SB 243213 is an orally active, selective and high-affinity 5-HT2C receptor antagonist with a pKi of 9.37 and a pKb of 9.8 for human 5-HT2C receptor. SB 243213 shows greater than a 100-fold selectivity over a wide range of neurotransmitter receptors, enzymes and ion channels. SB 243213 has improved anxiolytic profile and has the potential for schizophrenia and motor disorders[1].

SB 243213 shows little affinity (pKi<6) for cloned human 5-HT1A, 5-HT1B, 5-HT1E, 5- HT1F and 5-HT7 receptors. It shows weak affinity (pKi<6.5) for the cloned human 5-HT1D and D3 receptors and moderate affinity (pKi=6.7) for the cloned human D2 receptor[1].

SB 243213 (0.1-10 mg/kg, p.o. 1 h pre-test) dose-dependently and significantly increases the amount of time rats spent in social interaction over 15 min under brightly lit conditions and in an unfamiliar test box[1]. SB 243213 (0.3 mg/kg; p.o.; 1 h pre-test) significantly increases time spent in social interaction[1]. Animal Model: Male Sprague-Dawley experimentally naive rats (220-300 g)[1]

[1]. Wood MD, et al. SB-243213; a selective 5-HT2C receptor inverse agonist with improved anxiolytic profile: lack of tolerance and withdrawal anxiety. Neuropharmacology. 2001 Aug;41(2):186-99.