hydrocodone [benzhydrocodone is prodrug of hydrocodone]) is mainly formed by CYP2D6 mediated O-demethylation of hydrocodone. Hydromorphone may contribute to the total analgesic effect of hydrocodone. benzhydrocodone/acetaminophen and haloperidol both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)benzhydrocodone/acetaminophen, haloperidol. Either increases toxicity 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.benzphetamineMonitor Closely (1)haloperidol increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.benztropineMonitor Closely (1)haloperidol increases effects of benztropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic adverse effects may be seen with concurrent use. .bosentanMonitor Closely (1)bosentan will decrease the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.bosutinibMonitor Closely (1)bosutinib and haloperidol both increase QTc interval. Use Caution/Monitor.Serious - Use Alternative (1)haloperidol increases levels of bosutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.brexanoloneMonitor Closely (1)brexanolone, haloperidol. Either increases toxicity of the other by sedation. Use Caution/Monitor.brexpiprazoleMonitor 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.brimonidineMonitor Closely (1)brimonidine and haloperidol both increase sedation. Use Caution/Monitor.Minor (1)brimonidine increases effects of haloperidol by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.brivaracetamMonitor Closely (1)brivaracetam and haloperidol both increase sedation. Use Caution/Monitor.bromocriptineSerious - Use Alternative (1)haloperidol decreases effects of bromocriptine by pharmacodynamic antagonism. Avoid or Use Alternate Drug.brompheniramineMonitor Closely (1)brompheniramine and haloperidol both increase sedation. Use Caution/Monitor.buprenorphineMonitor Closely (1)buprenorphine and haloperidol both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)buprenorphine and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.buprenorphine buccalMonitor Closely (1)buprenorphine buccal and haloperidol both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)buprenorphine buccal and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.buprenorphine subdermal implantMonitor Closely (2)buprenorphine subdermal implant and haloperidol both increase sedation. Use Caution/Monitor. haloperidol will increase the level or effect of buprenorphine subdermal implant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor patients already on buprenorphine subdermal implant who require newly-initiated treatment with CYP3A4 inhibitors for signs and symptoms of overmedication. If the dose of the concomitant CYP3A4 inhibitor cannot be reduced or discontinued, implant removal may be necessary and the patient should then be treated with a buprenorphine dosage form that permits dose adjustments. If a CYP3A4 inhibitor is discontinued in a patient who has been stabilized on buprenorphine, monitor the patient for withdrawal.Serious - Use Alternative (1)buprenorphine subdermal implant and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.buprenorphine transdermalMonitor Closely (1)buprenorphine transdermal and haloperidol both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)buprenorphine transdermal and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.buprenorphine, long-acting injectionMonitor Closely (3)buprenorphine, long-acting injection and haloperidol both increase sedation. Use Caution/Monitor. haloperidol will increase the level or effect of buprenorphine, long-acting injection by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Patients who transfer to buprenorphine long-acting injection from transmucosal buprenorphine coadministered with CYP3A4 inhibitors should be monitored to ensure buprenorphine plasma levels are adequate. Within 2 weeks, if signs and symptoms of buprenorphine toxicity or overdose occur and the concomitant CYP3A4 inhibitor cannot be reduced or discontinued, transition the patient back to a buprenorphine formulation that permits dose adjustments. haloperidol increases toxicity of buprenorphine, long-acting injection by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of buprenorphine and benzodiazepines or other CNS depressants increases risk of adverse reactions including overdose, respiratory depression, and death. Cessation of benzodiazepines or other CNS depressants is preferred in most cases. In some cases, monitoring at a higher level of care for tapering CNS depressants may be appropriate. In others, gradually tapering a patient off of a prescribed benzodiazepine or other CNS depressant or decreasing to the lowest effective dose may be appropriate.Serious - Use Alternative (1)buprenorphine, long-acting injection and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.bupropionMonitor Closely (1)bupropion will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.butabarbitalMonitor Closely (1)butabarbital and haloperidol both increase sedation. Use Caution/Monitor.Minor (1)haloperidol, butabarbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hyperthermia if haloperidol admin. during barbiturate withdrawal.butalbitalMonitor Closely (1)butalbital and haloperidol both increase sedation. Use Caution/Monitor.Minor (1)haloperidol, butalbital. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hyperthermia if haloperidol admin. during barbiturate withdrawal.butorphanolMonitor Closely (1)butorphanol and haloperidol both increase sedation. Use Caution/Monitor.cabergolineSerious - Use Alternative (1)haloperidol decreases effects of cabergoline by pharmacodynamic antagonism. Contraindicated.cabozantinibMonitor Closely (1)haloperidol will increase the level or effect of cabozantinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.caffeineMonitor Closely (1)haloperidol increases and caffeine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.calcium/magnesium/potassium/sodium oxybatesSerious - Use Alternative (1)haloperidol, calcium/magnesium/potassium/sodium oxybates. 