Diuretics should be first line treatment for hypertension

Question What agent is preferred as first line treatment for hypertension?

Synopsis Current evidence clearly supports using diuretics as the first line treatment for hypertension in most patients, including those with diabetes, coexisting risk factors for cardiovascular disease, and asymptomatic left ventricular hypertrophy (see the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure for exceptions). The authors combined 42 clinical trials including 192 478 patients randomised to seven major treatment strategies, including placebo. Most recently included in this meta-analysis were the antihypertensive and lipid-lowering treatment to prevent heart attack trial (ALLHAT) and the Australian national blood pressure study. None of the other first line treatment strategies, including β blockers, angiotensin converting enzyme (ACE) inhibitors, calcium channel blockers, α blockers, and angiotensin receptor blockers, were significantly better than low dose diuretics for any outcome (despite the fact that most cost considerably more). Compared with calcium channel blockers, diuretics were associated with a reduced risk of cardiovascular events and congestive heart failure. Compared with ACE inhibitors, diuretics were associated with reduced risks of congestive heart failure, cardiovascular events, and stroke. Compared with β blockers, diuretics were associated with a reduced risk of cardiovascular events. Blood pressure changes were similar with the different drugs (so much for that as a surrogate marker). In the largest trial (ALLHAT), low dose diuretics were also shown to have the lowest rate of dropouts due to intolerance and were also superior or equal to other agents, including ACE inhibitors, in patients with diabetes and asymptomatic left ventricular hypertrophy.

Bottom line It can't get clearer. Diuretics—the least expensive and most effective agents—should be the first line treatment almost everyone with hypertension, including patients with diabetes and asymptomatic left ventricular hypertrophy. Remember that the dose of the diuretic cannot be higher than an equivalent dose of 25 mg hydroclorothiazide. A higher dose creates an increased risk of mortality and morbidity without any additional benefit. Anyone who continues to prescribe a calcium channel blocker as a first line agent for uncomplicated hypertension should have their car trunk checked for large amounts of drug company paraphernalia and interrogated about who paid for their dinner the night before.

Level of evidence 1a (see www.infopoems.com/resources/levels.html); systematic reviews (with homogeneity) of randomised controlled trials.