Nicardipine and hydrochlorothiazide in essential hypertension

Nicardipine is an investigational dihydropyridine calcium channel blocking agent. One hundred fifty-one patients with hypertension received either 30 mg nicardipine t.i.d. or 25 mg hydrochlorothiazide b.i.d. in a double-blind, randomized, multicenter trial. After 4 weeks of therapy and at the end of the dosing interval, nicardipine reduced arterial pressure by 10/6 mm Hg and 12/6 mm Hg in the supine and standing positions, respectively (all p < 0.01). In the hydrochlorothiazide group, the reductions were 12/6 mm Hg and 14/6 mm Hg, respectively (all p < 0.01). The maximum reduction in blood pressure of 16/14 mm Hg supine and 20/15 mm Hg standing occurred within 1 hour after administration of nicardipine. The mean reduction in the hydrochlorothiazide group after 1 hour was 14/11 mm Hg supine and 16/12 mm Hg standing. Neither drug affected autonomic reflexes associated with maximum exercise. Nicardipine increased urinary sodium excretion during the 4-hour period after the first dose. Adverse effects of nicardipine were primarily extensions of its vasodilator effect and included flushing, headache, and edema. Clinical Pharmacology and Therapeutics (1989) 45, 429–438; doi:10.1038/clpt.1989.51