THE EFFECTS OF HALOPERIDOL AND CHLORPROMAZINE ON AMPHETAMINE METABOLISM AND AMPHETAMINE STEREOTYPE BEHAVIOR IN THE RAT

haloperidol and chiorpromazineon amphetamine metabolism and amphetamine stereotype behavior in the rat. J. Pharmacol. Exp. Ther. 174: 428-433, 1970.Chlorpromazinehas been used for the treatment of severe amphetamine toxicity. The present investigation compares the effects of chiorpromasine and haloperidol on amphetamine metabolism and the ability of each to block amphetamine stereotype behavior. In rats treated with chlorpromazine (15 mg/kg) or haloperidol (10 mg/kg) 30 minutes prior to the administration of H5-ampheta mine, there was a slowing of the disappearance of H'-amphetamine from the brain. The half-life of the labeled amine increased to 140 minutes after chiorpromazine and to 69 miii utes after haloperidol from a control value of 52 minutes in saline-pretreated control rats. After pretreatment with chiorpromazine (15 mg/kg) or haloperidol (10 mg/kg) only 29% and 80 % (respectively) of the administered 115-amphetamine was metabolized in 3 hours by the whole rat as comparedto 93%of the administered dose in control animals. Haloperidol (0.5 mg/kg) completely blocked amphetamine stereotype behavior whereas chiorpromazune in doses of 1 and 5 mg/kg only partially blocked this effect. Haloperidol in a dose which blocked amphetaminestereotype behavior had no inhibitory effect on amphetamine metab