriptan intranasal, 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).

• tapentadol

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

• tazemetostat

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

• temazepam

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

• terbutaline

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

• teriflunomide

  teriflunomide decreases levels of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• tetrabenazine

  olanzapine and tetrabenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Modify Therapy/Monitor Closely.

• thioridazine

  olanzapine and thioridazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and thioridazine both increase sedation. Use Caution/Monitor.

• thiothixene

  olanzapine and thiothixene both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and thiothixene both increase sedation. Use Caution/Monitor.

• tinidazole

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

• tiotropium

  tiotropium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  tiotropium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of tiotropium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• tobacco use

  tobacco use will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• tolazamide

  olanzapine, tolazamide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• tolbutamide

  olanzapine, tolbutamide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• tolterodine

  tolterodine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  tolterodine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of tolterodine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• topiramate

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

• tramadol

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

• tranylcypromine

  tranylcypromine, 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).

• trazodone

  olanzapine and trazodone both increase sedation. Use Caution/Monitor.

• triazolam

  triazolam and olanzapine both increase sedation. Use Caution/Monitor.

• triclabendazole

  triclabendazole and olanzapine both increase QTc interval. Use Caution/Monitor.

• triclofos

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

• trifluoperazine

  olanzapine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and trifluoperazine both increase sedation. Use Caution/Monitor.

• trihexyphenidyl

  olanzapine increases effects of trihexyphenidyl by pharmacodynamic synergism. Use Caution/Monitor. Potential for additive anticholinergic effects.

• trimipramine

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

• triprolidine

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

• trospium chloride

  trospium chloride decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  trospium chloride decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of trospium chloride by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• vecuronium

  vecuronium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  vecuronium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of vecuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• venlafaxine

  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).

• verapamil

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

• vilazodone

  vilazodone, 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).

• voclosporin

  voclosporin, olanzapine. Either increases effects of the other by QTc interval. Use Caution/Monitor.

• xylometazoline

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

• yohimbine

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

• ziconotide

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

• zileuton

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

• ziprasidone

  olanzapine and ziprasidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and ziprasidone both increase sedation. Use Caution/Monitor.

• zolmitriptan

  zolmitriptan, 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).

• zotepine

  olanzapine and zotepine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and zotepine both increase sedation. Use Caution/Monitor.

Minor (8)

• brimonidine

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

• chasteberry

  chasteberry decreases effects of olanzapine by pharmacodynamic antagonism. Minor/Significance Unknown. (Theoretical interaction).

• ethanol

  ethanol, olanzapine. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive CNS depression.

• eucalyptus

  olanzapine and eucalyptus both increase sedation. Minor/Significance Unknown.

• omeprazole

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

• ruxolitinib

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

• ruxolitinib topical

  olanzapine will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• sage

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

• abametapir

  Serious - Use Alternative (1)abametapir will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP1A2 substrates. If not feasible, avoid use of abametapir.

• abobotulinumtoxinA

  Monitor Closely (1)abobotulinumtoxinA increases effects of olanzapine by pharmacodynamic synergism. Use Caution/Monitor. Use of anticholinergic drugs after administration of botulinum toxin-containing products may potentiate systemic anticholinergic effects.

• acarbose

  Monitor Closely (1)olanzapine, acarbose. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• aclidinium

  Monitor Closely (3)aclidinium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  aclidinium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of aclidinium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• albiglutide

  Monitor Closely (1)olanzapine, albiglutide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• albuterol

  Monitor Closely (2)albuterol and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances
  
  olanzapine increases and albuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• alfentanil

  Monitor Closely (1)alfentanil and olanzapine both increase sedation. Use Caution/Monitor.

• alfuzosin

  Monitor Closely (2)olanzapine and alfuzosin both increase QTc interval. Use Caution/Monitor.
  
  alfuzosin and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• almotriptan

  Monitor Closely (1)almotriptan, 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).

• alprazolam

  Monitor Closely (1)alprazolam and olanzapine both increase sedation. Use Caution/Monitor.

• amifostine

  Monitor Closely (1)amifostine, olanzapine. Either increases effects of the other by anti-hypertensive channel blocking. Use Caution/Monitor. Due to its alpha adrenergic antagonism, atypical antipsychotic agents has the potential to enhance the effect of certain antihypertensive agents. Monitor blood pressure and adjust dose accordingly.

• amisulpride

  Contraindicated (1)amisulpride, olanzapine. Either increases toxicity of the other by Other (see comment). Contraindicated. Comment: Increases risk of neuroleptic malignant syndromeIncreases risk of neuroleptic malignant syndrome.Serious - Use Alternative (1)amisulpride and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• amitriptyline

  Monitor Closely (1)olanzapine and amitriptyline both increase sedation. Use Caution/Monitor.

• amobarbital

  Monitor Closely (2)amobarbital will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  amobarbital and olanzapine both increase sedation. Use Caution/Monitor.

• amoxapine

  Monitor Closely (2)olanzapine and amoxapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and amoxapine both increase sedation. Use Caution/Monitor.

• anticholinergic/sedative combos

  Monitor Closely (3)anticholinergic/sedative combos decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  anticholinergic/sedative combos decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of anticholinergic/sedative combos by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• apomorphine

  Monitor Closely (1)olanzapine and apomorphine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (2)olanzapine decreases effects of apomorphine by pharmacodynamic antagonism. Avoid or Use Alternate Drug.
  
  apomorphine and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• arformoterol

  Monitor Closely (2)arformoterol and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances
  
  olanzapine increases and arformoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• aripiprazole

  Monitor Closely (3)aripiprazole and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances
  
  aripiprazole and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  aripiprazole and olanzapine both increase sedation. Use Caution/Monitor.

