[Pharmacological studies of an antipschotic agent, penfluridol. (1). The central pharmacological actions]

Neuropharmacological properties of penfluridol (TLP-607) were investigated in experimental animals and were compared with those of haloperidol and chlorpromazine. Locomotor activity of mice significantly decreased at doses of 16-32 mg/kg p.o. Like haloperidol and chlorpromazine, TLP-607 (4-16 mg/kg p.o.) demonstrated catalepsy lasting for 48-72 hr in rats. TLP-607 strongly inhibited apomorphine-induced emesis in dogs and the ED50 was 0.016 mg/kg p.o. This effect lasted for 192 hr when administered 0.04 mg/kg p.o. TLP-607 antagnonized methamphetamine-induced stereotyped behavior in rats, and the ED50 was 1.83 ng/kg p.o. TLP-607 also inhibited conditioned avoidance responses in rats, and the ED50's in the pole climbing and Sidman avoidance methods were 6.73 and 3.4 mg/kg p.o., respectively. TLP-607 neither inhibited motor coordination nor enhanced hexobarbital-induced anesthesia in mice. These results suggest that TLP-607 is a potent and long-acting antipsychotic drug which has less neurotoxic side-effects.