Comparative Pharmacology
Head-to-head clinical analysis: QUETIAPINE FUMARATE versus ZYPREXA ZYDIS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: QUETIAPINE FUMARATE versus ZYPREXA ZYDIS.
QUETIAPINE FUMARATE vs ZYPREXA ZYDIS
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Antagonist at serotonin 5-HT2A, dopamine D2, histamine H1, alpha1-adrenergic, and muscarinic M1 receptors. Also partial agonist at serotonin 5-HT1A and dopamine D2 receptors (depending on dose).
Olanzapine is an atypical antipsychotic with high affinity for serotonin 5-HT2A and 5-HT2C receptors, dopamine D1-D4 receptors, muscarinic M1-M5 receptors, histamine H1 receptors, and alpha1-adrenergic receptors. Antagonism at D2 and 5-HT2A receptors is primarily responsible for its antipsychotic effects.
Immediate release: 25-100 mg orally twice daily, titrated as needed up to 400-800 mg/day divided twice daily. Extended release: 50-200 mg orally once daily, titrated up to 400-800 mg/day once daily.
10 mg orally once daily; range 5-20 mg once daily. Initial dose 5-10 mg, titrate by 5 mg weekly. Maximum 20 mg/day. Orally disintegrating tablet.
None Documented
None Documented
Terminal elimination half-life is approximately 6-7 hours (quetiapine) and 9-12 hours for the active metabolite norquetiapine; with extended-release formulation, effective half-life is ~7 hours due to slower absorption. Clinical steady-state achieved within 2 days.
Terminal elimination half-life: ~30 hours (range 21–54 hours) in healthy adults; prolonged in elderly (mean 51.8 h) and hepatic impairment.
Renal: 73% (20% unchanged, remainder as metabolites); Fecal: 21%; Approximately 5% excreted in feces as unchanged drug.
Renal: ~57% (as metabolites); Fecal: ~30% (as metabolites); Unchanged olanzapine in urine <7%.
Category A/B
Category C
Atypical Antipsychotic
Atypical Antipsychotic