• armodafinil

  Monitor Closely (2)armodafinil will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  olanzapine increases and armodafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• artemether

  Serious - Use Alternative (1)artemether and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• atomoxetine

  Monitor Closely (1)atomoxetine and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• atracurium

  Monitor Closely (3)atracurium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atracurium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of atracurium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• atropine

  Monitor Closely (3)atropine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atropine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of atropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• atropine IV/IM

  Monitor Closely (3)olanzapine increases effects of atropine IV/IM by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  atropine IV/IM decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atropine IV/IM decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.

• avapritinib

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

• axitinib

  Monitor Closely (1)olanzapine increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• azelastine

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

• azithromycin

  Monitor Closely (1)azithromycin increases toxicity of olanzapine by QTc interval. Use Caution/Monitor.

• baclofen

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

• bedaquiline

  Monitor Closely (1)olanzapine and bedaquiline both increase QTc interval. Modify Therapy/Monitor Closely. ECG should be monitored closely

• belladonna alkaloids

  Monitor Closely (3)belladonna alkaloids decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  belladonna alkaloids decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of belladonna alkaloids by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• belladonna and opium

  Monitor Closely (4)belladonna and opium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  belladonna and opium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of belladonna and opium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  belladonna and opium and olanzapine both increase sedation. Use Caution/Monitor.

• benazepril

  Monitor Closely (1)olanzapine, benazepril. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Enhanced hypotensive effects.

• benperidol

  Monitor Closely (2)benperidol and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  benperidol and olanzapine both increase sedation. Use Caution/Monitor.

• benzhydrocodone/acetaminophen

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

• benzphetamine

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

• benztropine

  Monitor Closely (1)olanzapine increases effects of benztropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic adverse effects may be seen with concurrent use. .

• brexanolone

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

• brimonidine

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

• bromocriptine

  Serious - Use Alternative (1)olanzapine decreases effects of bromocriptine by pharmacodynamic antagonism. Avoid or Use Alternate Drug.

• brompheniramine

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

• buprenorphine

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

• buprenorphine buccal

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

• buprenorphine, long-acting injection

  Monitor Closely (1)olanzapine increases toxicity of buprenorphine, long-acting injection by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of buprenorphine and benzodiazepines or other CNS depressants increases risk of adverse reactions including overdose, respiratory depression, and death. Cessation of benzodiazepines or other CNS depressants is preferred in most cases. In some cases, monitoring at a higher level of care for tapering CNS depressants may be appropriate. In others, gradually tapering a patient off of a prescribed benzodiazepine or other CNS depressant or decreasing to the lowest effective dose may be appropriate.

• butabarbital

  Monitor Closely (2)butabarbital will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  butabarbital and olanzapine both increase sedation. Use Caution/Monitor.

• butalbital

  Monitor Closely (2)butalbital will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  butalbital and olanzapine both increase sedation. Use Caution/Monitor.

• butorphanol

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

• cabergoline

  Serious - Use Alternative (1)olanzapine decreases effects of cabergoline by pharmacodynamic antagonism. Contraindicated.

• caffeine

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

• calcium/magnesium/potassium/sodium oxybates

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

• cannabidiol

  Monitor Closely (1)cannabidiol, olanzapine. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Owing to the potential for both CYP1A2 induction and inhibition with the coadministration of CYP1A2 substrates and cannabidiol, consider reducing dosage adjustment of CYP1A2 substrates as clinically appropriate.

• captopril

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

• carbamazepine

  Monitor Closely (1)carbamazepine will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• carbinoxamine

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

• carisoprodol

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

• ceritinib

  Serious - Use Alternative (1)ceritinib and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• chasteberry

  Minor (1)chasteberry decreases effects of olanzapine by pharmacodynamic antagonism. Minor/Significance Unknown. (Theoretical interaction).

• chloral hydrate

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

• chlordiazepoxide

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

• chloroquine

  Monitor Closely (1)chloroquine increases toxicity of olanzapine by QTc interval. Use Caution/Monitor.

• chlorpheniramine

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

• chlorpromazine

  Monitor Closely (2)chlorpromazine and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and olanzapine both increase sedation. Use Caution/Monitor.

• chlorpropamide

  Monitor Closely (1)olanzapine, chlorpropamide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• chlorzoxazone

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

• cigarette smoking

  Monitor Closely (1)cigarette smoking will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• cimetidine

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

• cinnarizine

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

• ciprofloxacin

  Monitor Closely (1)ciprofloxacin will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. Olanzapine plasma concentrations may be elevated, increasing the risk of adverse reactions such as orthostatic hypotension or sedation. It is important to use caution and observe patient and adjust the olanzapine dosage as needed.

• cisatracurium

  Monitor Closely (3)cisatracurium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  cisatracurium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of cisatracurium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• citalopram

  Serious - Use Alternative (1)citalopram and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• clarithromycin

  Serious - Use Alternative (1)clarithromycin and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• clemastine

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

• clobazam

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

• clomipramine

  Monitor Closely (1)olanzapine and clomipramine both increase sedation. Use Caution/Monitor.

• clonazepam

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

• clonidine

  Monitor Closely (1)clonidine, olanzapine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects; potential delirium.

