will increase the level or effect of estradiol vaginal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.ethanolethanol, haloperidol. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive CNS depression.eucalyptushaloperidol and eucalyptus both increase sedation. Minor/Significance Unknown.fesoterodinehaloperidol will increase the level or effect of fesoterodine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.fluphenazinehaloperidol will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.galantaminehaloperidol will increase the level or effect of galantamine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.indomethacinindomethacin increases toxicity of haloperidol by unknown mechanism. Minor/Significance Unknown.irinotecanhaloperidol will increase the level or effect of irinotecan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.irinotecan liposomalhaloperidol will increase the level or effect of irinotecan liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.larotrectiniblarotrectinib will increase the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.loratadinehaloperidol will increase the level or effect of loratadine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.metyrosinemetyrosine increases effects of haloperidol by pharmacodynamic synergism. Minor/Significance Unknown.oliceridinehaloperidol will increase the level or effect of oliceridine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. If concomitant use is necessary, may require less frequent oliceridine dosing. Closely monitor for respiratory depression and sedation and titrate subsequent doses accordingly. If inhibitor is discontinued, consider increase oliceridine dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal. oxycodonehaloperidol decreases effects of oxycodone by decreasing metabolism. Minor/Significance Unknown. Decreased conversion of oxycodone to active metabolite morphine.pentobarbitalhaloperidol, pentobarbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hyperthermia if haloperidol admin. during barbiturate withdrawal.perhexilinehaloperidol will increase the level or effect of perhexiline by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.perphenazinehaloperidol will increase the level or effect of perphenazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.phenobarbitalhaloperidol, phenobarbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hyperthermia if haloperidol admin. during barbiturate withdrawal.primidonehaloperidol, primidone. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hyperthermia if haloperidol admin. during barbiturate withdrawal.prochlorperazinehaloperidol will increase the level or effect of prochlorperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.promazinehaloperidol will increase the level or effect of promazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.promethazinehaloperidol will increase the level or effect of promethazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.risperidonehaloperidol will increase the level or effect of risperidone by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.sagehaloperidol and sage both increase sedation. Minor/Significance Unknown.secobarbitalhaloperidol, secobarbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hyperthermia if haloperidol admin. during barbiturate withdrawal.tolterodinehaloperidol will increase the level or effect of tolterodine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.trifluoperazinehaloperidol will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.tropisetronhaloperidol will increase the level or effect of tropisetron by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.abametapirSerious - Use Alternative (1)abametapir will increase the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP3A4 substrates. If not feasible, avoid use of abametapir.abirateroneMonitor Closely (1)abiraterone increases levels of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Avoid coadministration of abiraterone with substrates of CYP2D6. If alternative therapy cannot be used, exercise caution and consider a dose reduction of the CYP2D6 substrate.abobotulinumtoxinAMonitor Closely (1)abobotulinumtoxinA increases effects of haloperidol by pharmacodynamic synergism. Use Caution/Monitor. Use of anticholinergic drugs after administration of botulinum toxin-containing products may potentiate systemic anticholinergic effects.acalabrutinibMonitor Closely (2)acalabrutinib, haloperidol. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may increase risk of myelosuppressive effects. haloperidol will increase the level or effect of acalabrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Decrease acalabrutinib dose to 100 mg once daily if coadministered with a moderate CYP3A inhibitor.acetazolamideMinor (1)acetazolamide will increase the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.aclidiniumMonitor Closely (2)aclidinium decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor. haloperidol increases effects of aclidinium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.acrivastineMonitor Closely (1)acrivastine and haloperidol both increase sedation. Use Caution/Monitor.adagrasibSerious - Use Alternative (1)adagrasib, haloperidol. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Each drug prolongs the QTc interval, which may increased the risk of Torsade de pointes, other serious arryhthmias, and sudden death. If coadministration unavoidable, more frequent monitoring is recommended for such patients.albuterolMonitor Closely (2)albuterol and haloperidol both increase QTc interval. Use Caution/Monitor. haloperidol increases and albuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.alfentanilMonitor Closely (1)alfentanil and haloperidol both increase sedation. Use Caution/Monitor.alfuzosinMonitor Closely (2)alfuzosin and haloperidol both increase QTc interval. Use Caution/Monitor. haloperidol and alfuzosin both increase QTc interval. Use Caution/Monitor.almotriptanMonitor Closely (1)almotriptan, 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).alprazolamMonitor Closely (1)alprazolam and haloperidol both increase sedation. Use Caution/Monitor.amifampridineMonitor Closely (1)haloperidol increases toxicity of amifampridine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Amifampridine can cause seizures. Coadministration with drugs that lower seizure threshold may increase this risk.amiodaroneSerious - Use Alternative (1)amiodarone and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.amisulprideContraindicated (1)amisulpride, haloperidol. Either increases toxicity of the other by Other (see comment). Contraindicated. Comment: Increases risk of neuroleptic malignant syndrome.Serious - Use Alternative (1)amisulpride and haloperidol both increase QTc interval. Avoid or Use Alternate Drug. ECG monitoring is recommended if coadministered.amitriptylineMonitor Closely (1)haloperidol and amitriptyline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)amitriptyline and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.amobarbitalMonitor Closely (2)amobarbital and haloperidol both increase