Review Question(s)

In this first update of a review published in 2009, we wanted to determine which drug class was the best first-line choice in treating adult patients with raised blood pressure.

We searched the available medical literature to find all the trials that compared the drugs to placebo or no treatment to assess this question. The data included in this review are up to date as of November 2017.

Background

High blood pressure or hypertension can increase the risk of heart attacks and stroke. One of the most important decisions in treating people with elevated blood pressure is what drug class to use first. This decision has important consequences in terms of health outcomes and cost.

Study characteristics

We found no new trials in this updated search. In the original review, we found 24 studies that randomly assigned 58,040 adult people (mean age 62 years) with high blood pressure, to four different drug classes or placebo. Duration of these studies ranged from three to five years. Drug classes studied included thiazide diuretics, beta-blockers, ACE inhibitors, and calcium channel blockers.

Key Results

We concluded that most of the evidence demonstrated that first-line low-dose thiazides reduced mortality, stroke, and heart attack. No other drug class improved health outcomes better than low-dose thiazides. Beta-blockers and high-dose thiazides were inferior.

Conclusions

High-quality evidence supported that low-dose thiazides should be used first for most patients with elevated blood pressure. Fortunately, thiazides are also very inexpensive.

Quality of evidence

The evidence for first-line low dose thiazides was high quality. For the other classes, we judged the evidence to be moderate or low quality.