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).Serious - Use Alternative (1)fentanyl, fluphenazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.fentanyl intranasalSerious - Use Alternative (1)fentanyl intranasal, fluphenazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.fentanyl transdermalSerious - Use Alternative (1)fentanyl transdermal, fluphenazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.fentanyl transmucosalSerious - Use Alternative (1)fentanyl transmucosal, fluphenazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.fesoterodineMonitor Closely (3)fesoterodine decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. fesoterodine decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor. fluphenazine increases effects of fesoterodine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.fexinidazoleSerious - Use Alternative (1)fexinidazole and fluphenazine both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to block potassium channels or prolong QT interval.fezolinetantContraindicated (1)fluphenazine will increase the level or effect of fezolinetant by affecting hepatic enzyme CYP1A2 metabolism. Contraindicated. Fezolinetant AUC and peak plasma concentration are increased if coadministered with drugs that are weak, moderate, or strong CYP1A2 inhibitorsfingolimodMonitor Closely (1)fingolimod and fluphenazine both increase QTc interval. Use Caution/Monitor.flavoxateMonitor Closely (3)flavoxate decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. flavoxate decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor. fluphenazine increases effects of flavoxate by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.flecainideMonitor Closely (1)fluphenazine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.flibanserinMonitor Closely (1)flibanserin, fluphenazine. affecting hepatic/intestinal enzyme CYP3A4 metabolism. 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).fluconazoleSerious - Use Alternative (1)fluphenazine and fluconazole both increase QTc interval. Avoid or Use Alternate Drug.fluoxetineSerious - Use Alternative (2)fluphenazine and fluoxetine both increase QTc interval. Avoid or Use Alternate Drug. fluoxetine will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.flurazepamMonitor Closely (1)flurazepam and fluphenazine both increase sedation. Use Caution/Monitor.fluvoxamineMonitor Closely (1)fluvoxamine and fluphenazine both increase QTc interval. Use Caution/Monitor.formoterolMonitor Closely (1)fluphenazine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)fluphenazine and formoterol both increase QTc interval. Avoid or Use Alternate Drug.foscarnetMonitor Closely (1)fluphenazine and foscarnet both increase QTc interval. Modify Therapy/Monitor Closely.fosinoprilMinor (1)fluphenazine increases effects of fosinopril by unspecified interaction mechanism. Minor/Significance Unknown.fostemsavirMonitor Closely (1)fluphenazine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir. frovatriptanMonitor Closely (1)frovatriptan, 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).ganaxoloneMonitor Closely (1)fluphenazine and ganaxolone both increase sedation. Use Caution/Monitor.gemifloxacinMonitor Closely (1)gemifloxacin and fluphenazine both increase QTc interval. Use Caution/Monitor.gilteritinibMonitor Closely (1)gilteritinib and fluphenazine both increase QTc interval. Use Caution/Monitor.givosiranSerious - Use Alternative (1)givosiran will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP2D6 substrates with givosiran. If unavoidable, decrease the CYP2D6 substrate dosage in accordance with approved product labeling.glycopyrrolateMonitor Closely (2)fluphenazine increases toxicity of glycopyrrolate by unknown mechanism. Use Caution/Monitor. fluphenazine increases effects of glycopyrrolate by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.glycopyrrolate inhaledMonitor Closely (4)glycopyrrolate inhaled decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. glycopyrrolate inhaled decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor. fluphenazine increases effects of glycopyrrolate inhaled by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. fluphenazine increases toxicity of glycopyrrolate inhaled by unknown mechanism. Use Caution/Monitor.glycopyrronium tosylate topicalMonitor Closely (1)glycopyrronium tosylate topical, fluphenazine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration of glycopyrronium tosylate topical with other anticholinergic medications may result in additive anticholinergic adverse effects.granisetronMonitor Closely (1)granisetron and fluphenazine both increase QTc interval. Use Caution/Monitor.guanfacineMonitor Closely (1)guanfacine, fluphenazine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects; potential delirium.haloperidolMonitor Closely (2)fluphenazine and haloperidol both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. fluphenazine and haloperidol both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)fluphenazine and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)haloperidol will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.henbaneMonitor Closely (3)henbane decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. henbane decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor. fluphenazine increases effects of henbane by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.homatropineMonitor Closely (3)homatropine decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. homatropine decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor. fluphenazine increases effects of homatropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.hydrocodoneSerious - Use Alternative (1)hydrocodone, fluphenazine. 