Efficacy and tolerance of indapamide sustained release 1.5 mg on 24-h blood pressure in essential hypertension

A new 1.5 mg sustained-release (SR) formulations of indapamide has been dev eloped in accordance with the international guidelines recommending low dos es of antihypertensive agents. In order to evaluate its antihypertensive ef fect over 24 h and its benefit in terms of the efficacy/tolerance ratio, th e results of two European double-blind randomized studies, conducted in pat ients with essential moderate hypertension, are reviewed. Antihypertensive efficacy was assessed using clinic blood pressure (BP) measurements at trou gh, 24 h after dosing, (primary criteria) and ambulatory BP monitoring; the main safety criterion was the percentage of patients with serum potassium <3.4 mmol.l-(1). The results of the dose-ranging study established the anti hypertensive efficacy of 1.5 mg of indapamide SR. The equivalence study con firmed the equivalent antihypertensive effect, within the predefined equiva lence interval for diastolic blood pressure of +/- 5 mmHg, between two form ulations of indapamide, the SR at 1.5 mg.day(-1) and the immediate release (IR) at 2.5 mg.day(-1). This effect, observed after 2-3 months of treatment , was long-term and maintained in patients followed over 12 months. Toleran ce data showed no effects of indapamide on carbohydrate and lipid metabolis ms, a slight increase in the uric acid level, and 50% fewer patients with s erum potassium <3.4 mmol.l(-1) with the SR than with the IR formulation. Po oled data showed that the new formulation of indapamide decreases BP over 2 4 h, with a trough to peak ratio meeting the FDA standard requirements and improves the efficacy/tolerance ratio of indapamide in essential hypertensi on.