The relation of age to the acute effects of ethanol on acetanilide disposition.

The activity of the major drug-metabolizing enzymes, the mono-oxygenases, can be inhibited by an acute dose of ethanol. We set out to determine whether age has any relation to the degree of inhibition produced by ethanol, using acetanilide as a model substrate. Eight healthy young subjects (mean age 26 years) and eight healthy elderly subjects (mean age 72 years) were studied on two occasions, once receiving acetanilide alone and once acetanilide with 75 ml vodka (30 g ethanol). The clearance of acetanilide was significantly lower (p less than 0.05) in the elderly subjects at 27 +/- 3 l/h compared to 38 +/- 2 l/h in young subjects. No age-related differences in peak blood ethanol concentrations or ethanol elimination rates were noted. After ethanol, acetanilide clearance fell 18% to 31 +/- 3 l/h in young subjects (p = 0.05) and by 15% to 23 +/- 2 l/h in elderly subjects (p = 0.08). This suggests that the elderly do not suffer greater impairment of drug oxidation after acute ethanol ingestion than do the young.