A Comparison of the Disposition of Single Oral Doses of Amlodipine in Young and Elderly Subjects

The potential use of calcium antagonists in the treatment of hypertension and ischemic heart disease in elderly patients creates a requirement for pharmacokinetic information that is specific for that age group. This study describes the pharmacokinetics of amlodipine after single oral doses of 5 mg in 16 elderly subjects, mean age 72 years, age range 65-85 years. The principal findings were that the mean elimination half-life was 48 h and that peak plasma drug concentrations were not observed until 7 h after dosing. In comparison with data obtained from a group of young subjects, mean age 26 years, there were significant differences in pharmacokinetics. The terminal elimination half-life of 48 h in the elderly was significantly longer than that of 35 h in the young subjects and there was a correspondingly greater area under the curve in the elderly, by approximately 50%. These findings are consistent with an age-related reduction in drug clearance.