The effect of aging on the pharmacokinetics of nizatidine.

: A single oral dose of 300 mg of nizatidine was administered to two groups of volunteers: a first group of 12 young healthy subjects and a second group of 12 elderly patients, in order to compare the pharmacokinetic parameters and to verify a possible influence of the age on nizatidine's kinetics. Blood samples were collected periodically and plasma concentrations of the drug were determined by a specific HPLC method. The results evidenced differences among the pharmacokinetic parameters of the two groups: the mean of Cmax was higher in the elderly than in the young (3.28 mg/ml against 2.23 mg/ml), the peak time was prolonged in the elderly (2.1 h against 1.00 h) and the AUC values were higher too (12.17 in the elderly and 7.99 in the young). Only the elimination half-life t1/2 was slightly higher in the elderly (1.8 h against 1.7 h in the young).