The question

Taking one blood pressure medication is not always enough to keep high blood pressure (hypertension) under control, sometimes prompting doctors to prescribe a second drug. With the additional medication, though, often come additional side effects. Might there be a better option?

This study

The researchers analyzed data from 42 studies, involving 20,284 adults (average age, 54) with hypertension who had been randomly assigned to taking a placebo or blood-pressure-lowering medication in varying combinations and dosages. Medications included calcium channel blockers, beta blockers, angiotensin receptor blockers (ARBs), angiotensin-converting enzyme (ACE) inhibitors and thiazide diuretics (TZs). Among those taking medication, some took a full dose and some took a quarter-dose; others took a combination of two drugs at a quarter-dose each or a combination of four drugs at a quarter-dose each.

After an average of seven weeks, blood pressure measurements showed that taking a quarter-dose of one medication did not lower blood pressure as much as a full dose did. However, taking a ­quarter-dose of a two-drug combination was just as effective at lowering blood pressure as taking a full dose of one drug, and taking a quarter-dose of a four-drug combination proved more effective. Those who took the smaller doses of a combination of drugs had fewer side effects than those taking one drug at full dose and no more side effects than those taking a placebo.

Who may be affected?

People taking medication because of hypertension, which makes the heart and blood vessels work harder and less efficiently. Uncontrolled, hypertension can lead to a heart attack, stroke or kidney failure. In addition to medication, methods to control hypertension — and possibly prevent it — include being physically active, not becoming overweight, eating healthfully, drinking alcohol only in moderation and not smoking. About 1 of every 3 adults in the United States has high blood pressure, but just over half of them have it under control.


The researchers did not attribute results to specific medications. Just one study included a four-drug combination. Two of the 19 researchers are named as inventors for an institute that has applied for patents for the development of drug combinations, including those for blood pressure lowering.

Find this study

Online June 6 in Hypertension (hyper.ahajournals.org).

Learn more about

Find information on hypertension at nhlbi.nih.gov and heart.org.