decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor. quetiapine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.darunavirMonitor Closely (1)darunavir will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.dasatinibMonitor Closely (2)dasatinib will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. quetiapine, dasatinib. 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.deferasiroxMonitor Closely (1)deferasirox will decrease the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.degarelixMonitor Closely (1)quetiapine, degarelix. 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.desfluraneMonitor Closely (1)desflurane and quetiapine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)desflurane and quetiapine both increase QTc interval. Avoid or Use Alternate Drug.desipramineMonitor Closely (2)quetiapine and desipramine both increase sedation. Use Caution/Monitor. quetiapine, desipramine. 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.deutetrabenazineMonitor Closely (3)quetiapine and deutetrabenazine both increase sedation. Use Caution/Monitor. quetiapine and deutetrabenazine both increase QTc interval. Use Caution/Monitor. At the maximum recommended dose, deutetrabenazine does not prolong QT interval to a clinically relevant extent. Certain circumstances may increase risk of torsade de pointes and/or sudden death in association with drugs that prolong the QTc interval (eg, bradycardia, hypokalemia or hypomagnesemia, coadministration with other drugs that prolong QTc interval, presence of congenital QT prolongation). quetiapine and deutetrabenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Modify Therapy/Monitor Closely. The risk for parkinsonism, neuroleptic malignant syndrome, and akathisia may be increased by concomitant use of deutetrabenazine and dopamine antagonists or antipsychotics.dexamethasoneMonitor Closely (1)dexamethasone will decrease the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.dexchlorpheniramineMonitor Closely (1)dexchlorpheniramine and quetiapine both increase sedation. Use Caution/Monitor.dexfenfluramineMonitor Closely (1)quetiapine increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.dexmedetomidineMonitor Closely (1)dexmedetomidine and quetiapine both increase sedation. Use Caution/Monitor.dexmethylphenidateMonitor Closely (1)quetiapine increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.dextroamphetamineMonitor Closely (1)quetiapine increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.dextromethorphanMonitor Closely (1)dextromethorphan, 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).dextromoramideMonitor Closely (1)dextromoramide and quetiapine both increase sedation. Use Caution/Monitor.DHEA, herbalMonitor Closely (1)DHEA, herbal will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.diamorphineMonitor Closely (1)diamorphine and quetiapine both increase sedation. Use Caution/Monitor.diazepamMonitor Closely (1)diazepam and quetiapine both increase sedation. Use Caution/Monitor.dichlorphenamideMonitor Closely (1)dichlorphenamide and quetiapine both decrease serum potassium. Use Caution/Monitor.dicyclomineMonitor Closely (3)dicyclomine decreases levels of quetiapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. dicyclomine decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor. quetiapine increases effects of dicyclomine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.diethylpropionMonitor Closely (1)quetiapine increases and diethylpropion decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.difelikefalinMonitor Closely (1)difelikefalin and quetiapine both increase sedation. Use Caution/Monitor.difenoxin hclMonitor Closely (1)difenoxin hcl and quetiapine both increase sedation. Use Caution/Monitor.dihydroergotamineMonitor Closely (1)dihydroergotamine, 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).diltiazemMonitor Closely (1)diltiazem will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.dimenhydrinateMonitor Closely (1)dimenhydrinate and quetiapine both increase sedation. Use Caution/Monitor.diphenhydramineMonitor Closely (4)diphenhydramine decreases levels of quetiapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. diphenhydramine decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor. quetiapine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. diphenhydramine and quetiapine both increase sedation. Use Caution/Monitor.diphenoxylate hclMonitor Closely (1)diphenoxylate hcl and quetiapine both increase sedation. Use Caution/Monitor.dipipanoneMonitor Closely (1)dipipanone and quetiapine both increase sedation. Use Caution/Monitor.disopyramideMonitor Closely (1)quetiapine, disopyramide. 