inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.ipratropium decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor.fluphenazine increases effects of ipratropium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.isofluraneisoflurane and fluphenazine both increase QTc interval. Use Caution/Monitor.isoproterenolfluphenazine increases and isoproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.fluphenazine, isoproterenol. 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.itraconazoleitraconazole and fluphenazine both increase QTc interval. Use Caution/Monitor.ketotifen, ophthalmicfluphenazine and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.lapatinibfluphenazine and lapatinib both increase QTc interval. Modify Therapy/Monitor Closely.lasmiditanlasmiditan, fluphenazine. Either increases effects of the other by sedation. Use Caution/Monitor. Coadministration of lasmiditan and other CNS depressant drugs, including alcohol have not been evaluated in clinical studies. Lasmiditan may cause sedation, as well as other cognitive and/or neuropsychiatric adverse reactions.lemborexantlemborexant, fluphenazine. Either increases effects of the other by sedation. Modify Therapy/Monitor Closely. Dosage adjustment may be necessary if lemborexant is coadministered with other CNS depressants because of potentially additive effects.levalbuterolfluphenazine increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.levofloxacinfluphenazine and levofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.levomilnacipranlevomilnacipran, 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).levorphanollevorphanol and fluphenazine both increase sedation. Use Caution/Monitor.linezolidlinezolid, 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).liraglutidefluphenazine, liraglutide. Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase or decrease glucose levels, monitor therapy closely when these agents are concurrently administered.lisdexamfetaminefluphenazine increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.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.lithiumlithium, 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.lofepraminefluphenazine and lofepramine both increase sedation. Use Caution/Monitor.lofexidinefluphenazine and lofexidine both increase sedation. Use Caution/Monitor.loprazolamloprazolam and fluphenazine both increase sedation. Use Caution/Monitor.lorazepamlorazepam and fluphenazine both increase sedation. Use Caution/Monitor.lorcaserinlorcaserin 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).lormetazepamlormetazepam and fluphenazine both increase sedation. Use Caution/Monitor.loxapinefluphenazine 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 inhaledfluphenazine 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.lumefantrinelumefantrine will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.lurasidonelurasidone, 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.maprotilinefluphenazine and maprotiline both increase sedation. Use Caution/Monitor.marijuanafluphenazine and marijuana both increase sedation. Use Caution/Monitor.meclizinemeclizine 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.melatoninfluphenazine and melatonin both increase sedation. Use Caution/Monitor.meperidinemeperidine and fluphenazine both increase sedation. Use Caution/Monitor.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).meprobamatefluphenazine and meprobamate both increase sedation. Use Caution/Monitor.metaproterenolfluphenazine increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.metaxalonemetaxalone and fluphenazine both increase sedation. Use Caution/Monitor.metforminfluphenazine 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.methadonefluphenazine and methadone both increase QTc interval. Modify Therapy/Monitor Closely.methadone and fluphenazine both increase sedation. Use Caution/Monitor.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).methamphetaminefluphenazine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.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.methocarbamolmethocarbamol and fluphenazine both increase sedation. Use Caution/Monitor.methoxsalenmethoxsalen, fluphenazine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive photosensitizing effects.methscopolaminemethscopolamine 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.methylenedioxymethamphetaminefluphenazine increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.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.methylergonovinemethylergonovine, 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).methylphenidatefluphenazine, 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.metoclopramidefluphenazine and metoclopramide both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.midazolammidazolam and fluphenazine both increase sedation. Use Caution/Monitor.midazolam intranasalmidazolam 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.midodrinefluphenazine increases and midodrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.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.mifepristonemifepristone, fluphenazine. QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available.milnacipranmilnacipran, 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).mirabegronmirabegron will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.mirtazapinefluphenazine and mirtazapine both increase sedation. Use Caution/Monitor.modafinilfluphenazine increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.morphinemorphine and fluphenazine both increase sedation. Use Caution/Monitor.motherwortfluphenazine and motherwort both increase sedation. Use Caution/Monitor.moxonidinefluphenazine and moxonidine both increase sedation. Use Caution/Monitor.nabilonefluphenazine and nabilone both increase sedation. Use Caution/Monitor.nalbuphinenalbuphine and fluphenazine both increase sedation. Use Caution/Monitor.naratriptannaratriptan, 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).norepinephrinefluphenazine increases and norepinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.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.nortriptylinefluphenazine and nortriptyline both increase sedation. Use Caution/Monitor.ofloxacinfluphenazine and ofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.olanzapinefluphenazine 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.olanzapine and fluphenazine both increase QTc interval. Use Caution/Monitor.oliceridineoliceridine, 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 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 inhaledfluphenazine 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 arrhythmiasonabotulinumtoxinAonabotulinumtoxinA decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.onabotulinumtoxinA decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor.fluphenazine increases effects of onabotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.opium tinctureopium tincture and fluphenazine both increase sedation. Use Caution/Monitor.orphenadrineorphenadrine and fluphenazine both increase sedation. Use Caution/Monitor.osilodrostatosilodrostat and fluphenazine both increase QTc interval. Use Caution/Monitor.osimertinibosimertinib and fluphenazine both increase QTc interval. Use Caution/Monitor. Conduct periodic monitoring with ECGs and electrolytes in patients taking drugs known to prolong the QTc interval.oxaliplatinoxaliplatin and fluphenazine both increase QTc interval. Use Caution/Monitor.oxazepamoxazepam and fluphenazine both increase sedation. Use Caution/Monitor.oxybutyninoxybutynin decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.oxybutynin decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor.fluphenazine increases effects of oxybutynin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.oxybutynin topicaloxybutynin topical decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.oxybutynin topical decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor.fluphenazine increases effects of oxybutynin topical by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.oxybutynin transdermaloxybutynin transdermal decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.oxybutynin transdermal decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor.fluphenazine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.oxycodoneoxycodone and fluphenazine both increase sedation. Use Caution/Monitor.oxymorphoneoxymorphone and fluphenazine both increase sedation. Use Caution/Monitor.ozanimodozanimod and fluphenazine 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.paliperidonefluphenazine and paliperidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.fluphenazine and paliperidone both increase QTc interval. Modify Therapy/Monitor Closely.fluphenazine and paliperidone both increase sedation. Use Caution/Monitor.pancuroniumpancuronium decreases levels