Comparative Pharmacology
Head-to-head clinical analysis: RISPERDAL CONSTA versus SEROQUEL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: RISPERDAL CONSTA versus SEROQUEL.
RISPERDAL CONSTA vs SEROQUEL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
Antagonist at dopamine D2 and serotonin 5-HT2A receptors; also blocks histamine H1 and adrenergic α1 receptors.
25 mg intramuscular every 2 weeks; may increase to 37.5 mg or 50 mg after 4 weeks if needed.
Initial: 25 mg twice daily; titrate by 25-50 mg twice daily on day 2 and 3 to target 300-400 mg daily in 2-3 divided doses. Maintenance: 400-800 mg daily. Maximum: 800 mg daily.
None Documented
None Documented
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.
Terminal elimination half-life approximately 7 hours for quetiapine; for metabolite N-desalkylquetiapine (norquetiapine), approximately 12 hours. Steady-state reached within 2 days.
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.
Primarily hepatic metabolism; <1% excreted unchanged renally. Metabolites excreted in urine (73%) and feces (20%).
Category C
Category C
Atypical Antipsychotic
Atypical Antipsychotic