The pharmacokinetics of ramipril in a group of ten elderly patients with essential hypertension.

This open, general practice study looked at the pharmacokinetics of ramipril over a period of 1 year in elderly (greater than 65 years) hypertensive patients. Ten patients with a diastolic blood pressure between 95 and 125 mm Hg were treated with 5 mg of ramipril daily for 4 weeks, followed by an additional 11 months of treatment in which the dose was titrated against the blood pressure. Pharmacokinetic data were collected at baseline, 4 weeks, and 1 year. Mean peak concentrations of ramiprilat (the active diacid) were 11.5 ng/ml acutely, 18.5 ng/ml at 1 month, and 31.3 ng/ml at 1 year, and these were all statistically significantly different. Mean half-lives of ramiprilat were 5.5 h acutely, 5.2 h at 1 month, and 4.6 h at 1 year, and these were not statistically significantly different. Mean areas under the curve excluding the component for saturable binding were 106.8 ng/h/ml acutely, 115.7 ng/h/ml at 1 month, and 248 ng/h/ml at 1 year; the latter was statistically significantly different from the earlier readings. There is no evidence from this study that the pharmacokinetics change in any clinically relevant way.