Bifeprunox is an atypical antipsychotic.1 It is a dopamine D2 receptor partial agonist and an agonist of the serotonin (5-HT) receptor subtype 5-HT1A (Kis = 2.2 and 9.3 nM, respectively).2,3 Bifeprunox inhibits apomorphine-induced climbing behavior in mice (ED50 = 0.1 mg/kg) and the conditioned avoidance response in rats (ED50 = 0.8 mg/kg).3 It decreases basal prepulse inhibition of the acoustic startle response in rats by 42% when administered at a dose of 10 mg/kg.2

|1. Wadenberg, M.-L.G. Bifeprunox: A novel antipsychotic agent with partial agonist properties at dopamine D2 and serotonin 5-HT1A receptors. Future Neurol. 2(2), 153-165 (2007).|2. Auclair, A.L., Galinier, A., Besnard, J., et al. Putative antipsychotics with pronounced agonism at serotonin 5-HT1A and partial agonist activity at dopamine D2 receptors disrupt basal PPI of the startle reflex in rats. Psychopharmacol. (Berl). 193(1), 45-54 (2007).|3. Feenstra, R.W., de Moes, J., Hofma, J.J., et al. New 1-aryl-4-(biarylmethylene)piperazines as potential atypical antipsychotics sharing dopamine D2-receptor and serotonin 5-HT1A-receptor affinities. Bioorg. Med. Chem. Lett. 11(17), 2345-2349 (2001).