Comparative Pharmacology
Head-to-head clinical analysis: RISPERIDONE versus ZYPREXA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: RISPERIDONE versus ZYPREXA.
RISPERIDONE vs ZYPREXA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Risperidone is an atypical antipsychotic that antagonizes dopamine D2 receptors and serotonin 5-HT2A receptors. It also has moderate affinity for alpha1-adrenergic and H1-histaminergic receptors, and low affinity for muscarinic receptors.
Olanzapine is an atypical antipsychotic that antagonizes dopamine D2 and serotonin 5-HT2A receptors, with higher affinity for 5-HT2A than D2. It also blocks histamine H1, alpha-1 adrenergic, and muscarinic M1 receptors.
Initial 2 mg orally once daily, titrated to target dose of 4-6 mg orally once daily (or divided twice daily); maximum 16 mg/day. Alternatively, long-acting IM injection: 25 mg IM every 2 weeks.
5-10 mg orally once daily; may increase by 5 mg/day at intervals of at least 1 week; maximum 20 mg/day.
None Documented
None Documented
Clinical Note
moderateRisperidone + Fluticasone propionate
"The risk or severity of adverse effects can be increased when Risperidone is combined with Fluticasone propionate."
Clinical Note
moderateRisperidone + Methylphenidate
"The risk or severity of adverse effects can be increased when Risperidone is combined with Methylphenidate."
Clinical Note
moderateRisperidone + Quinagolide
"The therapeutic efficacy of Quinagolide can be decreased when used in combination with Risperidone."
Clinical Note
moderateRisperidone: 3 hours (CYP2D6 extensive metabolizers), 20 hours (poor metabolizers); active metabolite 9-hydroxyrisperidone: 21-30 hours; steady-state reached in 5-6 days
Terminal elimination half-life ~30 hours (range 21–54 h) in adults, allowing once-daily dosing; steady-state reached in ~5–7 days. Half-life prolonged in elderly, females, and hepatic impairment.
Renal (70% as metabolites, 14% as parent drug) and fecal (14%)
Primarily hepatic metabolism via CYP1A2 and CYP2D6; ~7% excreted unchanged in urine, ~57% in urine as metabolites, ~30% in feces (mostly metabolites).
Category A/B
Category C
Atypical Antipsychotic
Atypical Antipsychotic
Risperidone + Cyclosporine
"The metabolism of Cyclosporine can be decreased when combined with Risperidone."