• clorazepate

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

• clozapine

  Monitor Closely (2)clozapine and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  clozapine and olanzapine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)clozapine and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• codeine

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

• crizotinib

  Serious - Use Alternative (1)crizotinib and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• cyclizine

  Monitor Closely (4)cyclizine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  cyclizine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of cyclizine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  cyclizine and olanzapine both increase sedation. Use Caution/Monitor.

• cyclobenzaprine

  Monitor Closely (4)cyclobenzaprine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  cyclobenzaprine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of cyclobenzaprine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  cyclobenzaprine and olanzapine both increase sedation. Use Caution/Monitor.

• cyproheptadine

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

• dantrolene

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

• daridorexant

  Monitor Closely (1)olanzapine and daridorexant both increase sedation. Modify Therapy/Monitor Closely. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.

• darifenacin

  Monitor Closely (3)darifenacin decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• dasatinib

  Monitor Closely (1)dasatinib and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• deferasirox

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

• degarelix

  Serious - Use Alternative (1)degarelix and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• desflurane

  Serious - Use Alternative (1)desflurane and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• desipramine

  Monitor Closely (1)olanzapine and desipramine both increase sedation. Use Caution/Monitor.

• deutetrabenazine

  Monitor Closely (3)olanzapine and deutetrabenazine both increase sedation. Use Caution/Monitor.
  
  deutetrabenazine and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances
  
  olanzapine and deutetrabenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Modify Therapy/Monitor Closely. The risk for parkinsonism, neuroleptic malignant syndrome, and akathisia may be increased by concomitant use of deutetrabenazine and dopamine antagonists or antipsychotics.

• dexchlorpheniramine

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

• dexfenfluramine

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

• dexmedetomidine

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

• dexmethylphenidate

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

• dextroamphetamine

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

• dextromethorphan

  Monitor Closely (1)dextromethorphan, 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).

• dextromoramide

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

• diamorphine

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

• diazepam

  Monitor Closely (1)diazepam and olanzapine both increase sedation. Use Caution/Monitor.

• dicyclomine

  Monitor Closely (3)dicyclomine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  dicyclomine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of dicyclomine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• diethylpropion

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

• difelikefalin

  Monitor Closely (1)difelikefalin and olanzapine both increase sedation. Use Caution/Monitor.

• difenoxin hcl

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

• dihydroergotamine

  Monitor Closely (1)dihydroergotamine, 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).

• dimenhydrinate

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

• diphenhydramine

  Monitor Closely (4)diphenhydramine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  diphenhydramine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  diphenhydramine and olanzapine both increase sedation. Use Caution/Monitor.

• diphenoxylate hcl

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

• dipipanone

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

• dobutamine

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

• dofetilide

  Monitor Closely (1)dofetilide increases toxicity of olanzapine by QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances.

• dolasetron

  Monitor Closely (1)dolasetron and olanzapine both increase QTc interval. Use Caution/Monitor.

• donepezil

  Monitor Closely (1)donepezil and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• dopamine

  Monitor Closely (1)olanzapine increases and dopamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)olanzapine decreases effects of dopamine by pharmacodynamic antagonism. Contraindicated.

• dopexamine

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

• dosulepin

  Monitor Closely (1)olanzapine and dosulepin both increase sedation. Use Caution/Monitor.

• doxepin

  Monitor Closely (2)doxepin and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances
  
  olanzapine and doxepin both increase sedation. Use Caution/Monitor.

• doxylamine

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

• droperidol

  Monitor Closely (2)droperidol and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  droperidol and olanzapine both increase sedation. Use Caution/Monitor.

• efavirenz

  Monitor Closely (1)efavirenz and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• eletriptan

  Monitor Closely (1)eletriptan, 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).

• encorafenib

  Serious - Use Alternative (1)encorafenib and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• entrectinib

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

• ephedrine

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

• epinephrine

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

• epinephrine racemic

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

• erdafitinib

  Serious - Use Alternative (1)olanzapine will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

• ergoloid mesylates

  Monitor Closely (1)ergoloid mesylates, 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).

• ergotamine

  Monitor Closely (1)ergotamine, 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).

• eribulin

  Serious - Use Alternative (1)eribulin and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• erythromycin base

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

• erythromycin ethylsuccinate

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

• erythromycin lactobionate

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

• erythromycin stearate

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

• escitalopram

  Monitor Closely (1)escitalopram increases toxicity of olanzapine by QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances.

• esketamine intranasal

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

• estazolam

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

• ethanol

  Monitor Closely (1)olanzapine and ethanol both increase sedation. Use Caution/Monitor.Minor (1)ethanol, olanzapine. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive CNS depression.

• ethinylestradiol

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

• eucalyptus

  Minor (1)olanzapine and eucalyptus both increase sedation. Minor/Significance Unknown.

• exenatide injectable solution

  Monitor Closely (1)olanzapine, exenatide injectable solution. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• exenatide injectable suspension

  Monitor Closely (1)olanzapine, exenatide injectable suspension. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• fedratinib

  Serious - Use Alternative (1)olanzapine will increase the level or effect of fedratinib by Other (see comment). Avoid or Use Alternate Drug. Avoid coadministration of fedratinib (a CYP3A4 and CYP2C19 substrate) with dual CYP3A4 and CYP2C19 inhibitor. Effect of coadministration of a dual CYP3A4 and CYP2C19 inhibitor with fedratinib has not been studied.