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. 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).hydromorphoneMonitor Closely (1)hydromorphone and fluphenazine both increase sedation. Use Caution/Monitor.hydroxychloroquine sulfateSerious - Use Alternative (1)hydroxychloroquine sulfate and fluphenazine both increase QTc interval. Avoid or Use Alternate Drug.hydroxyzineMonitor Closely (2)hydroxyzine and fluphenazine both increase sedation. Use Caution/Monitor. hydroxyzine and fluphenazine both increase QTc interval. Use Caution/Monitor.hyoscyamineMonitor Closely (3)hyoscyamine decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. hyoscyamine decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor. fluphenazine increases effects of hyoscyamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.hyoscyamine sprayMonitor Closely (3)fluphenazine increases effects of hyoscyamine spray by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. hyoscyamine spray decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. hyoscyamine spray decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor.ibutilideContraindicated (1)fluphenazine and ibutilide both increase QTc interval. Contraindicated.iloperidoneMonitor Closely (3)fluphenazine and iloperidone both increase QTc interval. Modify Therapy/Monitor Closely. fluphenazine and iloperidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. fluphenazine and iloperidone both increase sedation. Use Caution/Monitor.imatinibMinor (1)imatinib will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.imidaprilMinor (1)fluphenazine increases effects of imidapril by unspecified interaction mechanism. Minor/Significance Unknown.imipramineMonitor Closely (1)fluphenazine and imipramine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)fluphenazine and imipramine both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)imipramine, fluphenazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects. imipramine, fluphenazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.incobotulinumtoxinAMonitor Closely (1)fluphenazine, incobotulinumtoxinA. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Use of anticholinergic drugs after administration of botulinum toxin-containing products may potentiate systemic anticholinergic effects.indacaterol, inhaledMonitor Closely (1)indacaterol, inhaled, fluphenazine. QTc interval. Use Caution/Monitor. Drugs that are known to prolong the QTc interval may have an increased the risk of ventricular arrhythmias.indapamideContraindicated (1)fluphenazine and indapamide both increase QTc interval. Contraindicated.insulin degludecMonitor Closely (1)fluphenazine decreases effects of insulin degludec by Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase blood glucose concentrations.insulin degludec/insulin aspartMonitor Closely (1)fluphenazine decreases effects of insulin degludec/insulin aspart by Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase blood glucose concentrations.insulin inhaledMonitor Closely (1)fluphenazine decreases effects of insulin inhaled by Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase blood glucose concentrations.ipratropiumMonitor Closely (3)ipratropium decreases levels of fluphenazine by 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.isofluraneMonitor Closely (1)isoflurane and fluphenazine both increase QTc interval. Use Caution/Monitor.isoproterenolMonitor Closely (2)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. fluphenazine increases and isoproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.itraconazoleMonitor Closely (1)itraconazole and fluphenazine both increase QTc interval. Use Caution/Monitor.ivosidenibSerious - Use Alternative (1)ivosidenib and fluphenazine both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of QTc prolonging drugs with ivosidenib or replace with alternate therapies. If coadministration of a QTc prolonging drug is unavoidable, monitor for increased risk of QTc interval prolongation.ketoconazoleSerious - Use Alternative (1)fluphenazine and ketoconazole both increase QTc interval. Avoid or Use Alternate Drug.ketotifen, ophthalmicMonitor Closely (1)fluphenazine and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.lapatinibMonitor Closely (1)fluphenazine and lapatinib both increase QTc interval. Modify Therapy/Monitor Closely.lasmiditanMonitor Closely (1)lasmiditan, 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.lefamulinSerious - Use Alternative (1)lefamulin and fluphenazine both increase QTc interval. Avoid or Use Alternate Drug.lemborexantMonitor Closely (1)lemborexant, 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.levalbuterolMonitor Closely (1)fluphenazine increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.levodopaSerious - Use Alternative (1)fluphenazine decreases effects of levodopa by pharmacodynamic antagonism. Avoid or Use Alternate Drug.levodopa inhaledSerious - Use Alternative (1)fluphenazine decreases effects of levodopa inhaled by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Phenothiazine/1st generation antipsychotics inhibit dopamine D2 receptors in varying degrees.levofloxacinMonitor Closely (1)fluphenazine and levofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.levoketoconazoleSerious - Use Alternative (1)fluphenazine and levoketoconazole both increase QTc interval. Avoid or Use Alternate Drug.levomilnacipranMonitor Closely (1)levomilnacipran, 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).levorphanolMonitor Closely (1)levorphanol and fluphenazine both increase sedation. Use Caution/Monitor.linezolidMonitor Closely (1)linezolid, fluphenazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly