Clinical Efficacy and Safety of Lower-Dose Indapamide Therapy in the Treatment of Patients with Mild to Moderate Hypertension.

Abstract

Previous clinical studies with indapamide, an indoline antihypertensive drug with diuretic and vasodilating activities, have shown a dose relationship associated with potassium loss. Two placebo-controlled, randomized, double-blind, parallel clinical studies were, therefore, done to evaluate the safety and efficacy of a low dose (1.25 mg) of indapamide and to determine if an improved safety profile could be produced while maintaining efficacy with a 1.25-mg dose in patients with mild to moderate essential hypertension. Four hundred seventeen (417) adult patients with mild to moderate essential hypertension (sitting diastolic blood pressure greater-than-or-equal 95 mmHg and less-than-or-equal 110 mmHg) were enrolled in two clinical studies; 209 patients were randomized to indapamide 1.25 mg and 208 patients to placebo. Patients received single-blind placebo for a 4-week washout period followed by an 8-week double-blind treatment period during which patients received either indapamide 1.25 mg or placebo. The primary efficacy endpoint was the mean change from baseline to week 8 in sitting diastolic blood pressure. Secondary efficacy variables were the proportion of patients whose sitting diastolic blood pressure had decreased greater-than-or-equal 10 mmHg and/or had a sitting diastolic blood pressure of less-than-or-equal 90 mmHg (treatment success) at all visits and at endpoint, mean changes from baseline in sitting diastolic blood pressure at designated timepoints and at endpoint, and mean changes from baseline in standing diastolic blood pressure and in sitting and standing systolic blood pressure at all visits and at endpoint. Results of these trials were pooled in order to have a larger patient population in an attempt to detect trends not readily apparent with a smaller sample size. In the primary analysis, indapamide produced statistically significantly (p = 0.0001) greater reductions in sitting diastolic blood pressure than placebo after 8 weeks of therapy. In the secondary analysis, the percentage of indapamide-treated patients who achieved treatment success after 8 weeks of therapy was statistically significantly (p < 0.0001) higher compared to placebo-treated patients. In addition, indapamide produced a statistically significantly (p = 0.0001) superior reduction compared to placebo in sitting systolic and standing systolic and diastolic blood pressure after 8 weeks of therapy. The incidence of drug-related adverse events between patients in the indapamide and placebo groups was similar. There were no clinically meaningful differences in laboratory values, including serum potassium, between the patients in the indapamide and placebo groups. Low-dose (1.25 mg) indapamide proved to be safe and effective in the treatment of mild to moderate hypertension.

• Authors: Robert Weiss, Phillip Toth, E. Eugene Miller, Stephen R. Zellner, Michael Shook, Joseph Codispoti, Arthur Stokes, Charles McNally
• Journal: American journal of therapeutics (Am J Ther) Vol. 1 Issue 1 Pg. 58-64 (Jun 1994) ISSN: 1536-3686 [Electronic] United States
• PMID: 11835068 (Publication Type: Journal Article)