Nitrendipine versus hydrochlorothiazide in hypertensive patients over 70 years of age.

The effects of nitrendipine and hydrochlorothiazide were studied in hypertensive elderly patients. Blood pressure was reduced (p less than 0.01) by both nitrendipine (13/10 +/- 4/3 mm Hg [n = 15], mean +/- SE) and hydrochlorothiazide (25/11 +/- 4/2 mm Hg [n = 16]). After hydrochlorothiazide, plasma glucose, uric acid, and renin activity increased and plasma potassium levels decreased. Edema and flushing were the main adverse reactions during nitrendipine. The response of blood pressure and heart rate to head-up tilt were not significantly different under both treatments. However, the effects of both drugs on diastolic blood pressure and norepinephrine responses to head-up tilt differed significantly. We conclude that, in the elderly, hydrochlorothiazide lowers systolic blood pressure more effectively than nitrendipine. However, nitrendipine does not have any of the potentially harmful metabolic side effects that were found during hydrochlorothiazide therapy. The clinical significance of a lower vasoreactivity during nitrendipine, as was found with the head-up tilt test, has to be established.