Digoxin pharmacokinetics was studied in 40 virtually healthy subjects aged 60-89 years and 10 subjects aged 20-29 years injected with a single dose (0.5 mg) of digoxin. The pharmacokinetic data were interpreted in terms of a two-compartmental model. The constant of digoxin transfer rate from the peripheral compartment to the central one appreciably increased, whereas the elimination constant and the magnitude of the total clearance was decreased with aging. The values of the apparent volume of the drug distribution in the central compartment, as well as those of the stationary and kinetic volumes of distribution got reduced. In elderly and senile subjects, the pharmacokinetic curve area increased. The half-life of digoxin in young, elderly and senile subjects was equal to 51, 54 and 57 h, respectively.