Article: PDF OnlyLettieri J.; Krol, G.; Yen, S.; Ryan, J.; Jain, A.; McMahon, F. G.; Burkholder, D.; Birkett, J. P.Journal of Cardiovascular Pharmacology: 1987 - p S142-S147 Free Abstract Summary This study was designed to compare the pharmacokinetics of nitrendipine in young and old healthy volunteers. Single 20 mg oral doses of nitrendipine were given to 12 elderly and 8 young subjects. Plasma and urine samples were collected after dosing and assayed for nitrendipine and metabolites by capillary gas chromatography. The older subjects were found to have significantly higher plasma concentrations of nitrendipine, with an approximately threefold increase in mean C-max and an almost fourfold increase in mean A UC, compared with the younger subjects. There were no significant differences in T-max or t12 between the two groups, although both these parameters were slightly greater in the older subjects. Plasma concentrations of metabolites as well as the cumulative urinary excretion of metabolites, were also higher in the elderly. The plasma profiles of metabolites in a young and an old subject showed distinct differences in the kinetics of the metabolites. The older subject had a more gradual rise and decline in plasma metabolite concentrations. The findings appear to be most consistent with a diminished metabolic capacity in elderly subjects. The possibility that there may be plasma concentrations of nitrendipine that are higher than expected should be considered when using this drug in elderly patients. © Lippincott-Raven Publishers.