• fenfluramine

  Monitor Closely (2)olanzapine decreases effects of fenfluramine by pharmacodynamic antagonism. Use Caution/Monitor. Potent serotonin receptor antagonists may decrease fenfluramine efficacy. If coadministered, monitor appropriately.
  
  olanzapine increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• fentanyl

  Monitor Closely (1)fentanyl, 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).

• fesoterodine

  Monitor Closely (3)fesoterodine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  fesoterodine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of fesoterodine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• fexinidazole

  Monitor Closely (1)fexinidazole will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)fexinidazole and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to block potassium channels or prolong QT interval.

• finerenone

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

• fingolimod

  Monitor Closely (1)fingolimod and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• flavoxate

  Monitor Closely (3)flavoxate decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  flavoxate decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of flavoxate by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• flibanserin

  Monitor Closely (2)olanzapine will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increased flibanserin adverse effects may occur if coadministered with multiple weak CYP3A4 inhibitors.
  
  flibanserin, 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).

• fluphenazine

  Monitor Closely (2)fluphenazine and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  fluphenazine and olanzapine both increase sedation. Use Caution/Monitor.

• flurazepam

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

• fluvoxamine

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

• formoterol

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

• fostemsavir

  Monitor Closely (1)olanzapine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.

• frovatriptan

  Monitor Closely (1)frovatriptan, 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).

• gadobenate

  Monitor Closely (1)gadobenate and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• gemifloxacin

  Monitor Closely (1)gemifloxacin and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• givosiran

  Serious - Use Alternative (1)givosiran will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP1A2 substrates with givosiran. If unavoidable, decrease the CYP1A2 substrate dosage in accordance with approved product labeling.

• glasdegib

  Serious - Use Alternative (1)olanzapine and glasdegib both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, monitor for increased risk of QTc interval prolongation.

• glimepiride

  Monitor Closely (1)olanzapine, glimepiride. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• glipizide

  Monitor Closely (1)olanzapine, glipizide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• glyburide

  Monitor Closely (1)olanzapine, glyburide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• glycopyrrolate

  Monitor Closely (1)olanzapine increases effects of glycopyrrolate by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• glycopyrrolate inhaled

  Monitor Closely (3)glycopyrrolate inhaled decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  glycopyrrolate inhaled decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of glycopyrrolate inhaled by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• guanfacine

  Monitor Closely (1)guanfacine, olanzapine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects; potential delirium.

• haloperidol

  Monitor Closely (3)haloperidol and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  haloperidol and olanzapine both increase sedation. Use Caution/Monitor.
  
  haloperidol and olanzapine both increase QTc interval. Use Caution/Monitor.

• henbane

  Monitor Closely (3)henbane decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  henbane decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of henbane by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• homatropine

  Monitor Closely (3)homatropine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  homatropine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of homatropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• hydrocodone

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

• hydromorphone

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

• hydroxychloroquine sulfate

  Serious - Use Alternative (1)hydroxychloroquine sulfate and olanzapine both increase QTc interval. Avoid or Use Alternate Drug.

• hydroxyzine

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

• hyoscyamine

  Monitor Closely (3)hyoscyamine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  hyoscyamine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of hyoscyamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• hyoscyamine spray

  Monitor Closely (3)olanzapine increases effects of hyoscyamine spray by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  hyoscyamine spray decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  hyoscyamine spray decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.

• iloperidone

  Monitor Closely (2)iloperidone and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  iloperidone and olanzapine both increase sedation. Use Caution/Monitor.

• imipramine

  Monitor Closely (1)olanzapine and imipramine both increase sedation. Use Caution/Monitor.

• incobotulinumtoxinA

  Monitor Closely (1)olanzapine increases effects of incobotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• insulin aspart

  Monitor Closely (1)olanzapine, insulin aspart. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• insulin degludec

  Monitor Closely (1)olanzapine decreases effects of insulin degludec by Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; dose of antidiabetic agents may need adjustment and increased frequency of glucose monitoring may be required.

• insulin degludec/insulin aspart

  Monitor Closely (1)olanzapine decreases effects of insulin degludec/insulin aspart by Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; dose of antidiabetic agents may need adjustment and increased frequency of glucose monitoring may be required.

• insulin detemir

  Monitor Closely (1)olanzapine, insulin detemir. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• insulin glargine

  Monitor Closely (1)olanzapine, insulin glargine. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• insulin glulisine

  Monitor Closely (1)olanzapine, insulin glulisine. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• insulin inhaled

  Monitor Closely (1)olanzapine decreases effects of insulin inhaled by Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; dose of antidiabetic agents may need adjustment and increased frequency of glucose monitoring may be required.

• insulin lispro

  Monitor Closely (1)olanzapine, insulin lispro. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• insulin NPH

  Monitor Closely (1)olanzapine, insulin NPH. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• insulin regular human

  Monitor Closely (1)olanzapine, insulin regular human. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• ipratropium

  Monitor Closely (3)ipratropium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  ipratropium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of ipratropium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• isavuconazonium sulfate

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

• isoniazid

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

• isoproterenol

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

• ivacaftor

  Monitor Closely (1)olanzapine increases levels of ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor when coadministered with weak CYP3A4 inhibitors .

• ivosidenib

  Serious - Use Alternative (1)ivosidenib and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of QTc prolonging drugs with ivosidenib or replace with alternate therapies. If coadministration of a QTc prolonging drug is unavoidable, monitor for increased risk of QTc interval prolongation.

• ketotifen, ophthalmic

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

• lasmiditan

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

• lefamulin

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

• lemborexant

  Monitor Closely (2)olanzapine will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Lower nightly dose of lemborexant recommended if coadministered with weak CYP3A4 inhibitors. See drug monograph for specific dosage modification.
  
  lemborexant, olanzapine. 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.

