increase sedation. Use Caution/Monitor.ethosuximideMonitor Closely (1)brexpiprazole and ethosuximide both increase sedation. Use Caution/Monitor.ethotoinMonitor Closely (1)brexpiprazole and ethotoin both increase sedation. Use Caution/Monitor.etravirineMonitor Closely (1)etravirine will decrease the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Double brexpiprazole dose over 1-2 weeks if administered with a strong CYP3A4 inducer.fedratinibMonitor Closely (2)fedratinib will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary. fedratinib will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.felbamateMonitor Closely (1)brexpiprazole and felbamate both increase sedation. Use Caution/Monitor.fenfluramineMonitor Closely (1)brexpiprazole and fenfluramine both increase sedation. Use Caution/Monitor.fentanylSerious - Use Alternative (1)brexpiprazole and fentanyl both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequatefentanyl intranasalSerious - Use Alternative (1)brexpiprazole and fentanyl intranasal both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequatefentanyl iontophoretic transdermal systemSerious - Use Alternative (1)brexpiprazole and fentanyl iontophoretic transdermal system both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequatefentanyl transdermalSerious - Use Alternative (1)brexpiprazole and fentanyl transdermal both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequatefentanyl transmucosalSerious - Use Alternative (1)brexpiprazole and fentanyl transmucosal both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequatefexinidazoleSerious - Use Alternative (1)fexinidazole will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.fexofenadineMonitor Closely (1)brexpiprazole and fexofenadine both increase sedation. Use Caution/Monitor.flibanserinMonitor Closely (1)brexpiprazole and flibanserin both increase sedation. Use Caution/Monitor.fluconazoleMonitor Closely (1)fluconazole will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP3A4 inhibitor PLUS a strong/moderate CYP2D6 inhibitor.fluoxetineMonitor Closely (1)fluoxetine will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Administer half of the usual brexpiprazole dose when coadministered with strong CYP2D6 inhibitors. If also administered with a strong/moderate CYP3A4 inhibitor, administer a quarter of brexpiprazole dose. NOTE: In MDD clinical trials, brexpiprazole dosage was not adjusted for strong CYP2D6 inhibitors (eg, paroxetine, fluoxetine); thus, CYP considerations are already factored into general dosing recommendations and brexpiprazole may be administered without dosage adjustment in patients with MDD.fluphenazineMonitor Closely (1)brexpiprazole and fluphenazine both increase sedation. Use Caution/Monitor.flurazepamMonitor Closely (1)brexpiprazole and flurazepam both increase sedation. Use Caution/Monitor.fosamprenavirMonitor Closely (1)fosamprenavir will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer half of the usual brexpiprazole dose when coadministered with strong CYP3A4 inhibitors. If also administered with a strong/moderate CYP2D6 inhibitor, administer a quarter of brexpiprazole dose.fosaprepitantMonitor Closely (1)fosaprepitant will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP3A4 inhibitor PLUS a strong/moderate CYP2D6 inhibitor.fosphenytoinMonitor Closely (1)fosphenytoin will decrease the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Double brexpiprazole dose over 1-2 weeks if administered with a strong CYP3A4 inducer.gabapentinMonitor Closely (2)brexpiprazole and gabapentin both increase sedation. Use Caution/Monitor. gabapentin, brexpiprazole. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.gabapentin enacarbilMonitor Closely (1)gabapentin enacarbil, brexpiprazole. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.ganaxoloneMonitor Closely (1)brexpiprazole and ganaxolone both increase sedation. Use Caution/Monitor.givosiranSerious - Use Alternative (1)givosiran will increase the level or effect of brexpiprazole 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.grapefruitMonitor Closely (1)grapefruit will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer half of the usual brexpiprazole dose when coadministered with strong CYP3A4 inhibitors. If also administered with a strong/moderate CYP2D6 inhibitor, administer a quarter of brexpiprazole dose.guanfacineMonitor Closely (1)brexpiprazole and guanfacine both increase sedation. Use Caution/Monitor.haloperidolMonitor Closely (3)brexpiprazole and haloperidol both increase sedation. Use Caution/Monitor. haloperidol will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP2D6 inhibitor PLUS a strong/moderate CYP3A4 inhibitor. haloperidol will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP3A4 inhibitor PLUS a strong/moderate CYP2D6 inhibitor.hydrocodoneSerious - Use Alternative (1)brexpiprazole and hydrocodone both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequatehydromorphoneSerious - Use Alternative (1)brexpiprazole and hydromorphone both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequatehydroxyzineMonitor Closely (1)brexpiprazole and hydroxyzine both increase sedation. Use Caution/Monitor.idelalisibMonitor Closely (1)idelalisib will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer half of the usual brexpiprazole dose when coadministered with strong CYP3A4 inhibitors. If also administered with a strong/moderate CYP2D6 inhibitor, administer a quarter of brexpiprazole dose.iloperidoneMonitor Closely (2)iloperidone will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP3A4 inhibitor PLUS a strong/moderate CYP2D6 inhibitor. brexpiprazole and iloperidone both