Patients suffering from arterial hypertension are generally asymptomatic but they are exposed to an increased risk of a cardiovascular event. The aim of an antihypertensive treatment is to reduce this risk and to reduce mortality. Pregnancy aside, for non-diabetic patients not suffering from cardiovascular or renal disorders, an antihypertensive drug is justified when their blood pressure is higher than 160/90 mm Hg or 160/100 mm Hg, shown in several tests taken under good conditions a few days apart. Antihypertensive treatment prevents around two or three deaths and two strokes per 100 patients treated for four to five years.

In 2014, according to clinical trial data, only low-dose thiazide diuretics and angiontensin converting enzyme (ACE) inhibitors have been proved to reduce overall mortality among hypertensive patients. Chlortalidone and hydrochlorothiazide are the best-evaluated diuretics. Low-dose chlortalidone is more effective than an ACE inhibitor in preventing strokes.

Overall, the adverse effects profile of thiazide diuretics is no less favourable that that of other groups of antihypertensive drugs.

When available, chlortalidone is a first-line option. In the absence of a non-combination chlortalidone-based product, hydrochlorothiazide is the first-choice diuretic. When a diuretic should be avoided, it is better to choose an ACE inhibitor such as captopril, lisinopril, or ramipril.

©Prescrire 1 September 2014

"Treating essential hypertension. The first choice is usually a thiazide diuretic" Prescrire Int 2014; 23 (152): 215-220. (Pdf, subscribers only).