Coadministration of beta-blockers and haloperidol may cause an unexpected severe hypotensive reaction. propylhexedrineMonitor Closely (1)haloperidol increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.protriptylineMonitor Closely (1)haloperidol and protriptyline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)protriptyline and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.quazepamMonitor Closely (1)quazepam and haloperidol both increase sedation. Use Caution/Monitor.quetiapineMonitor Closely (3)haloperidol and quetiapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. haloperidol and quetiapine both increase sedation. Use Caution/Monitor. quetiapine, haloperidol. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval. Postmarketing cases show QT prolongation with overdose in patients with concomitant illness or with drugs known to cause electrolyte imbalance or prolong QT.quinacrineMonitor Closely (1)quinacrine will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.quinidineContraindicated (1)quinidine and haloperidol both increase QTc interval. Contraindicated.Serious - Use Alternative (1)quinidine will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.quinineMonitor Closely (1)haloperidol and quinine both increase QTc interval. Use Caution/Monitor.quinupristin/dalfopristinSerious - Use Alternative (1)quinupristin/dalfopristin increases levels of haloperidol by decreasing metabolism. Contraindicated. Risk of prolonged QTc interval.ramelteonMonitor Closely (1)haloperidol and ramelteon both increase sedation. Use Caution/Monitor.ranolazineMonitor Closely (2)ranolazine will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. haloperidol and ranolazine both increase QTc interval. Modify Therapy/Monitor Closely.rapacuroniumMonitor Closely (3)rapacuronium decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. rapacuronium decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor. haloperidol increases effects of rapacuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.remimazolamMonitor Closely (1)remimazolam, haloperidol. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely. Coadministration may result in profound sedation, respiratory depression, coma, and/or death. Continuously monitor vital signs during sedation and recovery period if coadministered. Carefully titrate remimazolam dose if administered with opioid analgesics and/or sedative/hypnotics.ribociclibMonitor Closely (1)ribociclib will increase the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)ribociclib and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.rifabutinMonitor Closely (1)rifabutin will decrease the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.rifampinMonitor Closely (1)rifampin will decrease the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.rifapentineMonitor Closely (1)rifapentine will decrease the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.rilpivirineMonitor Closely (1)rilpivirine increases toxicity of haloperidol by QTc interval. Use Caution/Monitor. Rilpivirine should be used with caution when co-administered with a drug with a known risk of Torsades de Pointes.rimabotulinumtoxinBMonitor Closely (1)haloperidol, rimabotulinumtoxinB. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Anticholinergics may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.rimegepantMonitor Closely (1)haloperidol will increase the level or effect of rimegepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Avoid repeating rimegepant dose within 48 hr if coadministered with a moderate CYP3A4 inhibitor.risperidoneMonitor Closely (3)haloperidol and risperidone both increase QTc interval. Modify Therapy/Monitor Closely. haloperidol and risperidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. haloperidol and risperidone both increase sedation. Use Caution/Monitor.Minor (1)haloperidol will increase the level or effect of risperidone by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.ritonavirMonitor Closely (3)ritonavir will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. ritonavir will increase the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. haloperidol and ritonavir both increase QTc interval. Use Caution/Monitor.rizatriptanMonitor Closely (1)rizatriptan, haloperidol. 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).rocuroniumMonitor Closely (3)rocuronium decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. rocuronium decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor. haloperidol increases effects of rocuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.rolapitantMonitor Closely (1)rolapitant will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Rolapitant may increase plasma concentrations of CYP2D6 substrates for at least 28 days following rolapitant administration.romidepsinSerious - Use Alternative (1)haloperidol and romidepsin both increase QTc interval. Avoid or Use Alternate Drug.ropeginterferon alfa 2bSerious - Use Alternative (1)ropeginterferon alfa 2b, haloperidol. Either increases toxicity of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Myelosuppressive agents can produce additive myelosuppression. Avoid use and monitor patients receiving the combination for effects of excessive myelosuppression.ropiniroleSerious - Use Alternative (1)haloperidol decreases effects of ropinirole by pharmacodynamic antagonism. Contraindicated.rucaparibMonitor Closely (1)rucaparib will increase the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.ruxolitinibMonitor Closely (1)haloperidol will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ruxolitinib topicalMonitor Closely (1)haloperidol will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.safinamideSerious - Use Alternative (1)haloperidol decreases effects of safinamide by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Dopamine antagonists may decrease safinamide effects and exacerbate Parkinson disease symptoms.sageMinor (1)haloperidol and sage both increase sedation. Minor/Significance Unknown.salmeterolMonitor Closely (1)haloperidol increases and salmeterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.saquinavirSerious - Use Alternative (2)saquinavir increases levels of haloperidol by QTc interval. