Comparative Pharmacology
Head-to-head clinical analysis: GEODON versus ZYPREXA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: GEODON versus ZYPREXA.
GEODON vs ZYPREXA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Ziprasidone is an atypical antipsychotic with high affinity for dopamine D2 and serotonin 5-HT2A receptors; it also antagonizes 5-HT2C, 5-HT1D, alpha1-adrenergic, and histamine H1 receptors, and moderately inhibits serotonin and norepinephrine reuptake.
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.
20 mg orally twice daily with food; may titrate to 40-80 mg orally twice daily; maximum 80 mg orally twice daily. For acute treatment, IM 10-20 mg as needed up to 40 mg/day.
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
Terminal elimination half-life is approximately 7 hours (range 5-10 hours) for oral ziprasidone; after intramuscular administration, half-life is about 2-5 hours. This short half-life may require twice-daily dosing for oral therapy.
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.
Primarily hepatic metabolism via aldehyde oxidase and CYP3A4. Approximately 20% excreted renally as unchanged drug, with the remainder as metabolites (mostly fecal).
Primarily hepatic metabolism via CYP1A2 and CYP2D6; ~7% excreted unchanged in urine, ~57% in urine as metabolites, ~30% in feces (mostly metabolites).
Category C
Category C
Atypical Antipsychotic
Atypical Antipsychotic