The pharmacology of a new potent, long acting neuroleptic, piflutixol

Piflutixol, 6-fluoro-9-[3-(4-(2-hydroxyethyl)piperidino)propylidene]-2-trifluoromethyl-thioxanthene, has been shown to have pronounced neuroleptic properties. It is a very potent inhibitor of methylphenidate-induced stereotypies in mice, amphetamine and apomorphine-induced stereotypies in rats, apomorphine-induced stereotypies and vomiting in dogs. Furthermore piflutixol causes cataleptic reaction in small doses and inhibits conditioned avoidance reaction in rats. The compound is equally potent orally and parenterally and has a prolonged effect. Piflutixol has up to the present proved to be the most potent inhibitor of dopamine-stimulated adenylate cyclase in rat striatum in vitro. Piflutixol has a stron sedative effect (inhibition of spontaneous motor activity, induction of ptosis and potentiation of barbiturate anaesthesia) and in addition inhibits reticular arousal reaction in very low doses. Thus piflutixol constitutes a unique combination of potent anti-stereotyped activity with potent sedative effects. This means that piflutixol may prove to be a low-dose basic neuroleptic with long duration of action.