Efficacy and tolerability of nisoldipine coat-core formulation in the treatment of essential hypertension: The South African Multicenter ANCHOR Study. Ambulatory Nisoldipine Coat-Core Hypertension Outpatient Response (ANCHOR) Investigators.
A double-blind, placebo-controlled, multicenter trial was undertaken to assess the antihypertensive efficacy and tolerability of a controlled-release (Coat-Core [CC] tablet) formulation of the second-generation dihydropyridine calcium channel antagonist, nisoldipine. Of the 208 patients with mild-to-moderate essential hypertension, two were excluded from the main efficacy analysis, and the rest randomized into one of four treatment groups, to receive either placebo, or nisoldipine CC at doses of 10, 20, or 30 mg once daily for 6 weeks, following a 4-week placebo run-in period. Blood pressure measurements (supine, standing, diastolic, and systolic) were taken at trough plasma levels, 24 h after previous dosing at 2-week intervals throughout the study. Adverse events and laboratory parameters (plasma lipid and glucose levels, and thyroid function) were monitored. All three doses of nisoldipine CC lowered blood pressure, as compared with placebo, 24 h after dosing. At endpoint (after 6 weeks) mean changes in supine blood pressure from baseline were (systolic/diastolic) 0.9/-2.3, -8.0/-5.5, -16.9/-9.0, and -15.0/-10.3 mm Hg for the groups assigned to placebo and nisoldipine CC 10, 20, and 30 mg, respectively. The response rates were 35%, 47%, and 63% for nisoldipine CC 10, 20, and 30 mg, respectively. Twenty-four-hour ambulatory blood pressure monitoring showed that nisoldipine CC effectively controlled blood pressure throughout the dosing interval. No change in heart rate was seen for all three doses of nisoldipine CC over the 24-h dosing interval. Nisoldipine CC was at least as effective in black patients as in whites. Generally adverse events were not increased, except for peripheral edema, with rates of 7% in placebo, and 6%, 9%, and 19%, respectively, in those receiving nisoldipine CC 10, 20, or 30 mg daily. There were no clinically significant changes in blood lipids, blood glucose, or thyroid function. In conclusion, once-daily nisoldipine CC at doses of 10 to 30 mg was an effective and well tolerated antihypertensive agent, providing 24-h control of blood pressure without any increase in heart rate.