• levalbuterol

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

• levodopa

  Serious - Use Alternative (1)olanzapine decreases effects of levodopa by pharmacodynamic antagonism. Avoid or Use Alternate Drug.

• levodopa inhaled

  Serious - Use Alternative (1)olanzapine decreases effects of levodopa inhaled by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Atypical (2nd generation) antipsychotics inhibit dopamine D2 receptors in varying degrees (clozapine and quetiapine are lower risk). .

• levomilnacipran

  Monitor Closely (1)levomilnacipran, 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).

• levorphanol

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

• linezolid

  Monitor Closely (1)linezolid, 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).

• liraglutide

  Monitor Closely (1)olanzapine, liraglutide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• lisdexamfetamine

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

• lisuride

  Serious - Use Alternative (1)olanzapine decreases effects of lisuride by pharmacodynamic antagonism. Contraindicated.

• lithium

  Monitor Closely (1)lithium, 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).

• lofepramine

  Monitor Closely (1)olanzapine and lofepramine both increase sedation. Use Caution/Monitor.

• lofexidine

  Monitor Closely (1)olanzapine and lofexidine both increase sedation. Use Caution/Monitor.

• lomitapide

  Monitor Closely (1)olanzapine increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lomitapide dose should not exceed 30 mg/day.

• lonafarnib

  Serious - Use Alternative (1)olanzapine will increase the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of lonafarnib (a sensitive CYP3A substrate) with weak CYP3A inhibitors is unavoidable, reduce to, or continue lonafarnib at starting dose. Closely monitor for arrhythmias and events (eg, syncope, heart palpitations) since lonafarnib effect on QT interval is unknown.

• loprazolam

  Monitor Closely (1)loprazolam and olanzapine both increase sedation. Use Caution/Monitor.

• lorazepam

  Monitor Closely (1)lorazepam and olanzapine both increase sedation. Use Caution/Monitor.

• lorcaserin

  Monitor Closely (1)lorcaserin, 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).

• lormetazepam

  Monitor Closely (1)lormetazepam and olanzapine both increase sedation. Use Caution/Monitor.

• loxapine

  Monitor Closely (2)loxapine and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  loxapine and olanzapine both increase sedation. Use Caution/Monitor.

• loxapine inhaled

  Monitor Closely (2)loxapine inhaled and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  loxapine inhaled and olanzapine both increase sedation. Use Caution/Monitor.

• lurasidone

  Monitor Closely (1)lurasidone, olanzapine. 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.

• macimorelin

  Serious - Use Alternative (1)macimorelin and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. Macimorelin causes an increase of ~11 msec in the corrected QT interval. Avoid coadministration with drugs that prolong QT interval, which could increase risk for developing torsade de pointes-type ventricular tachycardia. Allow sufficient washout time of drugs that are known to prolong the QT interval before administering macimorelin.

• maprotiline

  Monitor Closely (1)olanzapine and maprotiline both increase sedation. Use Caution/Monitor.

• maraviroc

  Monitor Closely (1)maraviroc, olanzapine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of orthostatic hypotension.

• marijuana

  Monitor Closely (1)olanzapine and marijuana both increase sedation. Use Caution/Monitor.

• meclizine

  Monitor Closely (3)meclizine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  meclizine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of meclizine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• mefloquine

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

• melatonin

  Monitor Closely (1)olanzapine and melatonin both increase sedation. Use Caution/Monitor.

• meperidine

  Monitor Closely (2)meperidine, 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).
  
  meperidine and olanzapine both increase sedation. Use Caution/Monitor.

• meprobamate

  Monitor Closely (1)olanzapine and meprobamate both increase sedation. Use Caution/Monitor.

• metaproterenol

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

• metaxalone

  Monitor Closely (1)metaxalone and olanzapine both increase sedation. Use Caution/Monitor.

• metformin

  Monitor Closely (1)olanzapine, metformin. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• methadone

  Monitor Closely (2)methadone, 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).
  
  methadone and olanzapine both increase sedation. Use Caution/Monitor.

• methamphetamine

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

• methocarbamol

  Monitor Closely (1)methocarbamol and olanzapine both increase sedation. Use Caution/Monitor.

• methscopolamine

  Monitor Closely (3)methscopolamine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  methscopolamine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of methscopolamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• methyldopa

  Serious - Use Alternative (1)olanzapine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.

• methylenedioxymethamphetamine

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

• methylergonovine

  Monitor Closely (1)methylergonovine, 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).

• methylphenidate

  Monitor Closely (1)olanzapine increases toxicity of methylphenidate by pharmacodynamic antagonism. Use Caution/Monitor. Closely monitor for signs of altered clinical response to either methylphenidate or an antipsychotic when using these drugs in combination.

• metoclopramide

  Monitor Closely (1)olanzapine and metoclopramide both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.

• metoclopramide intranasal

  Serious - Use Alternative (2)olanzapine, metoclopramide intranasal. Either increases effects of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid use of metoclopramide intranasal or interacting drug, depending on importance of drug to patient.
  
  olanzapine increases toxicity of metoclopramide intranasal by pharmacodynamic synergism. Avoid or Use Alternate Drug. Potential for additive effects, including increased frequency and severity of tardive dyskinesia, other extrapyramidal symptoms, and neuroleptic malignant syndrome.

• mexiletine

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

• midazolam

  Monitor Closely (1)midazolam and olanzapine both increase sedation. Use Caution/Monitor.

