Once- and twice-daily nitrendipine in patients with hypertension and noninsulin-dependent diabetes.
One hundred and six patients with uncomplicated mild to moderate essential hypertension received nitrendipine 10 mg twice a day or 20 mg once a day in a double-blind, randomized design. At the end of the dosing interval, supine and standing blood pressures were lowered 6/4 and 6/3 mm Hg respectively with the former regimen, and 2/3 mm Hg with the latter. In 10 patients, blood pressure variability through the dosing interval was not increased by nitrendipine 10 mg twice daily, but in another 10, 20 mg daily increased the variability by 28% compared to placebo. Significantly more patients had adverse effects with 20 mg daily than 10 mg twice daily; and both regimens caused more side effects than placebo. In 20 patients, serum glucose levels did not change significantly during treatment with nitrendipine, but in 10 of those with noninsulin-dependent diabetes, the range of maximum plasma insulin in response to a high-carbohydrate meal was 7 times as great during treatment with nitrendipine as it was during treatment with placebo. Nitrendipine lowers blood pressure when given once or twice daily, but twice-daily administration appears to be better tolerated.