Antihypertensive therapy with nitrendipine: comparison with hydrochlorothiazide and propranolol

The calcium channel blockers are being used increasingly to treat essential hypertension. Nitrendipine is a second-generation dihydropyridine derivative that, though not yet approved in the United States, has been extensively evaluated both there and abroad. This report concerns two multicenter trials in which nitrendipine was compared to hydrochlorothiazide and propranolol. In the first study, which included 305 patients over 50 years of age with off-treatment sitting diastolic blood pressures of 95-114 mm Hg, nitrendipine 10 mg b.i.d. was compared to hydrochlorothiazide 50 mg q.d. The mean blood pressure readings were reduced from 157/101 to 142/89 mm Hg with nitrendipine and from 157/101 to 139/88 mm Hg with hydrochlorothiazide. The goal diastolic blood pressure of less than 90 mm Hg was achieved in 69% of the nitrendipine-treated patients and 51% of the hydrochlorothiazide group (p less than 0.001). There were no differences in the incidence or severity of side effects with the two agents, but hydrochlorothiazide produced more frequent laboratory abnormalities. In the second trial, nitrendipine 5-20 mg b.i.d., was compared with propranolol 40-120 mg b.i.d. in 300 patients with the same entry blood pressure criteria. The reduction in blood pressure with nitrendipine, from 156/101 to 138/87 mm Hg, was slightly but significantly greater than that on propranolol, which was from 157/101 to 142/90 mm Hg. Side effects and dropouts were somewhat more frequent in the propranolol group. These studies indicate that nitrendipine is an effective and well-tolerated agent for hypertension monotherapy, and that it compares favorably with the other classes of drugs commonly used as initial therapy.