increase sedation. Use Caution/Monitor.imatinibMonitor Closely (2)imatinib will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer half of the usual brexpiprazole dose when coadministered with strong CYP3A4 inhibitors. If also administered with a strong/moderate CYP2D6 inhibitor, administer a quarter of brexpiprazole dose. imatinib will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP2D6 inhibitor PLUS a strong/moderate CYP3A4 inhibitor.imipramineMonitor Closely (2)brexpiprazole and imipramine both increase sedation. Use Caution/Monitor. imipramine will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP2D6 inhibitor PLUS a strong/moderate CYP3A4 inhibitor.indinavirMonitor Closely (1)indinavir will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer half of the usual brexpiprazole dose when coadministered with strong CYP3A4 inhibitors. If also administered with a strong/moderate CYP2D6 inhibitor, administer a quarter of brexpiprazole dose.isofluraneMonitor Closely (1)brexpiprazole and isoflurane both increase sedation. Use Caution/Monitor.isoniazidMonitor Closely (2)isoniazid will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer half of the usual brexpiprazole dose when coadministered with strong CYP3A4 inhibitors. If also administered with a strong/moderate CYP2D6 inhibitor, administer a quarter of brexpiprazole dose. isoniazid will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP2D6 inhibitor PLUS a strong/moderate CYP3A4 inhibitor.istradefyllineMonitor Closely (1)istradefylline will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.itraconazoleMonitor Closely (1)itraconazole will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer half of the usual brexpiprazole dose when coadministered with strong CYP3A4 inhibitors. If also administered with a strong/moderate CYP2D6 inhibitor, administer a quarter of brexpiprazole dose.ivosidenibSerious - Use Alternative (1)ivosidenib will decrease the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternate therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.ketamineMonitor Closely (1)brexpiprazole and ketamine both increase sedation. Use Caution/Monitor.ketoconazoleMonitor Closely (2)ketoconazole will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer half of the usual brexpiprazole dose when coadministered with strong CYP3A4 inhibitors. If also administered with a strong/moderate CYP2D6 inhibitor, administer a quarter of brexpiprazole dose. ketoconazole will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP2D6 inhibitor PLUS a strong/moderate CYP3A4 inhibitor.ketotifen, drug-eluting contact lensMonitor Closely (1)brexpiprazole and ketotifen, drug-eluting contact lens both increase sedation. Use Caution/Monitor.lamotrigineMonitor Closely (1)brexpiprazole and lamotrigine both increase sedation. Use Caution/Monitor.lapatinibMonitor Closely (1)lapatinib will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP3A4 inhibitor PLUS a strong/moderate CYP2D6 inhibitor.larotrectinibMinor (1)larotrectinib will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.lasmiditanMonitor Closely (1)lasmiditan, brexpiprazole. 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.lemborexantMonitor Closely (1)lemborexant, brexpiprazole. 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.lenacapavirMonitor Closely (1)lenacapavir will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lencapavir (a moderate CYP3A4 inhibitor) may increase CYP3A4 substrates initiated within 9 months after last SC dose of lenacapavir, which may increase potential risk of adverse reactions of CYP3A4 substrates. levetiracetamMonitor Closely (1)brexpiprazole and levetiracetam both increase sedation. Use Caution/Monitor.levocetirizineMonitor Closely (1)brexpiprazole and levocetirizine both increase sedation. Use Caution/Monitor.levoketoconazoleMonitor Closely (2)levoketoconazole will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP2D6 inhibitor PLUS a strong/moderate CYP3A4 inhibitor. levoketoconazole will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer half of the usual brexpiprazole dose when coadministered with strong CYP3A4 inhibitors. If also administered with a strong/moderate CYP2D6 inhibitor, administer a quarter of brexpiprazole dose.levorphanolMonitor Closely (1)brexpiprazole and levorphanol both increase sedation. Use Caution/Monitor.lidocaineMonitor Closely (2)lidocaine will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP2D6 inhibitor PLUS a strong/moderate CYP3A4 inhibitor. lidocaine will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP3A4 inhibitor PLUS a strong/moderate CYP2D6 inhibitor.lonafarnibSerious - Use Alternative (1)lonafarnib will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with sensitive CYP3A substrates. If coadministration unavoidable, monitor for adverse reactions and reduce CYP3A substrate dose in accordance with product labeling.lopinavirMonitor Closely (2)lopinavir will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Administer half of the usual brexpiprazole dose when coadministered with strong CYP2D6 inhibitors. If also administered with a strong/moderate CYP3A4 inhibitor, administer a quarter of brexpiprazole dose. NOTE: In MDD clinical trials, brexpiprazole dosage was not adjusted for strong CYP2D6 inhibitors (eg, paroxetine, fluoxetine); thus, CYP considerations are already factored into general dosing recommendations and brexpiprazole may be administered without dosage adjustment in patients with MDD. lopinavir will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer half of the usual brexpiprazole dose when coadministered with strong CYP3A4 inhibitors. If also administered