Effect of chlorpromazine or sulpiride and alcohol on psychomotor skills related to driving

Abstract

A double-blind cross-over trial was conducted with 20 healthy paid volunteers for the evaluation of the subacute effects of chlorpromazine (CPZ) and sulpiride, in oral doses used for anxious outpatients, on psychomotor skills related to driving. Psychomotor performance was measured on the 7th and 14th days of treatment at 30, 90 and 150 min after the intake of 0.5 g/kg of an alcoholic or placebo drink. After the neuroleptics alone, reaction and coordination skills, but not attention, were slightly impaired, CPZ differing significantly from the placebo on the 14th day. Both drugs interacted additively with alcohol. The combined administration of CPZ and alcohol led to inaccuracy, a slowing of reactions and impaired proprioception and coordination. The combination of sulpiride and alcohol increased the error rate in the choice reaction test and impaired coordination in the coordination test driven at a free speed. It is concluded that the psychomotor decrement that occurs after 2 weeks of treatment with small doses of CPZ may effect the ability to control a motor vehicle. The concurrent administration of alcohol during treatment with CPZ or sulpiride may cause some extra risk in traffic or occupational life.