Effect of nifedipine in hypertension not controlled by converting enzyme inhibitor and diuretic

Nifedipine, in a slow release preparation, was given at a mean daily dosage of 47 +/- 4 mg to 12 patients with severe hypertension in whom arterial pressure was not satisfactorily controlled (mean blood pressure, 172 +/- 6/111 +/- 4 mmHg) by the association of a converting enzyme inhibitor and a diuretic. Nifedipine administration induced a marked decrease in blood pressure (to 133 +/- 3/85 +/- 3 mmHg), serum potassium and plasma aldosterone. Following adequate control of hypertension and because of severe hypokalaemia in some patients, the diuretic was discontinued in 10 subjects. After 1.7 +/- 0.5 months of treatment by the converting enzyme inhibitor and nifedipine, no change in arterial pressure occurred whilst serum potassium returned to normal in most patients. These results demonstrate that nifedipine may be useful in patients with residual elevation of arterial pressure when treated by converting enzyme inhibitor and diuretic. However, in such patients serum potassium level should be carefully monitored. In addition, our observations suggest that calcium blockers may be an effective alternative to diuretics in patients receiving a converting enzyme inhibitor.