Comparative Pharmacology
Head-to-head clinical analysis: GEODON versus RISPERDAL CONSTA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: GEODON versus RISPERDAL CONSTA.
GEODON vs RISPERDAL CONSTA
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.
Risperidone is an atypical antipsychotic with high affinity for serotonin 5-HT2A and dopamine D2 receptors. It also binds to alpha1-adrenergic, alpha2-adrenergic, and histamine H1 receptors, with low affinity for muscarinic receptors. The combination of 5-HT2A and D2 antagonism is thought to improve negative symptoms and reduce extrapyramidal side effects.
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.
25 mg intramuscular every 2 weeks; may increase to 37.5 mg or 50 mg after 4 weeks if needed.
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.
The terminal elimination half-life of risperidone is approximately 20 hours for CYP2D6 extensive metabolizers and 24 hours for poor metabolizers (accounting for both risperidone and 9-hydroxyrisperidone). The half-life of the active moiety is about 20 hours, allowing for biweekly dosing of the long-acting injection.
Primarily hepatic metabolism via aldehyde oxidase and CYP3A4. Approximately 20% excreted renally as unchanged drug, with the remainder as metabolites (mostly fecal).
Risperidone and its active metabolite 9-hydroxyrisperidone are primarily excreted renally (70%), with 14% excreted in feces. The remainder is eliminated via biliary and metabolic pathways.
Category C
Category C
Atypical Antipsychotic
Atypical Antipsychotic