An assessment of the pharmacokinetics and pharmacodynamics of single doses of amlodipine in elderly normotensives.

This study characterizes the single dose pharmacokinetic characteristics of the dihydropyridine calcium antagonist drug amlodipine in a group of 16 elderly subjects, aged 65 to 86 years (8 M:8 F). The most notable pharmacokinetic features were a prolonged terminal elimination half life of 48 +/- 16 hours and a delayed tmax of 7.3 +/- 1.3 hours. Consistent with the time to achieve peak plasma drug concentrations, there was a modest but significant reduction in blood pressure at 6-8 hours after dosing. Comparison of these results with those of published data for young subjects indicate not only a greater degree of intersubject variability but also a longer half life in the elderly, suggestive of reduced drug clearance, which may lead to higher plasma drug concentrations particularly at steady state.