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).liraglutideMonitor Closely (1)fluphenazine, liraglutide. Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase or decrease glucose levels, monitor therapy closely when these agents are concurrently administered.lisdexamfetamineMonitor Closely (2)fluphenazine, lisdexamfetamine. 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. fluphenazine increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.lisinoprilMinor (1)fluphenazine increases effects of lisinopril by unspecified interaction mechanism. Minor/Significance Unknown.lisurideSerious - Use Alternative (1)fluphenazine decreases effects of lisuride by pharmacodynamic antagonism. Contraindicated.lithiumMonitor Closely (3)lithium, fluphenazine. Other (see comment). Use Caution/Monitor. Comment: Risk of neurotoxicity. Multiple mechanisms involved. lithium, fluphenazine. 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). lithium and fluphenazine both increase QTc interval. Use Caution/Monitor.lofepramineMonitor Closely (1)fluphenazine and lofepramine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)fluphenazine and lofepramine both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)lofepramine, fluphenazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects. lofepramine, fluphenazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.lofexidineMonitor Closely (1)fluphenazine and lofexidine both increase sedation. Use Caution/Monitor.loprazolamMonitor Closely (1)loprazolam and fluphenazine both increase sedation. Use Caution/Monitor.lorazepamMonitor Closely (1)lorazepam and fluphenazine both increase sedation. Use Caution/Monitor.lorcaserinMonitor Closely (2)lorcaserin will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. lorcaserin, fluphenazine. 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).lormetazepamMonitor Closely (1)lormetazepam and fluphenazine both increase sedation. Use Caution/Monitor.loxapineMonitor Closely (2)fluphenazine and loxapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. fluphenazine and loxapine both increase sedation. Use Caution/Monitor.loxapine inhaledMonitor Closely (2)fluphenazine and loxapine inhaled both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. fluphenazine and loxapine inhaled both increase sedation. Use Caution/Monitor.lumefantrineMonitor Closely (1)lumefantrine will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)fluphenazine and lumefantrine both increase QTc interval. Avoid or Use Alternate Drug.lurasidoneMonitor Closely (1)lurasidone, fluphenazine. 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 fluphenazine 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)fluphenazine and maprotiline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)fluphenazine and maprotiline both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)maprotiline, fluphenazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects. maprotiline, fluphenazine. 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 fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.marijuanaMonitor Closely (1)fluphenazine and marijuana both increase sedation. Use Caution/Monitor.Minor (1)marijuana will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.meclizineMonitor Closely (3)meclizine decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. meclizine decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor. fluphenazine increases effects of meclizine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.melatoninMonitor Closely (1)fluphenazine and melatonin both increase sedation. Use Caution/Monitor.meperidineMonitor Closely (2)meperidine, fluphenazine. 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 fluphenazine both increase sedation. Use Caution/Monitor.meprobamateMonitor Closely (1)fluphenazine and meprobamate both increase sedation. Use Caution/Monitor.metaproterenolMonitor Closely (1)fluphenazine increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.metaxaloneMonitor Closely (1)metaxalone and fluphenazine both increase sedation. Use Caution/Monitor.metforminMonitor Closely (1)fluphenazine 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 (3)methadone, fluphenazine. 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). fluphenazine and methadone both increase QTc interval. Modify Therapy/Monitor Closely. methadone and fluphenazine both increase sedation. Use Caution/Monitor.methamphetamineMonitor Closely (2)fluphenazine, 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. fluphenazine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.methocarbamolMonitor Closely (1)methocarbamol and fluphenazine both increase sedation. Use Caution/Monitor.methoxsalenMonitor Closely (1)methoxsalen, fluphenazine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive photosensitizing effects.methscopolamineMonitor Closely (3)methscopolamine decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. methscopolamine decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor. fluphenazine increases effects of methscopolamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.methyl aminolevulinateSerious - Use Alternative (1)fluphenazine, methyl aminolevulinate. Either increases levels 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)fluphenazine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.methylenedioxymethamphetamineMonitor Closely (2)fluphenazine, 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. fluphenazine increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.methylergonovineMonitor Closely (1)methylergonovine, fluphenazine. 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 (2)fluphenazine, 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. fluphenazine 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.metoclopramideMonitor Closely (1)fluphenazine and metoclopramide both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.metoclopramide intranasalSerious - Use Alternative (2)fluphenazine, 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. fluphenazine 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.metrizamideContraindicated (1)fluphenazine, metrizamide. Mechanism: unknown. Contraindicated. Risk of seizure. D/C phenothiazine 24h before admin. of metrizamide.metyraponeMinor (1)fluphenazine decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.metyrosineMinor (1)metyrosine increases toxicity of fluphenazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased extrapyramidal symptoms.midazolamMonitor Closely (1)midazolam and fluphenazine both increase sedation. Use Caution/Monitor.midazolam intranasalMonitor Closely (1)midazolam intranasal, fluphenazine. Either increases toxicity 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)fluphenazine, 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. fluphenazine increases and midodrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.mifepristoneMonitor Closely (1)mifepristone, fluphenazine. QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available.milnacipranMonitor Closely (1)milnacipran, fluphenazine. 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).mirabegronMonitor Closely (1)mirabegron will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.mirtazapineMonitor Closely (1)fluphenazine and mirtazapine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)mirtazapine and fluphenazine both increase QTc interval. Avoid or Use Alternate Drug.mobocertinibSerious - Use Alternative (1)mobocertinib and fluphenazine both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, reduce mobocertinib dose and monitor QTc interval more frequently.modafinilMonitor Closely (1)fluphenazine increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.moexiprilMinor (1)fluphenazine increases effects of moexipril by unspecified interaction mechanism. Minor/Significance Unknown.morphineMonitor Closely (1)morphine and fluphenazine both increase sedation. Use Caution/Monitor.motherwortMonitor Closely (1)fluphenazine and motherwort both increase sedation. Use Caution/Monitor.moxifloxacinSerious - Use Alternative (1)fluphenazine and moxifloxacin both increase QTc interval. Avoid or Use Alternate Drug.moxonidineMonitor Closely (1)fluphenazine and moxonidine both increase sedation. Use Caution/Monitor.nabiloneMonitor Closely (1)fluphenazine and nabilone both increase sedation. Use Caution/Monitor.nalbuphineMonitor Closely (1)nalbuphine and fluphenazine both increase sedation. Use Caution/Monitor.naratriptanMonitor Closely (1)naratriptan, fluphenazine. 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).nilotinibSerious - Use Alternative (1)fluphenazine and nilotinib both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)nilotinib will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.norepinephrineMonitor Closely (2)fluphenazine, 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. fluphenazine increases and norepinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.nortriptylineMonitor Closely (1)fluphenazine and nortriptyline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)fluphenazine and nortriptyline both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)nortriptyline, fluphenazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects. nortriptyline, fluphenazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.octreotideSerious - Use Alternative (1)fluphenazine and octreotide both increase QTc interval. Avoid or Use Alternate Drug.octreotide (Antidote)Serious - Use Alternative (1)fluphenazine and octreotide (Antidote) both increase QTc interval. Avoid or Use Alternate Drug.ofloxacinMonitor Closely (1)fluphenazine and ofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.olanzapineMonitor Closely (3)olanzapine and fluphenazine both increase QTc interval. Use Caution/Monitor. fluphenazine and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. fluphenazine and olanzapine both increase sedation. Use Caution/Monitor.oliceridineMonitor Closely (1)oliceridine, fluphenazine. 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