hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).nebivololperphenazine will increase the level or effect of nebivolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.norepinephrineperphenazine increases and norepinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.perphenazine, 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.nortriptylineperphenazine will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.perphenazine and nortriptyline both increase sedation. Use Caution/Monitor.ofloxacinperphenazine and ofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.olanzapineolanzapine and perphenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.olanzapine and perphenazine both increase sedation. Use Caution/Monitor.olanzapine and perphenazine both increase QTc interval. Use Caution/Monitor.oliceridineoliceridine, perphenazine. 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 inhaledperphenazine 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 perphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.onabotulinumtoxinA decreases levels of perphenazine by pharmacodynamic antagonism. Use Caution/Monitor.perphenazine increases effects of onabotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.opium tinctureopium tincture and perphenazine both increase sedation. Use Caution/Monitor.orphenadrineorphenadrine and perphenazine both increase sedation. Use Caution/Monitor.osimertinibosimertinib and perphenazine 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 perphenazine both increase QTc interval. Use Caution/Monitor.oxazepamoxazepam and perphenazine both increase sedation. Use Caution/Monitor.oxybutyninoxybutynin decreases levels of perphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.oxybutynin decreases levels of perphenazine by pharmacodynamic antagonism. Use Caution/Monitor.perphenazine increases effects of oxybutynin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.oxybutynin topicaloxybutynin topical decreases levels of perphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.oxybutynin topical decreases levels of perphenazine by pharmacodynamic antagonism. Use Caution/Monitor.perphenazine increases effects of oxybutynin topical by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.oxybutynin transdermaloxybutynin transdermal decreases levels of perphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.oxybutynin transdermal decreases levels of perphenazine by pharmacodynamic antagonism. Use Caution/Monitor.perphenazine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.oxycodoneperphenazine will increase the level or effect of oxycodone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.oxycodone and perphenazine both increase sedation. Use Caution/Monitor.oxymorphoneperphenazine will increase the level or effect of oxymorphone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.oxymorphone and perphenazine both increase sedation. Use Caution/Monitor.ozanimodozanimod and perphenazine 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.paliperidonepaliperidone and perphenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.perphenazine and paliperidone both increase QTc interval. Modify Therapy/Monitor Closely.paliperidone and perphenazine both increase sedation. Use Caution/Monitor.pancuroniumpancuronium decreases levels of perphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.pancuronium decreases levels of perphenazine by pharmacodynamic antagonism. Use Caution/Monitor.perphenazine increases effects of pancuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.panobinostatpanobinostat will increase the level or effect of perphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Panobinostat can increase the levels and effects of sensitive CYP2D6 substrates or those with a narrow therapeutic index CYP2D6.papaveretumpapaveretum and perphenazine both increase sedation. Use Caution/Monitor.papaverineperphenazine and papaverine both increase sedation. Use Caution/Monitor.paroxetineparoxetine, perphenazine. 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).pasireotideperphenazine and pasireotide both increase QTc interval. Modify Therapy/Monitor Closely.pazopanibperphenazine and pazopanib both increase QTc interval. Use Caution/Monitor.peginterferon alfa 2bpeginterferon alfa 2b, perphenazine. Other (see comment). Use Caution/Monitor. Comment: When patients are administered peginterferon alpha-2b with CYP2D6 substrates, the therapeutic effect of these drugs may be altered. Peginterferon alpha-2b may increase or decrease levels of CYP2D6 substrate.pentazocinepentazocine and perphenazine both increase sedation. Use Caution/Monitor.pentobarbitalpentobarbital and perphenazine both increase sedation. Use Caution/Monitor.phendimetrazineperphenazine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.perphenazine, phendimetrazine. 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.phenelzinephenelzine, perphenazine. 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).phenobarbitalphenobarbital and perphenazine both increase sedation. Use Caution/Monitor.phentermineperphenazine increases and phentermine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.perphenazine, phentermine. 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.phenylephrineperphenazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.perphenazine, phenylephrine. 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.phenylephrine POperphenazine increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .perphenazine, phenylephrine PO. 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.pholcodineperphenazine and pholcodine both increase sedation. Use Caution/Monitor.pimozideperphenazine and pimozide both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.perphenazine and pimozide both increase sedation. Use Caution/Monitor.pirbuterolperphenazine increases and pirbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.porfimerperphenazine, porfimer. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Enhanced photosensitivity.posaconazoleperphenazine and posaconazole both increase QTc interval. Modify Therapy/Monitor Closely.pralidoximepralidoxime decreases levels of perphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.pralidoxime decreases levels of perphenazine by pharmacodynamic antagonism. Use Caution/Monitor.perphenazine increases effects of pralidoxime by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.primaquineprimaquine and perphenazine both increase QTc interval. Use Caution/Monitor.primidoneprimidone and perphenazine both increase sedation. Use Caution/Monitor.procarbazineprocarbazine, perphenazine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Excessive sedation.procarbazine, perphenazine. 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).prochlorperazineperphenazine and prochlorperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.perphenazine and prochlorperazine both increase sedation. Use Caution/Monitor.promethazineperphenazine and promethazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.promethazine and perphenazine both increase sedation. Use Caution/Monitor.promethazine, perphenazine. 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).propafenoneperphenazine will increase the level or effect of propafenone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.propafenone will increase the level or effect of perphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.propanthelinepropantheline decreases levels of perphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.propantheline decreases levels of perphenazine by pharmacodynamic antagonism. Use Caution/Monitor.perphenazine increases effects of propantheline by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.propofolpropofol and perphenazine both increase sedation. Use Caution/Monitor.propranololperphenazine will increase the level or effect of propranolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.propylhexedrineperphenazine increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.perphenazine, propylhexedrine. 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.protriptylineperphenazine and protriptyline both increase sedation. Use Caution/Monitor.pseudoephedrineperphenazine, pseudoephedrine. Mechanism: unknown. Use Caution/Monitor. Consider avoiding use of pseudoephedrine in patients receiving phenothiazines (especially thioridazine) due to the potential risk of cardiac arrhythmia or sudden death. Monitor for evidence of ventricular arrhythmias during concomitant use.quazepamquazepam and perphenazine both increase sedation. Use Caution/Monitor.quetiapineperphenazine and quetiapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.perphenazine and quetiapine both increase sedation. Use Caution/Monitor.quinidinequinidine will increase the level or effect of perphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.quinineperphenazine and quinine both increase QTc interval. Use Caution/Monitor.ramelteonperphenazine and ramelteon both increase sedation. Use Caution/Monitor.ranolazineperphenazine and ranolazine both increase QTc interval. Modify Therapy/Monitor Closely.rapacuroniumrapacuronium decreases levels of perphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.rapacuronium decreases levels of perphenazine by pharmacodynamic antagonism. Use Caution/Monitor.perphenazine increases effects of rapacuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.remimazolamremimazolam, perphenazine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely. Coadministration may result in profound sedation, respiratory depression, coma, and/or death. Continuously monitor vital signs during sedation and recovery period if coadministered. Carefully titrate remimazolam dose if administered with opioid analgesics and/or sedative/hypnotics.rimabotulinumtoxinBperphenazine, rimabotulinumtoxinB. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Anticholinergics may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.risperidoneperphenazine and risperidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.perphenazine and risperidone both increase QTc interval. Modify Therapy/Monitor Closely.perphenazine and risperidone both increase sedation. Use Caution/Monitor.rizatriptanrizatriptan, perphenazine. 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).rocuroniumrocuronium decreases levels of perphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.rocuronium decreases levels of perphenazine by pharmacodynamic antagonism. Use Caution/Monitor.perphenazine increases effects of rocuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.rolapitantrolapitant will increase the level or effect of perphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Rolapitant may increase plasma concentrations of CYP2D6 substrates for at least 28 days following rolapitant administration.romidepsinperphenazine and romidepsin both increase QTc interval. Modify Therapy/Monitor Closely.salmeterolperphenazine increases and salmeterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.scopolaminescopolamine decreases levels of perphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.scopolamine decreases levels of perphenazine by pharmacodynamic antagonism. Use Caution/Monitor.perphenazine increases effects of scopolamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.scullcapperphenazine and scullcap both increase sedation. Use Caution/Monitor.secobarbitalsecobarbital and perphenazine both increase sedation. Use Caution/Monitor.selegilineselegiline, perphenazine. 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).selpercatinibselpercatinib increases toxicity of perphenazine by QTc interval. Use Caution/Monitor.serdexmethylphenidate/dexmethylphenidateperphenazine, serdexmethylphenidate/dexmethylphenidate. 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.sertralinesertraline and perphenazine both increase QTc interval. Use Caution/Monitor.sevofluranesevoflurane and perphenazine