Prediction of response to antihypertensive therapy with enalapril and nifedipine.

We evaluated the usefulness of an integrated concentration-effect modelling technique in predicting the long-term response to antihypertensive therapy with enalapril and nifedipine. Two groups of essential hypertensives were given monotherapy with 20 mg nifedipine twice a day (n = 14) or 20 mg enalapril once a day (n = 13), and were studied following the administration of the drugs and after at least 6 weeks' treatment. For both drugs the predicted responses (predose and 4 h postdose) were in close agreement with the observed responses. With enalapril the observed and predicted profiles over a 12-h study period were well correlated in all subjects. In contrast, with nifedipine, although there was generally good agreement, the model over-predicted the profile of response in one patient and under-predicted the profile in one patient. Thus, there is evidence that application of concentration-effect analysis is useful in predicting the steady-state antihypertensive effect from the first dose-response to the drug.