• midazolam intranasal

  Monitor Closely (2)olanzapine will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of mild CYP3A4 inhibitors with midazolam intranasal may cause higher midazolam systemic exposure, which may prolong sedation.
  
  midazolam intranasal, olanzapine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase the risk of hypoventilation, airway obstruction, desaturation, or apnea and may contribute to profound and/or prolonged drug effect.

• midodrine

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

• mifepristone

  Monitor Closely (1)mifepristone, olanzapine. QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available.

• miglitol

  Monitor Closely (1)olanzapine, miglitol. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• milnacipran

  Monitor Closely (1)milnacipran, 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).

• mirtazapine

  Monitor Closely (1)olanzapine and mirtazapine both increase sedation. Use Caution/Monitor.

• mobocertinib

  Serious - Use Alternative (1)mobocertinib and olanzapine both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, reduce mobocertinib dose and monitor QTc interval more frequently.

• modafinil

  Monitor Closely (2)modafinil will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  olanzapine increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• morphine

  Monitor Closely (1)morphine and olanzapine both increase sedation. Use Caution/Monitor.

• motherwort

  Monitor Closely (1)olanzapine and motherwort both increase sedation. Use Caution/Monitor.

• moxonidine

  Monitor Closely (1)olanzapine and moxonidine both increase sedation. Use Caution/Monitor.

• nabilone

  Monitor Closely (1)olanzapine and nabilone both increase sedation. Use Caution/Monitor.

• nalbuphine

  Monitor Closely (1)nalbuphine and olanzapine both increase sedation. Use Caution/Monitor.

• naratriptan

  Monitor Closely (1)naratriptan, 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).

• nateglinide

  Monitor Closely (1)olanzapine, nateglinide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• norepinephrine

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

• nortriptyline

  Monitor Closely (1)olanzapine and nortriptyline both increase sedation. Use Caution/Monitor.

• oliceridine

  Monitor Closely (1)oliceridine, olanzapine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• omeprazole

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

• onabotulinumtoxinA

  Monitor Closely (3)onabotulinumtoxinA decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  onabotulinumtoxinA decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of onabotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• ondansetron

  Serious - Use Alternative (1)olanzapine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

• opium tincture

  Monitor Closely (1)opium tincture and olanzapine both increase sedation. Use Caution/Monitor.

• orphenadrine

  Monitor Closely (1)orphenadrine and olanzapine both increase sedation. Use Caution/Monitor.

• osilodrostat

  Monitor Closely (1)osilodrostat and olanzapine both increase QTc interval. Use Caution/Monitor.

• osimertinib

  Monitor Closely (1)osimertinib and olanzapine both increase QTc interval. Use Caution/Monitor. Conduct periodic monitoring with ECGs and electrolytes in patients taking drugs known to prolong the QTc interval.

• oxaliplatin

  Monitor Closely (1)oxaliplatin will increase the level or effect of olanzapine by Other (see comment). Use Caution/Monitor. Monitor for ECG changes if therapy is initiated in patients with drugs known to prolong QT interval.

• oxazepam

  Monitor Closely (1)oxazepam and olanzapine both increase sedation. Use Caution/Monitor.

• oxybutynin

  Monitor Closely (3)oxybutynin decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of oxybutynin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• oxybutynin topical

  Monitor Closely (3)oxybutynin topical decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin topical decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of oxybutynin topical by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• oxybutynin transdermal

  Monitor Closely (3)oxybutynin transdermal decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin transdermal decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• oxycodone

  Monitor Closely (1)oxycodone and olanzapine both increase sedation. Use Caution/Monitor.

• oxymorphone

  Monitor Closely (1)oxymorphone and olanzapine both increase sedation. Use Caution/Monitor.

• ozanimod

  Monitor Closely (1)ozanimod and olanzapine both increase QTc interval. Modify Therapy/Monitor Closely. The potential additive effects on heart rate, treatment with ozanimod should generally not be initiated in patients who are concurrently treated with QT prolonging drugs with known arrhythmogenic properties.

• paliperidone

  Monitor Closely (2)olanzapine and paliperidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and paliperidone both increase sedation. Use Caution/Monitor.

• pancuronium

  Monitor Closely (3)pancuronium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  pancuronium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of pancuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• papaveretum

  Monitor Closely (1)papaveretum and olanzapine both increase sedation. Use Caution/Monitor.

• papaverine

  Monitor Closely (1)olanzapine and papaverine both increase sedation. Use Caution/Monitor.

• paroxetine

  Monitor Closely (1)paroxetine, 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).

• pasireotide

  Monitor Closely (1)olanzapine and pasireotide both increase QTc interval. Modify Therapy/Monitor Closely.

• pefloxacin

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

• peginterferon alfa 2a

  Monitor Closely (1)peginterferon alfa 2a will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• pentazocine

  Monitor Closely (1)pentazocine and olanzapine both increase sedation. Use Caution/Monitor.

• pentobarbital

  Monitor Closely (2)pentobarbital will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  pentobarbital and olanzapine both increase sedation. Use Caution/Monitor.

• perphenazine

  Monitor Closely (2)olanzapine and perphenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and perphenazine both increase sedation. Use Caution/Monitor.

• phendimetrazine

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

• phenelzine

  Monitor Closely (1)phenelzine, 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).

• phenobarbital

  Monitor Closely (2)phenobarbital will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  phenobarbital and olanzapine both increase sedation. Use Caution/Monitor.

