Effects of Chlorpromazine and Alcohol on Coordination and Judgment

This study was designed to test the belief that simultaneous use of tranquilizing drugs and alcoholic drinks has a particularly bad effect on neuromuscular coordination and interferes with safety in automobile driving. A battery of tests was applied to 24 volunteer subjects under four experimental conditions achieved with combinations of alcohol and chlorpromazine, alcohol and placebo tablet, placebo drink and chlorpromazine, and placebo drink and placebo tablet. The effect of alcohol and chlorpromazine taken together significantly impaired the performance of the subjects. The more complex tasks were most affected, and the subjects became aware of dulness, lethargy, and poor coordination. Chlorpromazine alone impaired performance, but the impairment caused by alcohol with chlorpromazine was significantly greater. Patients obliged to take chlorpromazine should be warned that the use of alcohol greatly increases the dangers of operating complex machinery, including automobiles.