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.fluoxetine, buprenorphine, long-acting injection. Either increases toxicity of the other by serotonin levels. Use Caution/Monitor. Concomitant use could result in life-threatening serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation, and during dose adjustment of the serotonergic drug. Discontinue buprenorphine if serotonin syndrome is suspected.buprenorphine, long-acting injection and olanzapine both increase sedation. Use Caution/Monitor.bupropionbupropion will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.butabarbitalbutabarbital 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.butalbitalbutalbital 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.butorphanolbutorphanol and olanzapine both increase sedation. Use Caution/Monitor.caffeineolanzapine increases and caffeine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.cannabidiolfluoxetine will increase the level or effect of cannabidiol by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Consider reducing the cannabidiol dose when coadministered with a moderate CYP2C19 inhibitor.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.cannabidiol will increase the level or effect of fluoxetine by decreasing metabolism. Modify Therapy/Monitor Closely. Cannabidiol may potentially inhibit CYP2C9 activity. Consider reducing the dose when concomitantly using CYP2C9 substrates.captoprilolanzapine, captopril. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Both drugs lower blood pressure. Monitor blood pressure.carbamazepinefluoxetine will increase the level or effect of carbamazepine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor plasma levels when used concomitantlycarbamazepinecarbamazepine will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.carbinoxaminecarbinoxamine and olanzapine both increase sedation. Use Caution/Monitor.carisoprodolcarisoprodol and olanzapine both increase sedation. Use Caution/Monitor.carvedilolfluoxetine will increase the level or effect of carvedilol by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.celecoxibfluoxetine will increase the level or effect of celecoxib by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.celecoxib will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.fluoxetine, celecoxib. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.chloral hydratechloral hydrate and olanzapine both increase sedation. Use Caution/Monitor.chlordiazepoxidechlordiazepoxide and olanzapine both increase sedation. Use Caution/Monitor.chloroquinechloroquine increases toxicity of olanzapine by QTc interval. Use Caution/Monitor.chlorpheniraminechlorpheniramine and olanzapine both increase sedation. Use Caution/Monitor.chlorpromazinechlorpromazine and olanzapine both increase sedation. Use Caution/Monitor.chlorpromazine and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.chlorpromazine and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.chlorpropamidefluoxetine increases effects of chlorpropamide by unspecified interaction mechanism. Use Caution/Monitor. Risk of hypoglycemia.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.chlorzoxazonechlorzoxazone and olanzapine both increase sedation. Use Caution/Monitor.choline magnesium trisalicylatefluoxetine, choline magnesium trisalicylate. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.cigarette smokingcigarette smoking will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.cilostazolfluoxetine increases toxicity of cilostazol by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Consider decreasing cilostazol dose; moderate CYP2C19 inhibitors may increase serum levels of 3,4-dehydrocilostazol (active metabolite).cimetidinecimetidine will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.cimetidine will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.cinnarizinecinnarizine and olanzapine both increase sedation. Use Caution/Monitor.ciprofloxacinciprofloxacin and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.ciprofloxacinciprofloxacin 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.cisatracuriumcisatracurium 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.citalopramcitalopram and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.clarithromycinclarithromycin and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.clemastineclemastine and olanzapine both increase sedation. Use Caution/Monitor.clobazamolanzapine, clobazam. Other (see comment). Use Caution/Monitor. Comment: Concomitant administration can increase the potential for CNS effects (e.g., increased sedation or respiratory depression).clobazam will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Lower doses of drugs metabolized by CYP2D6 may be required when used concomitantly. clomipramineolanzapine and clomipramine both increase sedation. Use Caution/Monitor.clomipramine and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.olanzapine and clomipramine both increase QTc interval. Use Caution/Monitor.clonazepamclonazepam and olanzapine both increase sedation. Use Caution/Monitor.clonidineclonidine, fluoxetine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration enhances CNS depressant effects.clonidineclonidine, olanzapine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects; potential delirium.clopidogrelfluoxetine increases effects of clopidogrel by pharmacodynamic synergism. Use Caution/Monitor. SSRIs affect platelet activation; coadministration of SSRIs with clopidogrel may increase the risk of bleeding.clorazepateclorazepate and olanzapine both increase sedation. Use Caution/Monitor.clozapinefluoxetine increases levels of clozapine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Plasma levels of clozapine may be increased, resulting in increased pharmacologic and toxic effects. Adjust clozapine dose as needed when initiating or discontinuing certain SSRIs. .clozapine and olanzapine both increase sedation. Use Caution/Monitor.clozapine and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.clozapine and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.cobicistatcobicistat will increase the level or effect of fluoxetine by Other (see comment). Use Caution/Monitor. Carefully titrate dose of