Table 1.
Pharmacodynamics9 | |
Serotonin 5-HT2A, dopamine D2, histaminergic H1, and adrenergic alpha-1 and alpha-2 antagonist Increasing degrees of D2-receptor occupation with increasing doses of LAR injection Little or no affinity for cholinergic muscarinic or beta-1 and beta-2 adrenergic receptors. |
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Pharmacokinetics10 | |
Repeated administration every 2 weeks achieves steady-state plasma levels after the fourth injection Linearpharmacokinetics Intramuscular and oral preperations are bioequvelant but LAR is associated with lower steady-state peak concentrations and less fluctiations in plasma levels compared with oral treatment. |
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Metabolism and elimination11 | |
Metabolized by cytochrome P-450 (CYP) isoenzyme 2D6 to 9-hydroxyrisperidone The half-life of LAR is 3–6 days because of the extended-release profile rather than the metabolic half-life (N-dealkylation is an alternative pathway) LAR is completely eliminated from the body after 6–7 weeks. |