Comparative Pharmacology
Head-to-head clinical analysis: RISPERDAL versus RISPERDAL CONSTA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: RISPERDAL versus RISPERDAL CONSTA.
RISPERDAL vs RISPERDAL CONSTA
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.
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.
2-8 mg orally once daily or divided twice daily; maximum 16 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
20 hours (parent drug), 23 hours (active metabolite 9-hydroxyrisperidone). Steady state reached in 5-6 days. Extended in elderly and hepatic/renal impairment.
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.
Renal: 70% (30% as unchanged drug, 40% as metabolites), Fecal/Biliary: 14%
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