tcsc1927 Risperidone (hydrochloride)

Risperidone hydrochloride is a serotonin 5-HT₂ receptor blocker and a potent dopamine D₂ receptor antagonist, with K_is of 0.16, 1.4 nM for 5-HT₂ and D₂ receptor, respectively.

IC50 & Target: Ki: 0.16 nM (5-HT₂ receptor); 1.4 nM (dopamine D2 receptor)^[1].

In Vitro: Risperidone is serotonin 5-HT₂ receptor blocker as shown by displacement of radioligand binding (K_i=0.16 nM), activity on isolated tissues (EC₅₀=0.5 nM). Risperidone is also a potent dopamine D₂ receptor antagonist as indicated by displacement of radioligand binding (K_i=1.4 nM), activity in isolated striatal slices (IC₅₀=0.89 nM)^[1]. Risperidone increases the production of IL-10 and MDC as well as the proinflammatory cytokines, such as IL-6, IL-8, and TNF-α, but decreases the production of IP-10 and IL-12^[2].

In Vivo: Long-Evans rats receive daily subcutaneous injections of vehicle or 1 of 2 doses of risperidone (1.0 and 3.0 mg/kg per day) from postnatal Days 14 to 42. Weight gain during development is slightly yet significantly reduced in risperidone-treated rats. In the first 2 experiments, early-life Risperidone administration is associated with increased locomotor activity at 1 week post administration through approximately 9 months of age, independent of changes in weight gain^[2].