Comparative Pharmacology
Head-to-head clinical analysis: QUETIAPINE versus SEROQUEL XR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: QUETIAPINE versus SEROQUEL XR.
Quetiapine vs SEROQUEL XR
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Antagonist at serotonin 5-HT2A, dopamine D2, histamine H1, and adrenergic α1 receptors; weak partial agonist at 5-HT1A and serotonin transporter.
SEROQUEL XR (quetiapine fumarate) is an atypical antipsychotic that acts as an antagonist at multiple neurotransmitter receptors: serotonin 5-HT1A and 5-HT2A, dopamine D1 and D2, histamine H1, and adrenergic α1 and α2 receptors. It also has partial agonist activity at 5-HT1A receptors. The therapeutic efficacy in schizophrenia and bipolar disorder is primarily attributed to dopamine D2 and serotonin 5-HT2A antagonism.
Initial: 25 mg PO BID, titrate to effective range 150-750 mg/day divided BID-TID; schizophrenia: 150-750 mg/day, bipolar disorder: 400-800 mg/day, major depressive disorder (adjunct): 150-300 mg/day at bedtime.
Initial: 300 mg orally once daily; may increase by 300 mg/day every 2-3 days. Target dose: 400-800 mg/day for schizophrenia; 300-600 mg/day for bipolar depression; 400-800 mg/day for acute mania. Maximum: 800 mg/day.
None Documented
None Documented
Clinical Note
moderateQuetiapine + Levofloxacin
"Quetiapine may increase the QTc-prolonging activities of Levofloxacin."
Clinical Note
moderateQuetiapine + Norfloxacin
"Quetiapine may increase the QTc-prolonging activities of Norfloxacin."
Clinical Note
moderateQuetiapine + Gemifloxacin
"Quetiapine may increase the QTc-prolonging activities of Gemifloxacin."
Clinical Note
moderateQuetiapine + Fluticasone propionate
"The risk or severity of adverse effects can be increased when Quetiapine is combined with Fluticasone propionate."
Terminal elimination half-life: ~6-7 hours (parent drug); extended-release: ~7 hours. Clinically, dosing is twice daily for immediate-release; once daily for extended-release.
Terminal elimination half-life: approximately 7 hours (range 6-9 hours) for the extended-release formulation. Clinical context: once-daily dosing achieves steady-state within 2 days.
Renal: 73% (as metabolites), Fecal: 20% (as metabolites), unchanged drug: <1% renal
Primarily hepatic; 70-73% excreted in urine as metabolites (mostly inactive), 20-24% in feces. Less than 1% excreted unchanged in urine.
Category C
Category C
Atypical Antipsychotic
Atypical Antipsychotic