• phentermine

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

• phenylephrine

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

• phenylephrine PO

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

• pholcodine

  Monitor Closely (1)olanzapine and pholcodine both increase sedation. Use Caution/Monitor.

• pimozide

  Monitor Closely (2)olanzapine and pimozide both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and pimozide both increase sedation. Use Caution/Monitor.

• pioglitazone

  Monitor Closely (1)olanzapine, pioglitazone. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• pipemidic acid

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

• pirbuterol

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

• pitolisant

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

• pralidoxime

  Monitor Closely (3)pralidoxime decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  pralidoxime decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of pralidoxime by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• pramipexole

  Serious - Use Alternative (1)olanzapine decreases effects of pramipexole by pharmacodynamic antagonism. Contraindicated.

• pramlintide

  Monitor Closely (1)olanzapine, pramlintide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• primidone

  Monitor Closely (2)primidone will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  primidone and olanzapine both increase sedation. Use Caution/Monitor.

• procarbazine

  Monitor Closely (1)procarbazine, 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).

• prochlorperazine

  Monitor Closely (2)olanzapine and prochlorperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and prochlorperazine both increase sedation. Use Caution/Monitor.

• promethazine

  Monitor Closely (3)promethazine, 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 promethazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  promethazine and olanzapine both increase sedation. Use Caution/Monitor.

• propantheline

  Monitor Closely (3)propantheline decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  propantheline decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of propantheline by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• propofol

  Monitor Closely (1)propofol and olanzapine both increase sedation. Use Caution/Monitor.

• propylhexedrine

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

• protriptyline

  Monitor Closely (1)olanzapine and protriptyline both increase sedation. Use Caution/Monitor.

• quazepam

  Monitor Closely (1)quazepam and olanzapine both increase sedation. Use Caution/Monitor.

• quetiapine

  Monitor Closely (2)olanzapine and quetiapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and quetiapine both increase sedation. Use Caution/Monitor.

• quinine

  Monitor Closely (1)olanzapine and quinine both increase QTc interval. Use Caution/Monitor.

• ramelteon

  Monitor Closely (1)olanzapine and ramelteon both increase sedation. Use Caution/Monitor.

• rapacuronium

  Monitor Closely (3)rapacuronium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  rapacuronium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of rapacuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• remimazolam

  Monitor Closely (1)remimazolam, olanzapine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely. Coadministration may result in profound sedation, respiratory depression, coma, and/or death. Continuously monitor vital signs during sedation and recovery period if coadministered. Carefully titrate remimazolam dose if administered with opioid analgesics and/or sedative/hypnotics.

• repaglinide

  Monitor Closely (1)olanzapine, repaglinide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• ribociclib

  Serious - Use Alternative (1)ribociclib increases toxicity of olanzapine by QTc interval. Avoid or Use Alternate Drug. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances.

• rifampin

  Monitor Closely (1)rifampin will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• rimabotulinumtoxinB

  Monitor Closely (1)olanzapine, rimabotulinumtoxinB. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Anticholinergics may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.

• risperidone

  Monitor Closely (2)olanzapine and risperidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and risperidone both increase sedation. Use Caution/Monitor.

• ritonavir

  Monitor Closely (1)ritonavir decreases levels of olanzapine by increasing metabolism. Use Caution/Monitor.

• rocuronium

  Monitor Closely (3)rocuronium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  rocuronium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of rocuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• ropinirole

  Serious - Use Alternative (1)olanzapine decreases effects of ropinirole by pharmacodynamic antagonism. Contraindicated.

• rosiglitazone

  Monitor Closely (1)olanzapine, rosiglitazone. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• rucaparib

  Monitor Closely (1)rucaparib will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP1A2 substrates, if clinically indicated.

• ruxolitinib

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

• ruxolitinib topical

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

• safinamide

  Serious - Use Alternative (1)olanzapine decreases effects of safinamide by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Dopamine antagonists may decrease safinamide effects and exacerbate Parkinson disease symptoms.

• sage

  Minor (1)olanzapine and sage both increase sedation. Minor/Significance Unknown.

• salmeterol

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

• saxagliptin

  Monitor Closely (1)olanzapine, saxagliptin. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• scopolamine

  Monitor Closely (3)scopolamine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  scopolamine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of scopolamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• scullcap

  Monitor Closely (1)olanzapine and scullcap both increase sedation. Use Caution/Monitor.

• secobarbital

  Monitor Closely (2)secobarbital will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
  
  secobarbital and olanzapine both increase sedation. Use Caution/Monitor.

• selegiline

  Monitor Closely (1)selegiline, 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).

• selinexor

  Serious - Use Alternative (1)selinexor, olanzapine. unspecified interaction mechanism. Avoid or Use Alternate Drug. Patients treated with selinexor may experience neurological toxicities. Avoid taking selinexor with other medications that may cause dizziness or confusion.

• selpercatinib

  Monitor Closely (1)selpercatinib increases toxicity of olanzapine by QTc interval. Use Caution/Monitor.

• shepherd's purse

  Monitor Closely (1)olanzapine and shepherd's purse both increase sedation. Use Caution/Monitor.

• siponimod

  Serious - Use Alternative (1)olanzapine will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• sitagliptin

  Monitor Closely (1)olanzapine, sitagliptin. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• smoking

  Monitor Closely (1)smoking will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• sodium oxybate

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

• sodium sulfate/?magnesium sulfate/potassium chloride

  Monitor Closely (1)sodium sulfate/?magnesium sulfate/potassium chloride increases effects of olanzapine by unknown mechanism. Use Caution/Monitor. Closely monitor for evidence of enhanced CNS depression when using higher dose of magnesium sulfate together with a CNS depressant.

