RWJ-51204 binds to receptors with Ki ranging from 0.2 to 0.6 nM in the cerebral cortex, cerebellum, or medulla-spinal cord.[1]

RWJ-51204 is effective in the conflict test in monkeys (ED50 of approximately 0.5 mg/kg p.o.). RWJ-51204 is orally active in anxiolytic efficacy tests. RWJ-51204 effectively impairs rotarod performance in rats (ED50 = 0.12 mg/kg), and all rats given RWJ-51204 orally at 30 mg/kg exhibit sedation, reduced skeletal muscle tone, and impairment of rotarod performance. [1]