the antidepressant to the desired effect, including using the lowest feasible initial or maintenance dose, and monitor its response during coadministration with SSRIs and cobicistat. codeinecodeine and olanzapine both increase sedation. Use Caution/Monitor.cocaine topicalfluoxetine and cocaine topical both increase serotonin levels. Modify Therapy/Monitor Closely.codeinefluoxetine will decrease the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphinecrizotinibcrizotinib and fluoxetine both increase QTc interval. Use Caution/Monitor. ECG monitoring is recommended, along with drugs that may prolong the QT interval.cyclizinecyclizine 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.cyclobenzaprinecyclobenzaprine 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.cyproheptadinecyproheptadine decreases effects of fluoxetine by pharmacodynamic antagonism. Use Caution/Monitor. Cyproheptadine may diminish the serotonergic effect of SSRIs.cyproheptadine and olanzapine both increase sedation. Use Caution/Monitor.dantrolenedantrolene and olanzapine both increase sedation. Use Caution/Monitor.daridorexantfluoxetine 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. daridorexantolanzapine 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. darifenacindarifenacin 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.darunavirdarunavir will increase the level or effect of fluoxetine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration with SSRIs, TCAs, or trazodone may require dose titration of antidepressant to desired effect (eg, using the lowest feasible initial or maintenance dose). Monitor for antidepressant response.dasatinibdasatinib 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 instancesdasatinib and fluoxetine both increase QTc interval. Use Caution/Monitor.deferasiroxdeferasirox will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.defibrotidedefibrotide increases effects of fluoxetine by Other (see comment). Use Caution/Monitor. Comment: Defibrotide may enhance effects of platelet inhibitors.degarelixdegarelix and fluoxetine both increase QTc interval. Use Caution/Monitor.desipramineolanzapine and desipramine both increase sedation. Use Caution/Monitor.olanzapine and desipramine both increase QTc interval. Use Caution/Monitor.desipramine and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.desvenlafaxinedesvenlafaxine will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Desvenlafaxine inhibits CYP2D6; with higher desvenlafaxine doses (ie, 400 mg) decrease the CYP2D6 substrate dose by up to 50%; no dosage adjustment needed with desvenlafaxine doses <100 mgdeutetrabenazineolanzapine 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. At the maximum recommended dose, deutetrabenazine does not prolong QT interval to a clinically relevant extent. Certain circumstances may increase risk of torsade de pointes and/or sudden death in association with drugs that prolong the QTc interval (eg, bradycardia, hypokalemia or hypomagnesemia, coadministration with other drugs that prolong QTc interval, presence of congenital QT prolongation).deutetrabenazinefluoxetine will increase the level or effect of deutetrabenazine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Strong CYP2D6 inhibitors increase the systemic exposure to the active dihydro-metabolites of deutetrabenazine by approximately 3-fold. Do not exceed 18 mg/dose and 36 mg/day of deutetrabenazine if coadministered with strong CYP2D6 inhibitors.deutetrabenazine and fluoxetine both increase QTc interval. Use Caution/Monitor. At the maximum recommended dose, deutetrabenazine does not prolong QT interval to a clinically relevant extent. Certain circumstances may increase risk of torsade de pointes and/or sudden death in association with drugs that prolong the QTc interval (eg, bradycardia, hypokalemia or hypomagnesemia, coadministration with other drugs that prolong QTc interval, presence of congenital QT prolongation).dexchlorpheniraminedexchlorpheniramine and olanzapine both increase sedation. Use Caution/Monitor.dexfenfluraminefluoxetine will increase the level or effect of dexfenfluramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.fluoxetine and dexfenfluramine both increase serotonin levels. Modify Therapy/Monitor Closely.olanzapine increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.dexmedetomidinedexmedetomidine and olanzapine both increase sedation. Use Caution/Monitor.dextroamphetaminefluoxetine will increase the level or effect of dextroamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.fluoxetine and dextroamphetamine both increase serotonin levels. Modify Therapy/Monitor Closely.dexmethylphenidateolanzapine increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.dextroamphetamineolanzapine increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.dextroamphetamine transdermalfluoxetine, dextroamphetamine transdermal. Either increases effects of the other by serotonin levels. Modify Therapy/Monitor Closely. Initiate with lower doses and monitor for signs and symptoms of serotonin syndrome, particularly during initiation or dosage increase. If serotonin syndrome occurs, discontinue dextroamphetamine transdermal and concomitant serotonergic drug(s).fluoxetine will increase the level or effect of dextroamphetamine transdermal by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Initiate with lower doses and monitor patients for signs and symptoms of serotonin syndrome, particularly during dextroamphetamine initiation and after a dosage increase. If serotonin syndrome occurs, discontinue dextroamphetamine transdermal and CYP2D6 inhibitor.dextromethorphandextromethorphan, 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).dextromoramidedextromoramide and olanzapine both increase sedation. Use Caution/Monitor.diamorphinediamorphine and olanzapine both increase sedation. Use Caution/Monitor.diazepamfluoxetine will increase the level or effect of diazepam by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.diazepam and olanzapine both increase sedation. Use Caution/Monitor.diazepam intranasalfluoxetine will increase the level or effect of diazepam intranasal by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Strong or moderate