• sodium sulfate/potassium sulfate/magnesium sulfate

  Monitor Closely (1)sodium sulfate/potassium sulfate/magnesium sulfate increases effects of olanzapine by unknown mechanism. Use Caution/Monitor. Closely monitor for evidence of enhanced CNS depression when using higher dose of magnesium sulfate together with a CNS depressant.

• solifenacin

  Monitor Closely (3)solifenacin decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  solifenacin decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of solifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• sorafenib

  Monitor Closely (1)sorafenib and olanzapine both increase QTc interval. Use Caution/Monitor. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instances

• stiripentol

  Monitor Closely (2)stiripentol, olanzapine. Either increases effects of the other by sedation. Use Caution/Monitor. Concomitant use stiripentol with other CNS depressants, including alcohol, may increase the risk of sedation and somnolence.
  
  stiripentol, olanzapine. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP1A2 inhibitor and inducer. Monitor CYP1A2 substrates coadministered with stiripentol for increased or decreased effects. CYP1A2 substrates may require dosage adjustment.

• sufentanil

  Monitor Closely (1)sufentanil and olanzapine both increase sedation. Use Caution/Monitor.

• sufentanil SL

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

• sumatriptan

  Monitor Closely (1)sumatriptan, 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).

• sumatriptan intranasal

  Monitor Closely (1)sumatriptan intranasal, 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).

• tapentadol

  Monitor Closely (1)tapentadol and olanzapine both increase sedation. Use Caution/Monitor.

• tazemetostat

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

• temazepam

  Monitor Closely (1)temazepam and olanzapine both increase sedation. Use Caution/Monitor.

• terbutaline

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

• teriflunomide

  Monitor Closely (1)teriflunomide decreases levels of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• tetrabenazine

  Monitor Closely (1)olanzapine and tetrabenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Modify Therapy/Monitor Closely.

• thioridazine

  Monitor Closely (2)olanzapine and thioridazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and thioridazine both increase sedation. Use Caution/Monitor.

• thiothixene

  Monitor Closely (2)olanzapine and thiothixene both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and thiothixene both increase sedation. Use Caution/Monitor.

• tinidazole

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

• tiotropium

  Monitor Closely (3)tiotropium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  tiotropium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of tiotropium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• tobacco use

  Monitor Closely (1)tobacco use will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• tolazamide

  Monitor Closely (1)olanzapine, tolazamide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• tolbutamide

  Monitor Closely (1)olanzapine, tolbutamide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.

• tolterodine

  Monitor Closely (3)tolterodine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  tolterodine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of tolterodine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• topiramate

  Monitor Closely (1)olanzapine and topiramate both increase sedation. Modify Therapy/Monitor Closely.

• tramadol

  Monitor Closely (1)tramadol and olanzapine both increase sedation. Use Caution/Monitor.

• tranylcypromine

  Monitor Closely (1)tranylcypromine, 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).

• trazodone

  Monitor Closely (1)olanzapine and trazodone both increase sedation. Use Caution/Monitor.

• triazolam

  Monitor Closely (1)triazolam and olanzapine both increase sedation. Use Caution/Monitor.

• triclabendazole

  Monitor Closely (1)triclabendazole and olanzapine both increase QTc interval. Use Caution/Monitor.

• triclofos

  Monitor Closely (1)triclofos and olanzapine both increase sedation. Use Caution/Monitor.

• trifluoperazine

  Monitor Closely (2)olanzapine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and trifluoperazine both increase sedation. Use Caution/Monitor.

• trihexyphenidyl

  Monitor Closely (1)olanzapine increases effects of trihexyphenidyl by pharmacodynamic synergism. Use Caution/Monitor. Potential for additive anticholinergic effects.

• trimipramine

  Monitor Closely (1)olanzapine and trimipramine both increase sedation. Use Caution/Monitor.

• triprolidine

  Monitor Closely (1)triprolidine and olanzapine both increase sedation. Use Caution/Monitor.

• trospium chloride

  Monitor Closely (3)trospium chloride decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  trospium chloride decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of trospium chloride by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• umeclidinium bromide/vilanterol inhaled

  Serious - Use Alternative (1)olanzapine increases toxicity of umeclidinium bromide/vilanterol inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

• vecuronium

  Monitor Closely (3)vecuronium decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  vecuronium decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of vecuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• venlafaxine

  Monitor Closely (1)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).

• verapamil

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

• vilanterol/fluticasone furoate inhaled

  Serious - Use Alternative (1)olanzapine increases toxicity of vilanterol/fluticasone furoate inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

• vilazodone

  Monitor Closely (1)vilazodone, 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).

• voclosporin

  Monitor Closely (1)voclosporin, olanzapine. Either increases effects of the other by QTc interval. Use Caution/Monitor.

• xylometazoline

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

• yohimbine

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

• ziconotide

  Monitor Closely (1)olanzapine and ziconotide both increase sedation. Use Caution/Monitor.

• zileuton

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

• ziprasidone

  Monitor Closely (2)olanzapine and ziprasidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and ziprasidone both increase sedation. Use Caution/Monitor.

• zolmitriptan

  Monitor Closely (1)zolmitriptan, 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).

• zotepine

  Monitor Closely (2)olanzapine and zotepine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and zotepine both increase sedation. Use Caution/Monitor.