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias. saquinavir increases levels of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.scopolamineMonitor Closely (3)scopolamine decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. scopolamine decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor. haloperidol increases effects of scopolamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.scullcapMonitor Closely (1)haloperidol and scullcap both increase sedation. Use Caution/Monitor.secobarbitalMonitor Closely (1)secobarbital and haloperidol both increase sedation. Use Caution/Monitor.Minor (1)haloperidol, secobarbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hyperthermia if haloperidol admin. during barbiturate withdrawal.selegilineMonitor Closely (1)selegiline, haloperidol. 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).selinexorSerious - Use Alternative (1)selinexor, haloperidol. unspecified interaction mechanism. Avoid or Use Alternate Drug. Patients treated with selinexor may experience neurological toxicities. Avoid taking selinexor with other medications that may cause dizziness or confusion.selpercatinibMonitor Closely (1)selpercatinib increases toxicity of haloperidol by QTc interval. Use Caution/Monitor.selumetinibSerious - Use Alternative (1)haloperidol will increase the level or effect of selumetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong or moderate CYP3A4 inhibitors cannot be avoided, reduce selumetinib dosage (refer to selumetinib monograph for further information). After discontinuation of the strong or moderate CYP3A4 inhibitor for 3 elimination half-lives, resume selumetinib dose that was taken before initiating the inhibitor.sertralineMonitor Closely (2)sertraline will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. haloperidol and sertraline both increase QTc interval. Use Caution/Monitor.sevofluraneMonitor Closely (1)sevoflurane and haloperidol both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)sevoflurane and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.shepherd's purseMonitor Closely (1)haloperidol and shepherd's purse both increase sedation. Use Caution/Monitor.siponimodSerious - Use Alternative (2)haloperidol will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended. siponimod and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.sodium oxybateSerious - Use Alternative (1)haloperidol, sodium oxybate. Either increases effects 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.sodium sulfate/?magnesium sulfate/potassium chlorideMonitor Closely (1)sodium sulfate/?magnesium sulfate/potassium chloride increases effects of haloperidol by unknown mechanism. Use Caution/Monitor. Closely monitor for evidence of enhanced CNS depression when using higher dose of magnesium sulfate together with a CNS depressant.sodium sulfate/potassium sulfate/magnesium sulfateMonitor Closely (1)sodium sulfate/potassium sulfate/magnesium sulfate increases effects of haloperidol by unknown mechanism. Use Caution/Monitor. Closely monitor for evidence of enhanced CNS depression when using higher dose of magnesium sulfate together with a CNS depressant.solifenacinMonitor Closely (4)solifenacin decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. solifenacin decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor. haloperidol increases effects of solifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. haloperidol and solifenacin both increase QTc interval. Use Caution/Monitor.sonidegibMonitor Closely (1)haloperidol will increase the level or effect of sonidegib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Avoid coadministration of sonidegib with moderate CYP3A4 inhibitors. If a moderate CYP3A inhibitor must be used, administer the moderate CYP3A inhibitor for <14 days and monitor closely for adverse reactions, particularly musculoskeletal adverse reactions.sorafenibMonitor Closely (1)sorafenib and haloperidol both increase QTc interval. Use Caution/Monitor.sotalolContraindicated (1)haloperidol and sotalol both increase QTc interval. Contraindicated.sparsentanMonitor Closely (1)haloperidol will increase the level or effect of sparsentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment needed. Monitor blood pressure, serum potassium, edema, and kidney function regularly if sparsentan is coadministered with moderate CYP3A4 inhibitors. stiripentolMonitor Closely (2)stiripentol, haloperidol. 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. stiripentol, haloperidol. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.sufentanilMonitor Closely (1)sufentanil and haloperidol both increase sedation. Use Caution/Monitor.sufentanil SLMonitor Closely (1)haloperidol will increase the level or effect of sufentanil SL by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of sufentanil SL with any CYP3A4 inhibitor may increase sufentanil plasma concentration, and, thereby increase or prolonged adverse effects, including potentially fatal respiratory depression.Serious - Use Alternative (1)sufentanil SL, haloperidol. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration may result in hypotension, profound sedation, respiratory depression, coma, and death. 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.sulfamethoxazoleMonitor Closely (1)sulfamethoxazole and haloperidol both increase QTc interval. Modify Therapy/Monitor Closely.sumatriptanMonitor Closely (1)sumatriptan, haloperidol. 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 intranasalMonitor Closely (1)sumatriptan intranasal, haloperidol. 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).sunitinibMonitor Closely (1)haloperidol and sunitinib both increase QTc interval. Use Caution/Monitor.suvorexantMonitor Closely (1)haloperidol will increase the level or effect of suvorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Decrease suvorexant starting dose to 5 mg HS if coadministered with moderate CYP3A4 inhibitorstacrolimusMonitor Closely (1)haloperidol and tacrolimus both increase QTc interval.