Avoid or Use Alternate Drug.dextromethorphanfluoxetine will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.fluoxetine and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug.disopyramidedisopyramide and fluoxetine both increase QTc interval. Avoid or Use Alternate Drug.dolasetrondolasetron, fluoxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.dopamineolanzapine decreases effects of dopamine by pharmacodynamic antagonism. Contraindicated.dosulepinfluoxetine and dosulepin both increase serotonin levels. Avoid or Use Alternate Drug.doxepinfluoxetine will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.fluoxetine and doxepin both increase serotonin levels. Avoid or Use Alternate Drug.droperidololanzapine and droperidol both increase QTc interval. Avoid or Use Alternate Drug.duloxetinefluoxetine will increase the level or effect of duloxetine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.duloxetine and fluoxetine both increase serotonin levels. Avoid or Use Alternate Drug.eliglustateliglustat and fluoxetine both increase QTc interval. Avoid or Use Alternate Drug.olanzapine and eliglustat both increase QTc interval. Avoid or Use Alternate Drug.encorafenibencorafenib and fluoxetine both increase QTc interval. Avoid or Use Alternate Drug. Encorafenib is associated with dose-dependent QTc interval prolongation. Avoid with drugs known to prolong QT interval.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 instancesentrectinibfluoxetine and entrectinib both increase QTc interval. Avoid or Use Alternate Drug.olanzapine and entrectinib both increase QTc interval. Avoid or Use Alternate Drug.erdafitinibolanzapine 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.escitalopramfluoxetine will increase the level or effect of escitalopram by affecting hepatic enzyme CYP2C19 metabolism. Avoid or Use Alternate Drug.escitalopram and fluoxetine both increase serotonin levels. Avoid or Use Alternate Drug.eribulineribulin 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 baseolanzapine and erythromycin base both increase QTc interval. Avoid or Use Alternate Drug.erythromycin ethylsuccinateolanzapine and erythromycin ethylsuccinate both increase QTc interval. Avoid or Use Alternate Drug.erythromycin lactobionateolanzapine and erythromycin lactobionate both increase QTc interval. Avoid or Use Alternate Drug.erythromycin stearateolanzapine and erythromycin stearate both increase QTc interval. Avoid or Use Alternate Drug.fedratinibolanzapine 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.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.fentanylfentanyl, fluoxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.fexinidazolefexinidazole 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.fentanyl intranasalfentanyl intranasal, fluoxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.fentanyl transdermalfentanyl transdermal, fluoxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.fentanyl transmucosalfentanyl transmucosal, fluoxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.fexinidazolefexinidazole 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.flecainidefluoxetine will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.fluphenazinefluoxetine will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.fluphenazine and fluoxetine both increase QTc interval. Avoid or Use Alternate Drug.fluvoxaminefluvoxamine and fluoxetine both increase serotonin levels. Avoid or Use Alternate Drug.olanzapine and fluvoxamine both increase QTc interval. Avoid or Use Alternate Drug.fluvoxamine will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug.foscarnetolanzapine and foscarnet both increase QTc interval. Avoid or Use Alternate Drug.gilteritinibgilteritinib will decrease the level or effect of fluoxetine by Other (see comment). Avoid or Use Alternate Drug. Coadministration of gilteritinib with drugs that inhibit 5HT2B or sigma nonspecific receptors. Avoid use of these drugs with gilteritinib unless coadministration is necessary.gilteritinib and fluoxetine both increase QTc interval. Avoid or Use Alternate Drug.givosirangivosiran 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.givosiran will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP2D6 substrates with givosiran. If unavoidable, decrease the CYP2D6 substrate dosage in accordance with approved product labeling.glasdegibolanzapine and glasdegib both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, monitor for increased risk of QTc interval prolongation.fluoxetine and glasdegib both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, monitor for increased risk of QTc interval prolongation.goserelinolanzapine and goserelin both increase QTc interval. Avoid or Use Alternate Drug.granisetrongranisetron, fluoxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.haloperidolfluoxetine will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.haloperidol will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.histrelinolanzapine and histrelin both increase QTc interval. Avoid or Use Alternate Drug.histrelin increases toxicity of