Comparative effect of three antihistaminics and ethanol on mental and motor performance

The effect of three antihistaminics, alone and with ethanol, on mental and motor performance has been measured. Alcohol consistently effected a significant impairment of both mental and motor performance. No significant mental impairment was observed when the antihistaminic drugs were given alone, nor was the effect of ethanol potentiated by them significantly. When motor performance was measured, none of the antihistaminics alone produced significant effects. In the presence of ethanol, the action of diphenhydramine was potentiated in two tests. The depressant property of the antihistaminics studied was much more apparent to the subjects than that of alcohol, and, yet, significant impairment was observed only with alcohol.