effects of solifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.solifenacin and fluoxetine both increase QTc interval. Use Caution/Monitor.solifenacin decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.olanzapine and solifenacin both increase QTc interval. Use Caution/Monitor.somapacitansomapacitan will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. Limited published data indicate that growth hormone treatment increases cytochrome P450 (CYP450)-mediated antipyrine clearance. Caution with sensitive CYP substratessorafenibsorafenib and fluoxetine both increase QTc interval. Use Caution/Monitor.somatrogonsomatrogon will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. Limited published data indicate that growth hormone treatment increases cytochrome P450 (CYP450)-mediated antipyrine clearance. Caution with sensitive CYP substratessomatropinsomatropin will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. Limited published data indicate that growth hormone treatment increases cytochrome P450 (CYP450)-mediated antipyrine clearance. Caution with sensitive CYP substratessorafenibsorafenib 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 instancessparsentansparsentan will decrease the level or effect of fluoxetine by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. Sparsentan (a CYP2C9 inducer) decreases exposure of CYP2C9 substrates and reduces efficacy related to these substrates. stiripentolstiripentol, 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.sufentanilsufentanil and olanzapine both increase sedation. Use Caution/Monitor.sufentanil SLsufentanil SL, fluoxetine. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Coadministration of drugs that affect the serotonergic neurotransmitter system may result in serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment.sulfamethoxazolefluoxetine will increase the level or effect of sulfamethoxazole by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.sulfasalazinefluoxetine, sulfasalazine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.sulindacfluoxetine, sulindac. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.sumatriptansumatriptan, 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 and fluoxetine both increase serotonin levels. Modify Therapy/Monitor Closely.sumatriptan intranasalsumatriptan 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).sumatriptan intranasal and fluoxetine both increase serotonin levels. Modify Therapy/Monitor Closely.sunitinibolanzapine and sunitinib both increase QTc interval. Use Caution/Monitor.sunitinib and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.tacrolimustacrolimus and fluoxetine both increase QTc interval. Use Caution/Monitor.olanzapine and tacrolimus both increase QTc interval. Use Caution/Monitor.tamoxifenfluoxetine will decrease the level or effect of tamoxifen by decreasing metabolism. Use Caution/Monitor. Inhibition of CYP2D6 metabolism to tamoxifen's active metabolite, endoxifen.tapentadoltapentadol and olanzapine both increase sedation. Use Caution/Monitor.tamsulosinfluoxetine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.tapentadolfluoxetine and tapentadol both increase serotonin levels. Modify Therapy/Monitor Closely.tazemetostatolanzapine will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.fluoxetine will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.telavancinfluoxetine and telavancin both increase QTc interval. Use Caution/Monitor.olanzapine and telavancin both increase QTc interval. Use Caution/Monitor.temazepamtemazepam and olanzapine both increase sedation. Use Caution/Monitor.terbinafineterbinafine will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Assess need to reduce dose of CYP2D6-metabolized drug.terbutalinefluoxetine and terbutaline both increase QTc interval. Modify Therapy/Monitor Closely. Fluoxetine prolongs the QT interval; the prescribing information for fluoxetine recommends avoiding concurrent use of other drugs that may prolong the QT interval; risk may be increased with higher doses and/or when associated with hypokalemia; drugs that prolong the QTc interval may potentiate the effects of beta2 agonists on the cardiovascular systemolanzapine increases and terbutaline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.teriflunomideteriflunomide decreases levels of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.tetrabenazinefluoxetine increases effects of tetrabenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Decrease tetrabenazine dose by 50% when coadministered with strong CYP2D6 inhibitors.tetrabenazineolanzapine and tetrabenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Modify Therapy/Monitor Closely.thioridazineolanzapine 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.thiothixeneolanzapine and thiothixene both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.thiothixene and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.olanzapine and thiothixene both increase sedation. Use Caution/Monitor.tinidazolefluoxetine will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.olanzapine will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.tiotropiumtiotropium 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.tolazamidefluoxetine increases effects of tolazamide by unspecified interaction mechanism. Use Caution/Monitor. Risk of hypoglycemia.tobacco usetobacco use will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.tolazamideolanzapine, 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.tolbutamidefluoxetine increases effects of tolbutamide by unspecified interaction mechanism. Use Caution/Monitor. Risk of hypoglycemia.fluoxetine will increase the level or effect of tolbutamide by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.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.tolfenamic acidfluoxetine, tolfenamic acid. