The beta blocker atenolol (also known as Tenoretic or Tenormin) is widely used to treat high blood pressure. In fact, many trials of blood pressure medicines have used it as a reference to compare other drugs with. But, researchers in Sweden say, maybe our confidence in atenolol is misplaced.

What the researchers wanted to know: Does atenolol reduce heart disease and death in people with high blood pressure?

What they did: The researchers dug up 17 randomized controlled trials that included atenolol as one of the treatments. Of those 17, eight met their standards to be included in this meta-analysis of the data. Four of the eight trials compared atenolol with another drug, three compared it with a placebo, and one had all three arms—atenolol, another drug, and a placebo.

What they found: In the four studies comparing atenolol with a placebo, atenolol was much better at lowering blood pressure. But atenolol did not reduce mortality in general, mortality due to cardiovascular causes, or heart attacks. The risk of stroke did seem to be lower, but that wasn't statistically significant. In the studies that compared atenolol with other blood pressure drugs, atenolol and the other drugs were equally good for lowering blood pressure, but the risk of mortality was significantly higher on atenolol. People on atenolol were also more likely to die from cardiovascular causes and to have strokes.

What the study means to you: Atenolol may not be the best drug to start people on when they're diagnosed with high blood pressure. It's particularly interesting that even though atenolol brought blood pressure down, it didn't provide the health benefits that you'd expect with lower blood pressure, like fewer heart attacks and a longer life. The researchers say this could have something to do with the drug's chemistry. It doesn't easily penetrate the nervous system, which some studies have suggested beta blockers need to do to prevent heart attacks.

Caveats: The researchers don't know how atenolol causes the patterns they reported. Also, studies with inconclusive results may be less likely to get published, so they might not have found every single atenolol trial ever done.

Find out more: Information about atenolol from the National Library of Medicine, including the important warning that stopping the drug abruptly could be deadly

Read the article: Carlberg, B. et al. "Atenolol in Hypertension: Is It a Wise Choice?" The Lancet. Nov. 6, 2004, Vol. 364, pp. 1684–1689.

Abstract online: www.sciencedirect.com