The effect of aging on the distribution and elimination of ethanol was studied in a group of 50 healthy subjects ranging in age from 21 to 81 yr (mean, 53.3). Ethanol was administered in a continuous 1-hr infusion at a mean rate of 375 mg/m2 body surface area/min (equivalent to a mean dose of 0.57 gm/kg body weight). Serial blood samples for the determination of ethanol concentration were obtained at 15- to 30-min intervals for up to 4 hr post infusion. Ethanol elimination and distribution were evaluated with the aid of a two-compartment model. Rates of ethanol elimination were not affected by age. Peak ethanol concentration in blood water at the end of the infusion period was correlated with age (r = 0.55, p < 0.001). Lean body mass and total volume of distribution of the ethanol were negatively correlated with age. The smaller volume of distribution, in association with the decreased lean body, mass, most likely explains the higher peak ethanol concentration found in the blood after administration of an ethanol dose on the basis of surface area in the old as compared with the young subjects. This study demonstrates that age-related changes in body composition are important factors in the study of ethanol metabolism and its pharmacologic effects.
ASJC Scopus subject areas
- Pharmacology (medical)