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.tolterodinetolterodine 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.tolmetinfluoxetine, tolmetin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.topiramateolanzapine and topiramate both increase sedation. Modify Therapy/Monitor Closely.toremifenetoremifene and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.tramadoltramadol and olanzapine both increase sedation. Use Caution/Monitor.fluoxetine and tramadol both increase serotonin levels. Modify Therapy/Monitor Closely.tranylcyprominetranylcypromine, 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).trazodonetrazodone and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.trazodoneolanzapine and trazodone both increase sedation. Use Caution/Monitor.triazolamtriazolam and olanzapine both increase sedation. Use Caution/Monitor.triclabendazoletriclabendazole and olanzapine both increase QTc interval. Use Caution/Monitor.triclabendazole and fluoxetine both increase QTc interval. Use Caution/Monitor.triclofostriclofos and olanzapine both increase sedation. Use Caution/Monitor.trifluoperazinefluoxetine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.trifluoperazine and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.trifluoperazineolanzapine 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.olanzapine and trifluoperazine both decrease QTc interval. Use Caution/Monitor.trihexyphenidylolanzapine increases effects of trihexyphenidyl by pharmacodynamic synergism. Use Caution/Monitor. Potential for additive anticholinergic effects.trimethoprimfluoxetine and trimethoprim both increase QTc interval. Use Caution/Monitor.trimipramineolanzapine and trimipramine both increase QTc interval. Use Caution/Monitor.trimipramine and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.olanzapine and trimipramine both increase sedation. Use Caution/Monitor.triprolidinetriprolidine and olanzapine both increase sedation. Use Caution/Monitor.tropisetronfluoxetine will increase the level or effect of tropisetron by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.fluoxetine and tropisetron both increase QTc interval. Use Caution/Monitor.trospium chloridetrospium 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 inhaledfluoxetine and umeclidinium bromide/vilanterol inhaled both increase QTc interval. Modify Therapy/Monitor Closely. Fluoxetine prolongs the QT interval; the prescribing information for fluoxetine recommends avoiding concurrent use of other drugs that may prolong the QT interval; risk may be increased with higher doses and/or when associated with hypokalemia; drugs that prolong the QTc interval may potentiate the effects of beta2 agonists on the cardiovascular systemvalbenazinevalbenazine and olanzapine both increase QTc interval. Use Caution/Monitor.fluoxetine will increase the level or effect of valbenazine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Consider reducing valbenazine dose based on tolerability if coadministered with a strong CYP2D6 inhibitor.valbenazine and fluoxetine both increase QTc interval. Use Caution/Monitor.valerianvalerian and fluoxetine both increase sedation. Use Caution/Monitor.vardenafilolanzapine and vardenafil both increase QTc interval. Use Caution/Monitor.vardenafilvardenafil and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.vecuroniumvecuronium 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.venlafaxinefluoxetine and venlafaxine both increase QTc interval. Use Caution/Monitor.olanzapine and venlafaxine both decrease QTc interval. Use Caution/Monitor.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).verapamilverapamil will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.vilanterol/fluticasone furoate inhaledfluoxetine and vilanterol/fluticasone furoate inhaled both increase QTc interval. Modify Therapy/Monitor Closely. Fluoxetine prolongs the QT interval; the prescribing information for fluoxetine recommends avoiding concurrent use of other drugs that may prolong the QT interval; risk may be increased with higher doses and/or when associated with hypokalemia; drugs that prolong the QTc interval may potentiate the effects of beta2 agonists on the cardiovascular systemvilazodonevilazodone, 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).voclosporinvoclosporin, olanzapine. Either increases effects of the other by QTc interval. Use Caution/Monitor.voclosporin, fluoxetine. Either increases effects of the other by QTc interval. Use Caution/Monitor.vorapaxarfluoxetine, vorapaxar. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive antiplatelet effect may occur; SSRIs and SNRIs may cause platelet serotonin depletion .voriconazoleolanzapine and voriconazole both increase QTc interval. Use Caution/Monitor.voriconazolefluoxetine will increase the level or effect of voriconazole by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.fluoxetine and voriconazole both increase QTc interval. Use Caution/Monitor.vorinostatolanzapine and vorinostat both increase QTc interval. Use Caution/Monitor.vorinostat and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.warfarinfluoxetine, warfarin. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Serotonin release by platelets plays an important role in hemostasis. SSRIs and SNRIs may increase anticoagulation effect of warfarin. .xylometazolineolanzapine increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.yohimbineolanzapine increases and yohimbine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.zanubrutinibfluoxetine, zanubrutinib. Either increases effects of the other by anticoagulation. Modify Therapy/Monitor Closely. Zanubrutinib-induced cytopenias increases risk of hemorrhage. Coadministration of zanubritinib with antiplatelets or anticoagulants may further increase this risk.ziconotideolanzapine and