DIFFERENTIAL REDUCTION OF MORPHINE-WITHDRAWAL BODY SHAKES BY BUTACLAMOL ENANTIOMERS

Rats withdrawn from continuous morphine infusion showed reliable occurrence of withdrawal body shakes. This sign of narcotic withdrawal was inhibited by the neuroleptic drug, (+) butaclamol. (-) Butaclamol was inactive. (+) Butaclamol activity was not antagonized by naloxone (5 mg/kg). The anti-withdrawal mechanism of (+) butaclamol is discussed in terms of effects on dopamine and narcotic receptors. The butyrophenone neuroleptic, haloperidol, has been used successfully to reduce signs of narcotic withdrawal in laboratory animals (1-4) and human addicts (5). Other neuroleptics of the butyrophenone type also show anti-withdrawal action (6, 7). The mechanism of action of these neuroleptics in blocking narcotic withdrawal is not understood. Butaclamol is a new neuroleptic drug that is available in two enantiomers and only (+) butaclamol possesses neuroleptic activity (8-10). Because of its demonstrated stereo-specificity in producing its pharmacological action, we employed this drug to establish specificity of action of neuroleptics in blocking narcotic withdrawal. © 1978.