of ventricular arrhythmiasolopatadine intranasalSerious - Use Alternative (1)quetiapine 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. ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC)Serious - Use Alternative (1)ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC) will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Consider alternative anti-HCV therapy to avoid increases in quetiapine exposures; if coadministration necessary, reduce quetiapine dose to 1/6th of current dose and monitor for quetiapine associated adverse reactions; refer to quetiapine prescribing information for recommendations on adverse reaction monitoring onabotulinumtoxinAMonitor Closely (3)onabotulinumtoxinA decreases levels of quetiapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. onabotulinumtoxinA decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor. quetiapine increases effects of onabotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.ondansetronSerious - Use Alternative (1)quetiapine 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 quetiapine both increase sedation. Use Caution/Monitor.orphenadrineMonitor Closely (1)orphenadrine and quetiapine both increase sedation. Use Caution/Monitor.osilodrostatMonitor Closely (1)osilodrostat and quetiapine both increase QTc interval. Use Caution/Monitor.osimertinibMonitor Closely (1)osimertinib and quetiapine 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 quetiapine 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 quetiapine both increase QTc interval. Avoid or Use Alternate Drug.oxazepamMonitor Closely (1)oxazepam and quetiapine both increase sedation. Use Caution/Monitor.oxcarbazepineMonitor Closely (1)oxcarbazepine will decrease the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.oxybutyninMonitor Closely (3)oxybutynin decreases levels of quetiapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. oxybutynin decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor. quetiapine increases effects of oxybutynin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.oxybutynin topicalMonitor Closely (3)oxybutynin topical decreases levels of quetiapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. oxybutynin topical decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor. quetiapine increases effects of oxybutynin topical by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.oxybutynin transdermalMonitor Closely (3)oxybutynin transdermal decreases levels of quetiapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. oxybutynin transdermal decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor. quetiapine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.oxycodoneMonitor Closely (1)oxycodone and quetiapine both increase sedation. Use Caution/Monitor.oxymorphoneMonitor Closely (1)oxymorphone and quetiapine both increase sedation. Use Caution/Monitor.ozanimodMonitor Closely (1)ozanimod and quetiapine 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)paliperidone and quetiapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. paliperidone and quetiapine both increase sedation. Use Caution/Monitor. quetiapine, paliperidone. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval. Postmarketing cases show QT prolongation with overdose in patients with concomitant illness or with drugs known to cause electrolyte imbalance or prolong QT.pancuroniumMonitor Closely (3)pancuronium decreases levels of quetiapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. pancuronium decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor. quetiapine increases effects of pancuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.panobinostatSerious - Use Alternative (1)quetiapine 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 quetiapine both increase sedation. Use Caution/Monitor.papaverineMonitor Closely (1)quetiapine and papaverine both increase sedation. Use Caution/Monitor.paroxetineMonitor Closely (1)paroxetine, quetiapine. 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).pasireotideMonitor Closely (1)quetiapine and pasireotide both increase QTc interval. Modify Therapy/Monitor Closely.pazopanibMonitor Closely (1)quetiapine, pazopanib. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval. Postmarketing cases show QT prolongation with overdose in patients with concomitant illness or with drugs known to cause electrolyte imbalance or prolong QT.pentamidineMonitor Closely (1)quetiapine, pentamidine. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval. Postmarketing cases show QT prolongation with overdose in patients with concomitant illness or with drugs known to cause electrolyte imbalance or prolong QT.pentazocineMonitor Closely (1)pentazocine and quetiapine both increase sedation. Use Caution/Monitor.pentobarbitalMonitor Closely (2)pentobarbital will decrease the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. pentobarbital and quetiapine both increase sedation. Use Caution/Monitor.perphenazineMonitor Closely (2)perphenazine 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.phendimetrazineMonitor Closely (1)quetiapine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.phenelzineMonitor Closely (1)phenelzine, quetiapine. 