Contraindicated. Risk of QT interval prolongation.isoproterenolMonitor Closely (1)pimozide increases and isoproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.istradefyllineMonitor Closely (1)istradefylline will increase the level or effect of pimozide by affecting hepatic enzyme CYP2E1 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.itraconazoleContraindicated (1)itraconazole will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Both drugs will increase QT interval. Coadministration of pimozide and itraconazole is contraindicated during and 2 weeks after itraconazole treatment.ivosidenibSerious - Use Alternative (2)ivosidenib and pimozide 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 pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternative therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.ketoconazoleContraindicated (2)ketoconazole and pimozide both increase QTc interval. Contraindicated. ketoconazole increases levels of pimozide by decreasing metabolism. Contraindicated. Risk of QT interval prolongation.Monitor Closely (1)ketoconazole will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ketotifen, ophthalmicMonitor Closely (1)pimozide and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.lapatinibContraindicated (1)lapatinib increases levels of pimozide by decreasing metabolism. Contraindicated. Risk of QT interval prolongation.Serious - Use Alternative (1)lapatinib and pimozide both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)lapatinib will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.larotrectinibMinor (1)larotrectinib will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.lasmiditanMonitor Closely (1)lasmiditan, pimozide. 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.lefamulinContraindicated (1)lefamulin will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Lefamulin is contraindicated with CYP3A substrates know to prolong the QT interval.lemborexantMonitor Closely (2)pimozide will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Lower nightly dose of lemborexant recommended if coadministered with weak CYP3A4 inhibitors. See drug monograph for specific dosage modification. lemborexant, pimozide. 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.lenacapavirSerious - Use Alternative (1)lenacapavir will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.lenvatinibMonitor Closely (1)pimozide and lenvatinib both increase QTc interval. Use Caution/Monitor. Lenvatinib prescribing information recommends monitoring ECG closely when coadministered with QT prolonging drugs.letermovirContraindicated (1)letermovir increases levels of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of letermovir and pimozide is contraindicated due to risk of QT prolongations and torsades de pointes.leuprolideContraindicated (1)leuprolide increases toxicity of pimozide by QTc interval. Contraindicated. Increases risk of torsades de pointes.levalbuterolMonitor Closely (1)pimozide increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.levodopaSerious - Use Alternative (1)pimozide decreases effects of levodopa by pharmacodynamic antagonism. Avoid or Use Alternate Drug.levofloxacinSerious - Use Alternative (1)levofloxacin and pimozide both increase QTc interval. Avoid or Use Alternate Drug.levoketoconazoleContraindicated (2)levoketoconazole and pimozide both increase QTc interval. Contraindicated. levoketoconazole increases levels of pimozide by decreasing metabolism. Contraindicated. Risk of QT interval prolongation.Monitor Closely (1)levoketoconazole will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.levomilnacipranMonitor Closely (1)levomilnacipran, pimozide. 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).levorphanolMonitor Closely (1)levorphanol and pimozide both increase sedation. Use Caution/Monitor.lidocaineSerious - Use Alternative (1)lidocaine, pimozide. Mechanism: pharmacodynamic synergism. Contraindicated. Risk of prolonged QTc interval.linezolidMonitor Closely (1)linezolid, pimozide. 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).lisdexamfetamineMonitor Closely (1)pimozide increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.lisurideSerious - Use Alternative (1)pimozide decreases effects of lisuride by pharmacodynamic antagonism. Contraindicated.lithiumMonitor Closely (1)lithium, pimozide. 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)lithium and pimozide both increase QTc interval. Contraindicated.lofepramineContraindicated (1)lofepramine and pimozide both increase QTc interval. Contraindicated.Monitor Closely (1)pimozide and lofepramine both increase sedation. Use Caution/Monitor.lofexidineMonitor Closely (2)pimozide and lofexidine both increase QTc interval. Use Caution/Monitor. ECG monitoring is recommended. pimozide and lofexidine both increase sedation. Use Caution/Monitor.lomitapideMonitor Closely (1)pimozide increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lomitapide dose should not exceed 30 mg/day.lonafarnibSerious - Use Alternative (1)pimozide 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.lonapegsomatropinMonitor Closely (1)lonapegsomatropin will decrease the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Limited published data indicate that growth hormone treatment increases cytochrome P450 (CYP450)-mediated antipyrine clearance. Caution with sensitive CYP substrateslopinavirSerious - Use Alternative (1)lopinavir will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.loprazolamMonitor Closely (1)loprazolam and pimozide both increase sedation. Use Caution/Monitor.lorazepamMonitor Closely (1)lorazepam and pimozide both increase sedation. Use Caution/Monitor.lorcaserinMonitor Closely (1)lorcaserin, pimozide. 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).lorlatinibSerious - Use Alternative (1)lorlatinib will decrease the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid use of lorlatinib with CYP3A substrates, where minimal concentration changes may lead to serious therapeutic failures of the substrate. If concomitant use is unavoidable, increase CYP3A substrate dosage in accordance with approved product labeling.lormetazepamMonitor Closely (1)lormetazepam and pimozide both increase sedation. Use Caution/Monitor.loxapineMonitor Closely (2)loxapine and pimozide both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. loxapine and pimozide both increase sedation. Use Caution/Monitor.loxapine inhaledMonitor Closely (2)loxapine inhaled and pimozide both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. loxapine inhaled and pimozide both increase sedation. Use Caution/Monitor.lumacaftor/ivacaftorSerious - Use Alternative (1)lumacaftor/ivacaftor will decrease the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Lumacaftor is a strong inducer of CYP3A. Avoid coadministration with sensitive CYP3A substrates or CYP3A substrates with a narrow therapeutic index.lumefantrineContraindicated (1)lumefantrine and pimozide both increase QTc interval. Contraindicated.Minor (1)lumefantrine will decrease the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.lurasidoneMonitor Closely (1)lurasidone, pimozide. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Potential for increased CNS depressant effects when used concurrently; monitor for increased adverse effects and toxicity.macimorelinSerious - Use Alternative (1)macimorelin and pimozide 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.maprotilineContraindicated (1)maprotiline and pimozide both increase QTc interval. Contraindicated.Monitor Closely (1)pimozide and maprotiline both increase sedation. Use Caution/Monitor.marijuanaContraindicated (1)marijuana increases levels of pimozide by decreasing metabolism. Contraindicated. Risk of QT interval prolongation.Monitor Closely (1)pimozide and marijuana both increase sedation. Use Caution/Monitor.Minor (1)marijuana will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.mavacamtenMonitor Closely (1)pimozide will increase the level or effect of mavacamten by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Inititiation of weak CYP2C19 inhibitors may require decreased mavacamten dose. meclizineMonitor Closely (3)meclizine decreases levels of pimozide by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. meclizine decreases levels of pimozide by pharmacodynamic antagonism. Use Caution/Monitor. pimozide increases effects of meclizine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.mefloquineSerious - Use Alternative (1)mefloquine increases toxicity of pimozide by QTc interval. Avoid or Use Alternate Drug. Mefloquine may enhance the QTc prolonging effect of high risk QTc prolonging agents.melatoninMonitor Closely (1)pimozide and melatonin both increase sedation. Use Caution/Monitor.meperidineMonitor Closely (2)meperidine, pimozide. 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). meperidine and pimozide both increase sedation. Use Caution/Monitor.meprobamateMonitor Closely (1)pimozide and meprobamate both increase sedation. Use Caution/Monitor.metaproterenolMonitor Closely (1)pimozide increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.metaxaloneMonitor Closely (1)metaxalone and pimozide both increase sedation. Use Caution/Monitor.methadoneMonitor Closely (2)methadone, pimozide. 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). methadone and pimozide both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)methadone and pimozide both increase QTc interval. Avoid or Use Alternate Drug.methamphetamineMonitor Closely (1)pimozide increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.methocarbamolMonitor Closely (1)methocarbamol and pimozide both increase sedation. Use Caution/Monitor.methscopolamineMonitor Closely (3)methscopolamine decreases levels of pimozide by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. methscopolamine decreases levels of pimozide by pharmacodynamic antagonism. Use Caution/Monitor. pimozide increases effects of methscopolamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.methyldopaSerious - Use Alternative (1)pimozide decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.methylenedioxymethamphetamineMonitor Closely (1)pimozide increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.methylergonovineMonitor Closely (1)methylergonovine, pimozide. 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).methylphenidateMonitor Closely (1)pimozide increases toxicity of methylphenidate by pharmacodynamic antagonism. Use Caution/Monitor. Closely monitor for signs of altered clinical response to either methylphenidate or an antipsychotic when using these drugs in combination.methylprednisoloneMinor (1)methylprednisolone will decrease the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.metoclopramideMonitor Closely (1)pimozide and metoclopramide both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.metoclopramide intranasalSerious - Use Alternative (2)pimozide, metoclopramide intranasal. Either increases effects of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid use of metoclopramide intranasal or interacting drug, depending on importance of drug to patient. pimozide increases toxicity of metoclopramide