The relationship between serum enalaprilat concentration and the hypotensive effect in man.

The relationship between serum concentrations of the angiotensin converting enzyme inhibitor, enalaprilat, and its antihypertensive action was investigated using integrated pharmacokinetic-dynamic modelling techniques. The model was parameterized in terms of slope "m", describing the sensitivity to the fall of blood pressure, and an intercept term "i". A linear pharmacodynamic model: E = m. ce(t) + i, adequately characterized the concentration-effect relationship in most of the young (aged 22-30 years) and elderly normotensive subjects (aged 65-73 years). However, no age-related differences were seen, indicating that angiotensin II vasoconstrictor action is unaltered by senescence.