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.thiothixeneMonitor Closely (3)quetiapine and thiothixene both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. quetiapine and thiothixene both increase sedation. Use Caution/Monitor. quetiapine, thiothixene. 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.tiotropiumMonitor Closely (3)tiotropium decreases levels of quetiapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. tiotropium decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor. quetiapine increases effects of tiotropium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.tipranavirMonitor Closely (1)tipranavir will decrease the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration may increase quetiapine systemic exposure; more frequent monitoring of the clinical response to quetiapine as well as potential adverse events is recommendedtolazamideMonitor Closely (1)quetiapine, tolazamide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.tolbutamideMonitor Closely (1)quetiapine, tolbutamide. Other (see comment). Use Caution/Monitor. Comment: Atypical antipsychotics have been associated with hyperglycemia that may alter blood glucose control; monitor glucose levels closely.tolterodineMonitor Closely (3)tolterodine decreases levels of quetiapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. tolterodine decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor. quetiapine increases effects of tolterodine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.topiramateMonitor Closely (2)topiramate will decrease the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. quetiapine and topiramate both increase sedation. Modify Therapy/Monitor Closely.toremifeneMonitor Closely (1)quetiapine, toremifene. 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.tramadolMonitor Closely (1)tramadol and quetiapine both increase sedation. Use Caution/Monitor.tranylcypromineMonitor Closely (1)tranylcypromine, 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).trazodoneMonitor Closely (1)quetiapine and trazodone both increase sedation. Use Caution/Monitor.triazolamMonitor Closely (1)triazolam and quetiapine both increase sedation. Use Caution/Monitor.triclabendazoleMonitor Closely (1)triclabendazole and quetiapine both increase QTc interval. Use Caution/Monitor.triclofosMonitor Closely (1)triclofos and quetiapine both increase sedation. Use Caution/Monitor.trifluoperazineMonitor Closely (2)quetiapine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. quetiapine and trifluoperazine both increase sedation. Use Caution/Monitor.trihexyphenidylMonitor Closely (1)quetiapine increases effects of trihexyphenidyl by pharmacodynamic synergism. Use Caution/Monitor. Potential for additive anticholinergic effects.trimipramineMonitor Closely (2)quetiapine and trimipramine both increase sedation. Use Caution/Monitor. quetiapine, trimipramine. 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.triprolidineMonitor Closely (1)triprolidine and quetiapine both increase sedation. Use Caution/Monitor.triptorelinSerious - Use Alternative (1)triptorelin increases toxicity of quetiapine by QTc interval. Avoid or Use Alternate Drug. Increases risk of torsades de pointes.trospium chlorideMonitor Closely (3)trospium chloride decreases levels of quetiapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. trospium chloride decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor. quetiapine increases effects of trospium chloride by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.tucatinibSerious - Use Alternative (1)tucatinib will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.umeclidinium bromide/vilanterol inhaledSerious - Use Alternative (1)quetiapine increases toxicity of umeclidinium bromide/vilanterol inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.vandetanibMonitor Closely (1)quetiapine, vandetanib. 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.vardenafilMonitor Closely (1)quetiapine, vardenafil. 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.vecuroniumMonitor Closely (3)vecuronium decreases levels of quetiapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. vecuronium decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor. quetiapine increases effects of vecuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.vemurafenibSerious - Use Alternative (1)vemurafenib and quetiapine both increase QTc interval. Avoid or Use Alternate Drug. Concomitant use of vemurafenib with drugs that prolong QT interval is not recommended.venlafaxineMonitor Closely (1)venlafaxine, 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).verapamilMonitor Closely (1)verapamil will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.vilanterol/fluticasone furoate inhaledSerious - Use Alternative (1)quetiapine increases toxicity of vilanterol/fluticasone furoate inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.vilazodoneMonitor Closely (1)vilazodone, 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).voclosporinMonitor Closely (1)voclosporin, quetiapine. Either increases effects of the other by QTc interval. Use Caution/Monitor.voriconazoleMonitor Closely (2)voriconazole will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. quetiapine, voriconazole. 