Comparative Pharmacology
Head-to-head clinical analysis: INVEGA versus RISPERDAL CONSTA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: INVEGA versus RISPERDAL CONSTA.
INVEGA vs RISPERDAL CONSTA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Paliperidone is the major active metabolite of risperidone. It is a benzisoxazole derivative antipsychotic with high affinity for serotonin 5-HT2A and dopamine D2 receptors. It also acts as an antagonist at α1 and α2 adrenergic receptors and H1 histaminergic receptors. It has no affinity for muscarinic 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.
Oral: 6 mg once daily; may increase to 9 mg/day if needed. IM (extended-release): 234 mg on day 1, 156 mg on day 8, then 117 mg monthly; adjust within range 39-234 mg per month.
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 23-29 hours for oral administration (paliperidone extended-release). Once-daily dosing achieves steady-state within 4-5 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.
Primarily renal: 59-80% of dose excreted unchanged in urine (as parent drug and metabolites). Fecal: ~20-30%. Biliary elimination is minimal.
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