The effect of alcohol intake on the disposition of diphenhydramine in man.

The disposition of diphenhydramine (DPHA) and its principal metabolites was investigated in two subjects after i.v. and oral dosing. Based on these parameters the results of a multiple oral dose regimen were predicted and compared to the results obtained in these volunteers. During one dose interval of the multiple oral dose regimen, the volunteers indulged in social drinking. Comparison of this interval with a control period showed no differences in disposition. Alcohol therefore, would appear to have no effect on the disposition of DPHA.