chlorpromazine and loxapine inhaled both increase sedation. Use Caution/Monitor.lumefantrineMonitor Closely (1)lumefantrine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and lumefantrine both increase QTc interval. Avoid or Use Alternate Drug.lurasidoneMonitor Closely (1)lurasidone, chlorpromazine. 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 chlorpromazine 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.maprotilineMonitor Closely (1)chlorpromazine and maprotiline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and maprotiline both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)maprotiline, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects. maprotiline, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.maravirocMinor (1)maraviroc will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.marijuanaMonitor Closely (1)chlorpromazine and marijuana both increase sedation. Use Caution/Monitor.Minor (1)marijuana will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.meclizineMonitor Closely (3)meclizine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. meclizine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor. chlorpromazine increases effects of meclizine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.melatoninMonitor Closely (1)chlorpromazine and melatonin both increase sedation. Use Caution/Monitor.meperidineMonitor Closely (1)meperidine and chlorpromazine both increase sedation. Use Caution/Monitor.meprobamateMonitor Closely (1)chlorpromazine and meprobamate both increase sedation. Use Caution/Monitor.metaproterenolMonitor Closely (1)chlorpromazine increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.metaxaloneMonitor Closely (1)metaxalone and chlorpromazine both increase sedation. Use Caution/Monitor.metforminMonitor Closely (1)chlorpromazine decreases effects of metformin by pharmacodynamic antagonism. Use Caution/Monitor. Patient should be closely observed for loss of blood glucose control; when drugs are withdrawn from a patient receiving metformin, patient should be observed closely for hypoglycemia.methadoneMonitor Closely (2)chlorpromazine and methadone both increase QTc interval. Modify Therapy/Monitor Closely. methadone and chlorpromazine both increase sedation. Use Caution/Monitor.methamphetamineMonitor Closely (2)chlorpromazine, methamphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only. chlorpromazine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.methocarbamolMonitor Closely (1)methocarbamol and chlorpromazine both increase sedation. Use Caution/Monitor.methoxsalenMonitor Closely (1)methoxsalen, chlorpromazine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive photosensitizing effects.methscopolamineMonitor Closely (3)methscopolamine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. methscopolamine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor. chlorpromazine increases effects of methscopolamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.methyl aminolevulinateSerious - Use Alternative (1)chlorpromazine, methyl aminolevulinate. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Each drug may increase the photosensitizing effect of the other.methyldopaSerious - Use Alternative (1)chlorpromazine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.methylenedioxymethamphetamineMonitor Closely (2)chlorpromazine, methylenedioxymethamphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only. chlorpromazine increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.methylphenidateMonitor Closely (1)chlorpromazine, methylphenidate. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.metoclopramideMonitor Closely (1)chlorpromazine and metoclopramide both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.metoclopramide intranasalSerious - Use Alternative (2)chlorpromazine, 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. chlorpromazine increases toxicity of metoclopramide intranasal by pharmacodynamic synergism. Avoid or Use Alternate Drug. Potential for additive effects, including increased frequency and severity of tardive dyskinesia, other extrapyramidal symptoms, and neuroleptic malignant syndrome.metoprololSerious - Use Alternative (1)metoprolol, chlorpromazine. Either increases levels of the other by decreasing metabolism. Contraindicated. Not all beta blockers share this interaction (e.g., atenolol, nadolol, sotalol do not interact).metrizamideContraindicated (1)chlorpromazine, metrizamide. Mechanism: unknown. Contraindicated. Risk of seizure. D/C phenothiazine 24h before admin. of metrizamide.metyraponeMinor (1)chlorpromazine decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.metyrosineMinor (1)metyrosine increases toxicity of chlorpromazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased extrapyramidal symptoms.midazolamMonitor Closely (1)midazolam and chlorpromazine both increase sedation. Use Caution/Monitor.midazolam intranasalMonitor Closely (1)midazolam intranasal, chlorpromazine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase the risk of hypoventilation, airway obstruction, desaturation, or apnea and may contribute to profound and/or prolonged drug effect.midodrineMonitor Closely (2)chlorpromazine, midodrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only. chlorpromazine increases and midodrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.mifepristoneMonitor Closely (1)mifepristone, chlorpromazine. QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available.mipomersenMonitor Closely (1)mipomersen, chlorpromazine. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Both drugs have potential to increase hepatic enzymes; monitor LFTs.mirabegronMonitor Closely (1)mirabegron will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.mirtazapineMonitor Closely (1)chlorpromazine and mirtazapine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)mirtazapine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.mobocertinibSerious - Use Alternative (1)mobocertinib and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, reduce mobocertinib dose and monitor QTc interval more frequently.modafinilMonitor Closely (1)chlorpromazine increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.moexiprilMinor (1)chlorpromazine increases effects of moexipril by unspecified interaction mechanism. Minor/Significance Unknown.morphineMonitor Closely (1)morphine and chlorpromazine both increase sedation. Use Caution/Monitor.motherwortMonitor Closely (1)chlorpromazine and motherwort both increase sedation. Use Caution/Monitor.moxifloxacinSerious - Use Alternative (1)chlorpromazine and moxifloxacin both increase QTc interval. Avoid or Use Alternate Drug.moxonidineMonitor Closely (1)chlorpromazine and moxonidine both increase sedation. Use