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.cannabidiolMonitor Closely (1)haloperidol will increase the level or effect of cannabidiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Consider reducing the cannabidiol dose when coadministered with a moderate CYP3A4 inhibitor.capecitabineMonitor Closely (1)capecitabine and haloperidol both increase QTc interval. Use Caution/Monitor.carbamazepineMonitor Closely (1)carbamazepine decreases levels of haloperidol by increasing metabolism. Use Caution/Monitor.Serious - Use Alternative (1)carbamazepine will decrease the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.carbinoxamineMonitor Closely (1)carbinoxamine and haloperidol both increase sedation. Use Caution/Monitor.carisoprodolMonitor Closely (1)carisoprodol and haloperidol both increase sedation. Use Caution/Monitor.carvedilolMonitor Closely (1)haloperidol will increase the level or effect of carvedilol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.celecoxibMonitor Closely (1)celecoxib will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.cenobamateMonitor Closely (1)cenobamate will decrease the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.ceritinibSerious - Use Alternative (2)ceritinib and haloperidol both increase QTc interval. Avoid or Use Alternate Drug. ceritinib will increase the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.chasteberryMinor (1)chasteberry decreases effects of haloperidol by pharmacodynamic antagonism. Minor/Significance Unknown. (Theoretical interaction).chloral hydrateMonitor Closely (1)chloral hydrate and haloperidol both increase sedation. Use Caution/Monitor.chloramphenicolSerious - Use Alternative (1)chloramphenicol will increase the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.chlordiazepoxideMonitor Closely (1)chlordiazepoxide and haloperidol both increase sedation. Use Caution/Monitor.chloroquineMonitor Closely (2)chloroquine will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. chloroquine increases toxicity of haloperidol by QTc interval. Use Caution/Monitor.chlorpheniramineMonitor Closely (1)chlorpheniramine and haloperidol both increase sedation. Use Caution/Monitor.chlorpromazineMonitor Closely (2)chlorpromazine and haloperidol both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. chlorpromazine and haloperidol both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)haloperidol will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.chlorzoxazoneMonitor Closely (1)chlorzoxazone and haloperidol both increase sedation. Use Caution/Monitor.cimetidineMonitor Closely (1)cimetidine will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.cinnarizineMonitor Closely (1)cinnarizine and haloperidol both increase sedation. Use Caution/Monitor.ciprofloxacinMonitor Closely (1)ciprofloxacin and haloperidol both increase QTc interval. Use Caution/Monitor. Ciprofloxacin elicits minimal effects on QT interval. Caution if used in combination with other drugs known to affect QT interval or in patients with other risk factors.cisatracuriumMonitor Closely (3)cisatracurium decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. cisatracurium decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor. haloperidol increases effects of cisatracurium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.citalopramSerious - Use Alternative (2)citalopram will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Increased risk of serotonin syndrome or neuroleptic malignant syndrome. Potential risk for QT prolongation. ECG monitoring is recommended. citalopram and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.clarithromycinSerious - Use Alternative (2)clarithromycin and haloperidol both increase QTc interval. Avoid or Use Alternate Drug. clarithromycin will increase the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.clemastineMonitor Closely (1)clemastine and haloperidol both increase sedation. Use Caution/Monitor.clobazamMonitor Closely (1)clobazam will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Lower doses of drugs metabolized by CYP2D6 may be required when used concomitantly. clomipramineMonitor Closely (1)haloperidol and clomipramine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (2)clomipramine and haloperidol both increase QTc interval. Avoid or Use Alternate Drug. haloperidol will increase the level or effect of clomipramine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.clonazepamMonitor Closely (1)clonazepam and haloperidol both increase sedation. Use Caution/Monitor.clonidineMonitor Closely (2)clonidine, haloperidol. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects; potential delirium. clonidine increases toxicity of haloperidol by Other (see comment). Use Caution/Monitor. Comment: High doses of clonidine IV may increase arrhythmogenic potential (QT-prolongation, ventricular fibrillation) of high dose haloperidol IV in patients experiencing alcoholic delirium.clorazepateMonitor Closely (1)clorazepate and haloperidol both increase sedation. Use Caution/Monitor.clozapineMonitor Closely (3)clozapine and haloperidol both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. clozapine and haloperidol both increase sedation. Use Caution/Monitor. haloperidol and clozapine both increase QTc interval. Use Caution/Monitor.cobicistatMonitor Closely (1)cobicistat will increase the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.cobimetinibSerious - Use Alternative (1)haloperidol will increase the level or effect of cobimetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If concurrent short term (14 days or less) use of moderate CYP3A inhibitors is unavoidable for patients who are taking cobimetinib 60 mg, reduce the cobimetinib dose to 20 mg. After discontinuation of a moderate CYP3A inhibitor, resume cobimetinib 60 mg. Use an alternative to a moderate CYP3A inhibitor in patients who are taking a reduced dose of cobimetinib (40 or 20 mg daily).codeineMonitor Closely (2)haloperidol decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine. codeine and haloperidol both increase sedation. Use Caution/Monitor.conivaptanMonitor Closely (1)conivaptan will increase the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.crizotinibMonitor Closely (1)crizotinib increases levels of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A. ECG monitoring is recommended, along with drugs that may prolong the QT interval.Serious - Use Alternative (1)crizotinib and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.crofelemerMonitor Closely (1)crofelemer increases levels of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.cyclizineMonitor Closely (4)cyclizine decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. cyclizine decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor. haloperidol increases effects of cyclizine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. cyclizine and haloperidol both increase sedation. Use Caution/Monitor.cyclobenzaprineMonitor Closely (4)cyclobenzaprine decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. cyclobenzaprine decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor. haloperidol increases effects of cyclobenzaprine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. cyclobenzaprine and haloperidol both increase sedation. Use Caution/Monitor.cyclophosphamideMinor (1)cyclophosphamide will increase the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.cyproheptadineMonitor Closely (1)cyproheptadine and haloperidol both increase sedation. Use Caution/Monitor.dabrafenibMonitor Closely (2)dabrafenib and haloperidol both increase QTc interval. Use Caution/Monitor. dabrafenib will decrease the level or effect of haloperidol