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.dobutamineMonitor Closely (1)quetiapine increases and dobutamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.dofetilideMonitor Closely (2)quetiapine, dofetilide. 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. dofetilide increases toxicity of quetiapine by QTc interval. Use Caution/Monitor.dolasetronMonitor Closely (1)quetiapine, dolasetron. 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.donepezilSerious - Use Alternative (1)donepezil and quetiapine both increase QTc interval. Avoid or Use Alternate Drug.donepezil transdermalMonitor Closely (1)quetiapine, donepezil transdermal. Either decreases effects of the other by pharmacodynamic antagonism. Use Caution/Monitor.dopamineMonitor Closely (1)quetiapine increases and dopamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)quetiapine decreases effects of dopamine by pharmacodynamic antagonism. Contraindicated.dopexamineMonitor Closely (1)quetiapine increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.dosulepinMonitor Closely (1)quetiapine and dosulepin both increase sedation. Use Caution/Monitor.doxepinMonitor Closely (2)quetiapine and doxepin both increase sedation. Use Caution/Monitor. doxepin and quetiapine both increase QTc interval. Use Caution/Monitor.doxylamineMonitor Closely (1)doxylamine and quetiapine both increase sedation. Use Caution/Monitor.dronedaroneMonitor Closely (2)dronedarone will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. quetiapine, dronedarone. 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.droperidolMonitor Closely (3)droperidol and quetiapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. droperidol and quetiapine both increase sedation. Use Caution/Monitor. quetiapine, droperidol. 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.duvelisibMonitor Closely (1)duvelisib will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with duvelisib increases AUC of a sensitive CYP3A4 substrate which may increase the risk of toxicities of these drugs. Consider reducing the dose of the sensitive CYP3A4 substrate and monitor for signs of toxicities of the coadministered sensitive CYP3A substrate.efavirenzMonitor Closely (1)efavirenz will decrease the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)efavirenz and quetiapine both increase QTc interval. Avoid or Use Alternate Drug.elagolixMonitor Closely (1)elagolix decreases levels of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.eletriptanMonitor Closely (1)eletriptan, 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).eliglustatSerious - Use Alternative (1)eliglustat and quetiapine both increase QTc interval. Avoid or Use Alternate Drug.elvitegravir/cobicistat/emtricitabine/tenofovir DFSerious - Use Alternative (1)elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with quetiapine. If coadministration is necessary, reduce quetiapine dose to one-sixth of the current dose.encorafenibMonitor Closely (1)encorafenib, quetiapine. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.Serious - Use Alternative (1)encorafenib and quetiapine both increase QTc interval. Avoid or Use Alternate Drug. Encorafenib is associated with dose-dependent QTc interval prolongation. Avoid with drugs known to prolong QT interval.entrectinibSerious - Use Alternative (1)quetiapine and entrectinib both increase QTc interval. Avoid or Use Alternate Drug.enzalutamideSerious - Use Alternative (1)enzalutamide will decrease the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.ephedrineMonitor Closely (1)quetiapine increases and ephedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.epinephrineMonitor Closely (1)quetiapine increases and epinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.epinephrine racemicMonitor Closely (1)quetiapine increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.ergoloid mesylatesMonitor Closely (1)ergoloid mesylates, 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).ergotamineMonitor Closely (1)ergotamine, 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).eribulinSerious - Use Alternative (1)eribulin and quetiapine both increase QTc interval. Avoid or Use Alternate Drug.erythromycin baseMonitor Closely (1)quetiapine, erythromycin base. 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.Serious - Use Alternative (1)erythromycin base will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.erythromycin ethylsuccinateMonitor Closely (1)quetiapine, erythromycin ethylsuccinate. 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.Serious - Use Alternative (1)erythromycin ethylsuccinate will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.erythromycin lactobionateMonitor Closely (1)quetiapine, erythromycin lactobionate. 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.Serious - Use Alternative (1)erythromycin lactobionate will increase the