Should we switch from bendrofluazide to chlorthalidone as the initial treatment for hypertension? A review of the available medication

Abstract

INTRODUCTION Thiazide diuretics are commonly prescribed in the treatment of hypertension. However, thiazide diuretics may not all be equal in their ability to reduce cardiovascular disease outcomes. AIM To determine if bendroflumethiazide/bendrofluazide, the most commonly used diuretic for hypertension in New Zealand, is as effective as other diuretics in terms of cardiovascular disease outcomes. METHODS Using recent reviews of thiazide-like (chlorthalidone or indapamide) and thiazide-type diuretics (hydrochlorothiazide and bendrofluazide) and a separate search of bendrofluazide, data on cardiovascular disease outcomes was extracted. RESULTS Nineteen relevant papers with 21 comparisons were found. All thiazide-based diuretics have been reported in at least one trial showing them to be more effective than placebo for cardiovascular disease outcomes, with the exception of chlorothiazide. There were no comparisons of bendrofluazide alone with other medications, but there were two studies with either bendrofluazide or hydrochlorothiazide compared with β-blockers; however, the pooled relative risk (RR) was not significant (RR = 1.10 (95% CI, 0.84-1.43)). For chlorthalidone, there were four comparisons with other medications, and the summary RR was statistically significant for cardiovascular disease outcomes (RR = 0.91 (95% CI, 0.85-0.98)). Chlorthalidone was significantly more effective for some cardiovascular disease outcomes when compared with doxazosin, amlodipine and lisinopril. CONCLUSIONS All thiazide-based medicines available in New Zealand are effective in terms of cardiovascular disease outcomes compared with placebo when used for treating hypertension, with the exception of chlorothiazide. Of the diuretics available in New Zealand for hypertension, only chlorthalidone has been shown to be more effective than other blood pressure-lowering medicines. It may be time to change from using bendrofluazide and start using chlorthalidone as a treatment for hypertension.