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.vorinostatMonitor Closely (1)quetiapine, vorinostat. 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.voxelotorSerious - Use Alternative (1)voxelotor will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.xylometazolineMonitor Closely (1)quetiapine increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.yohimbineMonitor Closely (1)quetiapine increases and yohimbine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.zafirlukastMonitor Closely (1)zafirlukast will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ziconotideMonitor Closely (1)quetiapine and ziconotide both increase sedation. Use Caution/Monitor.ziprasidoneMonitor Closely (3)quetiapine and ziprasidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. quetiapine and ziprasidone both increase sedation. Use Caution/Monitor. quetiapine, ziprasidone. 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.zolmitriptanMonitor Closely (1)zolmitriptan, 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).zotepineMonitor Closely (2)quetiapine and zotepine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor. quetiapine and zotepine both increase sedation. Use Caution/Monitor. >10% Dizziness (1-18%) Fatigue (3-14%) Extrapyramidal symptoms (1-13%) Increased diastolic blood pressure (41%) Increased triglycerides (8-22%) Increased total cholesterol (7-18%) Increased appetite (2-12%) Constipation (6-11%) Dry mouth (9-44%) Headache (7-21) Somnolence (18-57%) 1-10% Abdominal pain (4-7%; dose related) Dyspepsia (2-7%; dose related Tremor (2-8%) Back pain (3-5%) Postural hypotension (2-7%) Tachycardia (1-6%) Pharyngitis (4-6%) Rhinitis (3-4%) Rash (4%) Blurred vision (1-4%) Arthralgia (1-4%) Myalgia (2%) Neck pain (2%) Dyskinesia (4%) Neutropenia (2%) Hemorrhage (1%) < 1% Priapism Cardiomyopathy, myocarditis QTc prolongation Night mares Pancreatitis Rhabdomyolysis Palpitation Leukocytosis Epistaxis Exfoliative dermatitis Postmarketing Reports Drug reaction with eosinophilia and systemic symptoms (DRESS), falls, nocturnal enuresis, retrograde amnesia, syndrome of inappropriate antidiuretic hormone secretion (SIADH), Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), decreased platelet count, serious liver reactions (including hepatitis, liver necrosis, and hepatic failure), agranulocytosis, intestinal obstruction, ileus, colon ischemia, urinary retention, sleep apnea, acute generalized exanthematous pustulosis (AGEP), confusional state, and cutaneous vasculitis Black Box Warnings Not approved for dementia-related psychosis; elderly patients with dementia-related psychosis who are treated with antipsychotic drugs are at increased risk of death, as shown in short-term controlled trials; deaths in these trials appeared to be either cardiovascular (eg, heart failure, sudden death) or infectious (eg, pneumonia) in nature Increased risk of suicidal thinking and behavior in children, adolescents, and young adults taking antidepressants for major depressive disorder and other psychiatric disorders; prescriptions should be written for smallest therapeutically effective quantity, and caregivers should monitor and report to healthcare professionals incidence of suicidality and associated behaviors Not approved for children <10 yearsContraindications Documented hypersensitivity Cautions Use with caution in cardiovascular and cerebrovascular disease May worsen hypotensive conditions Use with caution in breast cancer and history of seizure Increased risk of hyperglycemia and diabetes; in some cases, hyperglycemia concomitant with use of atypical antipsychotics has been associated with ketoacidosis, hyperosmolar coma, or death; monitor blood glucose of high-risk patients for symptoms of hyperglycemia including polydipsia, polyuria, polyphagia, and weakness; monitor glucose regularly in patients with diabetes or at risk for diabetes Increased incidence of cerebrovascular adverse effects, including stroke and TIAs, in elderly with dementia (not approved for the treatment of patients with dementia-related psychosis); see Black Box Warnings Neuroleptic malignant syndrome (NMS) reported with use Tardive dyskinesia possible after discontinuance Clinical worsening of depression and suicide ideation may occur despite treatment Hyperlipidemia may occur; appropriate clinical monitoring is recommended, including fasting blood lipid testing at the beginning of, and periodically, during treatment Weight gain may occur; monitoring of weight recommended Cataract may occur; monitor Increased blood pressure in children and adolescents reported; monitor blood pressure at the beginning of, and periodically during treatment Leukopenia, neutropenia, and agranulocytosis may occur; perform a complete blood count (CBC) during first few months of therapy; in such patients, consider discontinuation of therapy at first sign of clinically significant decline in WBC in absence of other causative factors Can elevate prolactin levels, and elevation can persist during