Popular Blood Pressure Drugs Linked to Cancer

June 14, 2010— -- Some widely used blood pressure drugs may be associated with an increased risk of cancer, researchers found in a new study.

In a meta-analysis of nine published studies the blood pressure drugs called angiotensin-receptor blockers were associated with a modest but statistically significant 8 percent increase in the relative risk of a new cancer, according to Dr. Ilke Sipahi, and colleagues at Case Western Reserve University School of Medicine in Cleveland, Ohio.

Angiotensin-receptor blockers, or ARBs, are a drug class that includes Diovan, Cozaar, Micardis, and Atacand.

A full list of the study drugs can be found at the bottom of the story.

On the other hand, there was no increase in the risk of dying from cancer, perhaps because follow-up in the trials was too short, the researchers said online in the medical journal The Lancet.

The findings are "disturbing and provocative" and raise important safety issues both for doctors and regulators, argued Dr. Steven Nissen, of the Cleveland Clinic, in an accompanying Comment article in the journal.

Nissen said regulators should immediately review the possible association and "promptly report" what they find. In the meantime, he added, doctors should use the drugs with caution, perhaps prescribing angiotensin-converting enzyme inhibitors instead.

The study comes only days after the U.S. Food and Drug Administration said it was evaluating data from two clinical trials in which patients with type 2 diabetes taking the blood pressure drug olmesartan (Benicar) had a higher rate of death from a cardiovascular causes compared to patients taking a placebo. Olmesartan was not studied by Sipahi and colleagues in the recent article.

Sipahi told MedPage Today that the study is only a first cut at the issue and needs to be followed by prospective studies aimed at the issue. But, he noted, "tens of millions of patients" use the drugs, so even a small increase in risk could be important.

Other experts, though, challenged the findings, saying the study was flawed. And many said they feared that publicity would lead to patients stopping what are very often life-saving medications.