Comparative Pharmacology
Head-to-head clinical analysis: RISPERDAL versus ZYPREXA ZYDIS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: RISPERDAL versus ZYPREXA ZYDIS.
RISPERDAL vs ZYPREXA ZYDIS
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Risperidone is a benzisoxazole atypical antipsychotic that antagonizes dopamine D2 and serotonin 5-HT2A receptors. It also blocks alpha1-adrenergic, alpha2-adrenergic, and histamine H1 receptors.
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.
2-8 mg orally once daily or divided twice daily; maximum 16 mg/day
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
20 hours (parent drug), 23 hours (active metabolite 9-hydroxyrisperidone). Steady state reached in 5-6 days. Extended in elderly and hepatic/renal impairment.
Terminal elimination half-life: ~30 hours (range 21–54 hours) in healthy adults; prolonged in elderly (mean 51.8 h) and hepatic impairment.
Renal: 70% (30% as unchanged drug, 40% as metabolites), Fecal/Biliary: 14%
Renal: ~57% (as metabolites); Fecal: ~30% (as metabolites); Unchanged olanzapine in urine <7%.
Category C
Category C
Atypical Antipsychotic
Atypical Antipsychotic