sedation. Use Caution/Monitor. amobarbital will decrease the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)haloperidol, amobarbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hyperthermia if haloperidol admin. during barbiturate withdrawal.amoxapineMonitor Closely (2)haloperidol and amoxapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Modify Therapy/Monitor Closely. haloperidol and amoxapine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)amoxapine and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.anagrelideSerious - Use Alternative (1)anagrelide and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.anastrozoleMinor (1)anastrozole will increase the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.anticholinergic/sedative combosMonitor Closely (3)anticholinergic/sedative combos decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. anticholinergic/sedative combos decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor. haloperidol increases effects of anticholinergic/sedative combos by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.apalutamideSerious - Use Alternative (1)apalutamide will decrease the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.apomorphineMonitor Closely (2)haloperidol and apomorphine both increase sedation. Use Caution/Monitor. haloperidol and apomorphine both increase QTc interval. Use Caution/Monitor.Serious - Use Alternative (1)haloperidol decreases effects of apomorphine by pharmacodynamic antagonism. Avoid or Use Alternate Drug.arformoterolMonitor Closely (2)haloperidol increases and arformoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. haloperidol and arformoterol both increase QTc interval. Use Caution/Monitor.aripiprazoleMonitor Closely (3)aripiprazole and haloperidol both increase QTc interval. Use Caution/Monitor. aripiprazole and haloperidol both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. aripiprazole and haloperidol both increase sedation. Use Caution/Monitor.Minor (1)haloperidol will increase the level or effect of aripiprazole by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.armodafinilMonitor Closely (1)haloperidol increases and armodafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.arsenic trioxideSerious - Use Alternative (1)arsenic trioxide and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.artemetherMonitor Closely (1)haloperidol and artemether both increase QTc interval. Use Caution/Monitor.artemether/lumefantrineSerious - Use Alternative (2)haloperidol and artemether/lumefantrine both increase QTc interval. Avoid or Use Alternate Drug. artemether/lumefantrine will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.asenapineMonitor Closely (3)asenapine will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. asenapine and haloperidol both increase sedation. Use Caution/Monitor. haloperidol and asenapine both increase QTc interval. Use Caution/Monitor.asenapine transdermalMonitor Closely (2)asenapine transdermal and haloperidol both increase QTc interval. Use Caution/Monitor. asenapine transdermal and haloperidol both increase sedation. Use Caution/Monitor.atazanavirMonitor Closely (1)atazanavir will increase the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.atogepantMonitor Closely (1)haloperidol will increase the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.atomoxetineMonitor Closely (2)atomoxetine and haloperidol both increase QTc interval. Use Caution/Monitor. haloperidol will increase the level or effect of atomoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.atracuriumMonitor Closely (3)atracurium decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. atracurium decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor. haloperidol increases effects of atracurium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.atropineMonitor Closely (3)atropine decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. atropine decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor. haloperidol increases effects of atropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.atropine IV/IMMonitor Closely (3)haloperidol increases effects of atropine IV/IM by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. atropine IV/IM decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. atropine IV/IM decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor.avanafilMonitor Closely (1)haloperidol will increase the level or effect of avanafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inhibitors may reduce avanafil clearance increasing systemic exposure to avanafil; increased levels may result in increased associated adverse events; the maximum recommended dose of STENDRA is 50 mg, not to exceed once every 24 hours for patients taking concomitant moderate CYP3A4 inhibitorsavapritinibMonitor Closely (1)avapritinib and haloperidol both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)haloperidol will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of avapritinib with moderate CYP3A4 inhibitors. If unable to avoid, reduce avapritinib starting dose. See drug monograph Dosage Modifications.axitinibSerious - Use Alternative (1)haloperidol increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with moderate CYP3A4 inhibitors, monitor closely and reduce dose if necessary .azelastineMonitor Closely (1)azelastine and haloperidol both increase sedation. Use Caution/Monitor.azithromycinMonitor Closely (1)azithromycin and haloperidol both increase QTc interval. Use Caution/Monitor.baclofenMonitor Closely (1)baclofen and haloperidol both increase sedation. Use Caution/Monitor.bedaquilineMonitor Closely (1)haloperidol and bedaquiline both increase QTc interval. Modify Therapy/Monitor Closely. ECG should be monitored closelybelladonna alkaloidsMonitor Closely (3)belladonna alkaloids decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. belladonna alkaloids decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor. haloperidol increases effects of belladonna alkaloids by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.belladonna and opiumMonitor Closely (4)belladonna and opium decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. belladonna and opium decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor. haloperidol increases effects of belladonna and opium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. belladonna and opium and haloperidol both increase sedation. Use Caution/Monitor.belzutifanMonitor Closely (1)belzutifan will decrease the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If unable to avoid coadministration of belzutifan with sensitive CYP3A4 substrates, consider increasing the sensitive CYP3A4 substrate dose in accordance with its prescribing information. benperidolMonitor Closely (2)benperidol and haloperidol both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. benperidol and haloperidol both increase sedation. Use Caution/Monitor.benzhydrocodone/acetaminophenMonitor Closely (2)haloperidol will increase the level or effect of benzhydrocodone/acetaminophen by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Hydromorphone (<3% of the circulating parent