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).phenobarbitalMonitor Closely (2)phenobarbital will decrease the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. phenobarbital and quetiapine both increase sedation. Use Caution/Monitor.phentermineMonitor Closely (1)quetiapine increases and phentermine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.phenylephrineMonitor Closely (1)quetiapine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.phenylephrine POMonitor Closely (1)quetiapine increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .phenytoinMonitor Closely (1)phenytoin will decrease the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increased doses of quetiapine may be required to maintain control of psychotic symptoms in patients receiving quetiapine and phenytoin. Caution should be taken if phenytoin is withdrawn from therapy or replaced with a non-inducing anticonvulsant.pholcodineMonitor Closely (1)quetiapine and pholcodine both increase sedation. Use Caution/Monitor.pimavanserinSerious - Use Alternative (1)pimavanserin and quetiapine both increase QTc interval. Avoid or Use Alternate Drug. Coadministration may increase the risk of QT prolongation and cardiac arrhythmia.pimozideMonitor Closely (3)pimozide and quetiapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. pimozide and quetiapine both increase sedation. Use Caution/Monitor. quetiapine, pimozide. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval. Postmarketing cases show QT prolongation with overdose in patients with concomitant illness or with drugs known to cause electrolyte imbalance or prolong QT.pioglitazoneMonitor Closely (1)quetiapine, pioglitazone. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.pirbuterolMonitor Closely (1)quetiapine increases and pirbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.pitolisantSerious - Use Alternative (1)quetiapine and pitolisant both increase QTc interval. Avoid or Use Alternate Drug.posaconazoleMonitor Closely (2)posaconazole will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. quetiapine, posaconazole. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval. Postmarketing cases show QT prolongation with overdose in patients with concomitant illness or with drugs known to cause electrolyte imbalance or prolong QT.pralidoximeMonitor Closely (3)pralidoxime decreases levels of quetiapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. pralidoxime decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor. quetiapine increases effects of pralidoxime by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.pramipexoleSerious - Use Alternative (1)quetiapine decreases effects of pramipexole by pharmacodynamic antagonism. Contraindicated.pramlintideMonitor Closely (1)quetiapine, pramlintide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.prednisoneMonitor Closely (1)prednisone will decrease the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.primaquineSerious - Use Alternative (1)primaquine and quetiapine both increase QTc interval. Avoid or Use Alternate Drug.primidoneMonitor Closely (2)primidone will decrease the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. primidone and quetiapine both increase sedation. Use Caution/Monitor.procainamideMonitor Closely (1)quetiapine, procainamide. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval. Postmarketing cases show QT prolongation with overdose in patients with concomitant illness or with drugs known to cause electrolyte imbalance or prolong QT.procarbazineMonitor Closely (1)procarbazine, quetiapine. 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).prochlorperazineMonitor Closely (2)prochlorperazine and quetiapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. prochlorperazine and quetiapine both increase sedation. Use Caution/Monitor.promethazineMonitor Closely (3)promethazine, quetiapine. 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). promethazine and quetiapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. promethazine and quetiapine both increase sedation. Use Caution/Monitor.propafenoneMonitor Closely (1)quetiapine, propafenone. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval. Postmarketing cases show QT prolongation with overdose in patients with concomitant illness or with drugs known to cause electrolyte imbalance or prolong QT.propanthelineMonitor Closely (3)propantheline decreases levels of quetiapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. propantheline decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor. quetiapine increases effects of propantheline by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.propofolMonitor Closely (1)propofol and quetiapine both increase sedation. Use Caution/Monitor.propylhexedrineMonitor Closely (1)quetiapine increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.protriptylineMonitor Closely (2)quetiapine and protriptyline both increase sedation. Use Caution/Monitor. quetiapine, protriptyline. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval. Postmarketing cases show QT prolongation with overdose in patients with concomitant illness or with drugs known to cause electrolyte imbalance or prolong QT.quazepamMonitor Closely (1)quazepam and quetiapine both increase sedation. Use Caution/Monitor.quinidineMonitor Closely (1)quetiapine, quinidine. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval. Postmarketing cases show QT prolongation with overdose in patients with concomitant illness or with drugs known to cause electrolyte imbalance or prolong QT.quinineMonitor Closely (1)quetiapine, quinine. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval.