Comparative Pharmacology
Head-to-head clinical analysis: PALIPERIDONE PALMITATE versus RISPERDAL CONSTA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PALIPERIDONE PALMITATE versus RISPERDAL CONSTA.
PALIPERIDONE PALMITATE vs RISPERDAL CONSTA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Paliperidone is an atypical antipsychotic with high affinity for serotonin 5-HT2A and dopamine D2 receptors. It also blocks alpha-2 adrenergic and H1 histaminergic 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.
Paliperidone palmitate is administered intramuscularly. Initial dose: 150 mg eq. on day 1 and 100 mg eq. on day 8, both in the deltoid muscle. Maintenance dose: 75 mg eq. monthly (range 25–150 mg eq.) administered in the deltoid or gluteal muscle.
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: 25-49 days (mean ~30 days) for IM injection; allows monthly dosing
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: 80% as unchanged drug and metabolites; fecal: 11%
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