fluoxetine by QTc interval. Avoid or Use Alternate Drug. Increases risk of torsades de pointes.hydrocodonehydrocodone, 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.hydromorphonefluoxetine will increase the level or effect of hydromorphone by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.hydromorphone, fluoxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.hydroxychloroquine sulfatehydroxychloroquine sulfate and fluoxetine both increase QTc interval. Avoid or Use Alternate Drug.hydroxychloroquine sulfate and olanzapine both increase QTc interval. Avoid or Use Alternate Drug.hydroxyzinehydroxyzine increases toxicity of fluoxetine by QTc interval. Avoid or Use Alternate Drug. Increases risk of torsades de pointes.ibutilideolanzapine and ibutilide both increase QTc interval. Avoid or Use Alternate Drug.ibutilidefluoxetine and ibutilide both increase QTc interval. Avoid or Use Alternate Drug.iloperidonefluoxetine will increase the level or effect of iloperidone by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.olanzapine and iloperidone both increase QTc interval. Avoid or Use Alternate Drug.imipraminefluoxetine will increase the level or effect of imipramine by affecting hepatic enzyme CYP2C19 metabolism. Avoid or Use Alternate Drug.fluoxetine will increase the level or effect of imipramine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.fluoxetine and imipramine both increase serotonin levels. Avoid or Use Alternate Drug.inotuzumabolanzapine and inotuzumab both increase QTc interval. Avoid or Use Alternate Drug.indapamidefluoxetine and indapamide both increase QTc interval. Avoid or Use Alternate Drug.isofluraneisoflurane and fluoxetine both increase QTc interval. Avoid or Use Alternate Drug.isoflurane 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 instancesivosidenibivosidenib and fluoxetine 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.ivosidenib will decrease the level or effect of fluoxetine by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP2C9 substrates with ivosidenib or replace with alternate therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.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.lefamulinlefamulin and olanzapine both increase QTc interval. Avoid or Use Alternate Drug.lefamulin and fluoxetine both increase QTc interval. Avoid or Use Alternate Drug.leniolisibleniolisib will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. Avoid leniolisib with CYP1A2 substrates that have a narrow therapeutic indexlevomilnacipranfluoxetine and levomilnacipran both increase serotonin levels. Avoid or Use Alternate Drug.lenvatinibolanzapine and lenvatinib both increase QTc interval. Avoid or Use Alternate Drug.leuprolideolanzapine and leuprolide both increase QTc interval. Avoid or Use Alternate Drug.levodopaolanzapine decreases effects of levodopa by pharmacodynamic antagonism. Avoid or Use Alternate Drug.levodopa inhaledolanzapine 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). .lisurideolanzapine decreases effects of lisuride by pharmacodynamic antagonism. Contraindicated.lofepraminefluoxetine will increase the level or effect of lofepramine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.fluoxetine and lofepramine both increase serotonin levels. Avoid or Use Alternate Drug.lonafarnibfluoxetine 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.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.lopinavirolanzapine and lopinavir both increase QTc interval. Avoid or Use Alternate Drug.lorcaserinfluoxetine and lorcaserin both increase serotonin levels. Avoid or Use Alternate Drug.macimorelinmacimorelin and fluoxetine 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.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.maprotilineolanzapine and maprotiline both increase QTc interval. Avoid or Use Alternate Drug.fluoxetine and maprotiline both increase serotonin levels. Avoid or Use Alternate Drug.mefloquinemefloquine 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.mefloquine increases toxicity of fluoxetine by QTc interval. Avoid or Use Alternate Drug. Mefloquine may enhance the QTc prolonging effect of high risk QTc prolonging agents.meperidinefluoxetine and meperidine both increase serotonin levels. Avoid or Use Alternate Drug.meperidine, fluoxetine. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug.methadoneolanzapine and methadone both increase QTc interval. Avoid or Use Alternate Drug.methamphetaminefluoxetine will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.methyldopaolanzapine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.methylenedioxymethamphetaminefluoxetine increases toxicity of methylenedioxymethamphetamine by decreasing elimination. Contraindicated.metoclopramidemetoclopramide and fluoxetine both increase serotonin levels. Avoid or Use Alternate Drug. Additive effects; increased risk for serotonin syndrome, neuroleptic malignant syndrome, dystonia, or other extrapyramidal reactionsmetoclopramide intranasalolanzapine increases toxicity of metoclopramide intranasal by pharmacodynamic synergism. Avoid or Use