Comparative Pharmacology
Head-to-head clinical analysis: QUETIAPINE FUMARATE versus RISPERDAL CONSTA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: QUETIAPINE FUMARATE versus RISPERDAL CONSTA.
QUETIAPINE FUMARATE vs RISPERDAL CONSTA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Antagonist at serotonin 5-HT2A, dopamine D2, histamine H1, alpha1-adrenergic, and muscarinic M1 receptors. Also partial agonist at serotonin 5-HT1A and dopamine D2 receptors (depending on dose).
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.
Immediate release: 25-100 mg orally twice daily, titrated as needed up to 400-800 mg/day divided twice daily. Extended release: 50-200 mg orally once daily, titrated up to 400-800 mg/day once daily.
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 6-7 hours (quetiapine) and 9-12 hours for the active metabolite norquetiapine; with extended-release formulation, effective half-life is ~7 hours due to slower absorption. Clinical steady-state achieved within 2 days.
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: 73% (20% unchanged, remainder as metabolites); Fecal: 21%; Approximately 5% excreted in feces as unchanged drug.
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 A/B
Category C
Atypical Antipsychotic
Atypical Antipsychotic