Caution/Monitor.nabiloneMonitor Closely (1)chlorpromazine and nabilone both increase sedation. Use Caution/Monitor.nalbuphineMonitor Closely (1)nalbuphine and chlorpromazine both increase sedation. Use Caution/Monitor.nilotinibSerious - Use Alternative (1)chlorpromazine and nilotinib both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)nilotinib will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.norepinephrineMonitor Closely (2)chlorpromazine, norepinephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only. chlorpromazine increases and norepinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.nortriptylineMonitor Closely (1)chlorpromazine and nortriptyline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and nortriptyline both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)nortriptyline, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects. nortriptyline, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.octreotideSerious - Use Alternative (1)chlorpromazine and octreotide both increase QTc interval. Avoid or Use Alternate Drug.octreotide (Antidote)Serious - Use Alternative (1)chlorpromazine and octreotide (Antidote) both increase QTc interval. Avoid or Use Alternate Drug.ofloxacinMonitor Closely (1)chlorpromazine and ofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.olanzapineMonitor Closely (2)chlorpromazine and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. chlorpromazine and olanzapine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)olanzapine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.oliceridineMonitor Closely (1)oliceridine, chlorpromazine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. 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. Increased risk of hypotension if ability to maintain blood pressure has been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (eg, phenothiazines or general anesthetics).olodaterol inhaledMonitor Closely (1)chlorpromazine and olodaterol inhaled both increase QTc interval. Use Caution/Monitor. Drugs that prolong the QTc interval and may potentiate the effects of beta2 agonists on the cardiovascular system; increased risk of ventricular arrhythmiasolopatadine intranasalSerious - Use Alternative (1)chlorpromazine and olopatadine intranasal both increase sedation. Avoid or Use Alternate Drug. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment. onabotulinumtoxinAMonitor Closely (3)onabotulinumtoxinA decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. onabotulinumtoxinA decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor. chlorpromazine increases effects of onabotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.ondansetronSerious - Use Alternative (1)chlorpromazine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.opium tinctureMonitor Closely (1)opium tincture and chlorpromazine both increase sedation. Use Caution/Monitor.orphenadrineMonitor Closely (1)orphenadrine and chlorpromazine both increase sedation. Use Caution/Monitor.Minor (1)orphenadrine decreases levels of chlorpromazine by unknown mechanism. Minor/Significance Unknown. Excessive anticholinergic effects and/or hypoglycemia possible.osilodrostatMonitor Closely (1)osilodrostat and chlorpromazine both increase QTc interval. Use Caution/Monitor.osimertinibMonitor Closely (1)osimertinib and chlorpromazine both increase QTc interval. Use Caution/Monitor. Conduct periodic monitoring with ECGs and electrolytes in patients taking drugs known to prolong the QTc interval.oxaliplatinMonitor Closely (1)oxaliplatin will increase the level or effect of chlorpromazine by Other (see comment). Use Caution/Monitor. Monitor for ECG changes if therapy is initiated in patients with drugs known to prolong QT interval.Serious - Use Alternative (1)oxaliplatin and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.oxazepamMonitor Closely (1)oxazepam and chlorpromazine both increase sedation. Use Caution/Monitor.oxybutyninMonitor Closely (3)oxybutynin decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. oxybutynin decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor. chlorpromazine increases effects of oxybutynin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)oxybutynin increases toxicity of chlorpromazine by unspecified interaction mechanism. Minor/Significance Unknown.oxybutynin topicalMonitor Closely (3)oxybutynin topical decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. oxybutynin topical decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor. chlorpromazine increases effects of oxybutynin topical by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)oxybutynin topical increases toxicity of chlorpromazine by unspecified interaction mechanism. Minor/Significance Unknown.oxybutynin transdermalMonitor Closely (3)oxybutynin transdermal decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. oxybutynin transdermal decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor. chlorpromazine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)oxybutynin transdermal increases toxicity of chlorpromazine by unspecified interaction mechanism. Minor/Significance Unknown.oxycodoneMonitor Closely (1)oxycodone and chlorpromazine both increase sedation. Use Caution/Monitor.oxymorphoneMonitor Closely (1)oxymorphone and chlorpromazine both increase sedation. Use Caution/Monitor.ozanimodMonitor Closely (1)ozanimod and chlorpromazine both increase QTc interval. Modify Therapy/Monitor Closely. The potential additive effects on heart rate, treatment with ozanimod should generally not be initiated in patients who are concurrently treated with QT prolonging drugs with known arrhythmogenic properties.paliperidoneMonitor Closely (3)chlorpromazine and paliperidone both increase QTc interval. Modify Therapy/Monitor Closely. chlorpromazine and paliperidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. chlorpromazine and paliperidone both increase sedation. Use Caution/Monitor.pancuroniumMonitor Closely (3)pancuronium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. pancuronium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor. chlorpromazine increases effects of pancuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.panobinostatSerious - Use Alternative (1)chlorpromazine and panobinostat both increase QTc interval. Avoid or Use Alternate Drug. Panobinostat is known to significantly prolong QT interval. Panobinostat prescribing information states use with drugs known to prolong QTc is not recommended.papaveretumMonitor Closely (1)papaveretum and chlorpromazine both increase sedation. Use Caution/Monitor.papaverineMonitor Closely (1)chlorpromazine and papaverine both increase sedation. Use Caution/Monitor.parecoxibMinor (1)parecoxib will increase the level or effect of chlorpromazine by affecting hepatic enzyme