some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval in rare instancesentrectinibSerious - Use Alternative (2)fluoxetine and entrectinib both increase QTc interval. Avoid or Use Alternate Drug. olanzapine and entrectinib both increase QTc interval. Avoid or Use Alternate Drug.epcoritamabMonitor Closely (1)epcoritamab, olanzapine. affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. Epcoritamab causes release of cytokines that may suppress activity of CYP enzymes, resulting in increased exposure of CYP substrates. For certain CYP substrates, minimal changes in their concentration may lead to serious adverse reactions. If needed, modify therapy as recommended in the substrate's prescribing information. .ephedrineMonitor Closely (1)olanzapine increases and ephedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.epinephrineMonitor Closely (2)olanzapine increases and epinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. epinephrine and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.epinephrine racemicMonitor Closely (2)olanzapine increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. epinephrine racemic and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.erdafitinibSerious - 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 mesylatesMonitor 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).ergotamineMonitor Closely (2)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). fluoxetine and ergotamine both increase serotonin levels. Modify Therapy/Monitor Closely.eribulinMonitor Closely (1)eribulin and fluoxetine both increase QTc interval. Use Caution/Monitor.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 instanceserythromycin baseMonitor Closely (2)erythromycin base and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely. erythromycin base will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)olanzapine and erythromycin base both increase QTc interval. Avoid or Use Alternate Drug.erythromycin ethylsuccinateMonitor Closely (2)erythromycin ethylsuccinate and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely. erythromycin ethylsuccinate will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)olanzapine and erythromycin ethylsuccinate both increase QTc interval. Avoid or Use Alternate Drug.erythromycin lactobionateMonitor Closely (2)erythromycin lactobionate and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely. erythromycin lactobionate will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)olanzapine and erythromycin lactobionate both increase QTc interval. Avoid or Use Alternate Drug.erythromycin stearateMonitor Closely (2)erythromycin stearate will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. erythromycin stearate and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)olanzapine and erythromycin stearate both increase QTc interval. Avoid or Use Alternate Drug.escitalopramMonitor Closely (2)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. escitalopram and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (2)escitalopram and fluoxetine both increase serotonin levels. Avoid or Use Alternate Drug. fluoxetine will increase the level or effect of escitalopram by affecting hepatic enzyme CYP2C19 metabolism. Avoid or Use Alternate Drug.esketamine intranasalMonitor Closely (1)esketamine intranasal, olanzapine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.esomeprazoleMinor (1)fluoxetine will increase the level or effect of esomeprazole by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.estazolamMonitor Closely (1)estazolam and olanzapine both increase sedation. Use Caution/Monitor.ethacrynic acidMinor (1)ethacrynic acid, fluoxetine. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Possible additive hyponatremia.ethanolMonitor 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.ethinylestradiolMonitor Closely (1)ethinylestradiol will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.ethotoinMonitor Closely (1)fluoxetine will increase the level or effect of ethotoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.etodolacMonitor Closely (1)fluoxetine, etodolac. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.etravirineMonitor Closely (1)fluoxetine will increase the level or effect of etravirine by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.eucalyptusMinor (1)olanzapine and eucalyptus both increase sedation. Minor/Significance Unknown.exenatide injectable solutionMonitor 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 suspensionMonitor 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.ezogabineMonitor Closely (1)ezogabine and fluoxetine both increase QTc interval. Use Caution/Monitor. Slight and transient QT-prolongation observed with ezogabine, particularly when dose titrated to 1200 mg/day. QT interval should be monitored when ezogabine is prescribed with agents known to increase QT interval.fedratinibMonitor Closely (1)fedratinib will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.Serious - Use Alternative (2)fluoxetine 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. 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.fenbufenMonitor Closely (1)fluoxetine, fenbufen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.fenfluramineMonitor Closely (4)olanzapine decreases effects of fenfluramine by pharmacodynamic antagonism. Use Caution/Monitor. Potent serotonin receptor antagonists may decrease fenfluramine efficacy. If coadministered, monitor appropriately. fenfluramine, fluoxetine. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Coadministration with drugs that increase serotoninergic effects may increase the risk of serotonin syndrome. olanzapine increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. fluoxetine and fenfluramine both increase serotonin levels. Modify Therapy/Monitor Closely.fenoprofenMonitor Closely (1)fluoxetine, fenoprofen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.fentanylMonitor 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).Serious - Use Alternative (1)fentanyl, fluoxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.fentanyl intranasalSerious - Use Alternative (1)fentanyl intranasal, fluoxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.fentanyl transdermalSerious - Use Alternative (1)fentanyl transdermal, fluoxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.fentanyl transmucosalSerious - Use Alternative (1)fentanyl transmucosal, fluoxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.fesoterodineMonitor Closely (4)fesoterodine decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor. fesoterodine decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. fluoxetine will increase the level or effect of fesoterodine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. olanzapine increases effects of fesoterodine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.fexinidazoleMonitor Closely (1)fexinidazole will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.Serious - Use Alternative (2)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. fexinidazole and fluoxetine both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to block potassium channels or prolong QT interval.fezolinetantContraindicated (2)fluoxetine will increase the level or effect of fezolinetant by affecting hepatic enzyme CYP1A2 metabolism. Contraindicated. Fezolinetant AUC and peak plasma concentration are increased if coadministered with drugs that are weak, moderate, or strong CYP1A2 inhibitors olanzapine will increase the level or effect of fezolinetant by affecting hepatic enzyme CYP1A2 metabolism. Contraindicated. Fezolinetant AUC and peak plasma concentration are increased if coadministered with drugs that are weak, moderate, or strong CYP1A2 inhibitorsfinerenoneMonitor Closely (2)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. fluoxetine 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.fingolimodMonitor Closely (2)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 fingolimod and fluoxetine both increase QTc interval. Use Caution/Monitor.fish oil triglyceridesMonitor Closely (1)fish oil triglycerides will increase the level or effect of fluoxetine by anticoagulation. Use Caution/Monitor. Prolonged bleeding reported in patients taking antiplatelet agents or anticoagulants and oral omega-3 fatty acids. Periodically monitor bleeding time in patients receiving fish oil triglycerides and concomitant antiplatelet agents or anticoagulants.flavoxateMonitor 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.flecainideMonitor Closely (2)olanzapine and flecainide both increase QTc interval. Use Caution/Monitor. flecainide and fluoxetine both increase QTc interval. Use Caution/Monitor.Serious - Use Alternative (1)fluoxetine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.flibanserinMonitor Closely (3)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). 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. fluoxetine 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.fluconazoleMonitor Closely (2)olanzapine and fluconazole both increase QTc interval. Use Caution/Monitor. fluconazole and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.fluoxetineMonitor Closely (1)olanzapine and fluoxetine both increase QTc interval. Use Caution/Monitor.fluphenazineMonitor Closely (3)olanzapine and fluphenazine both increase QTc interval. Use Caution/Monitor. 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.Serious - Use Alternative (2)fluphenazine and fluoxetine both increase QTc interval. Avoid or Use Alternate Drug. fluoxetine will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.flurazepamMonitor Closely (1)flurazepam and olanzapine both increase sedation. Use Caution/Monitor.flurbiprofenMonitor Closely