Study Sees Risk in Blood Pressure Drugs

Adding fuel to a hotly debated controversy, a study released today reports that elderly people who took calcium-channel blocker drugs, the nation’s biggest-selling blood pressure medications, had a slightly higher risk of developing cancer than people who did not take the drugs.

The data are the latest in a dispute touched off last year when a survey of studies suggested that one particular calcium-blocker, nifedipine, was associated with a higher than normal death rate. That finding prompted the National Heart, Lung and Blood Institute to warn that the drug be prescribed “with great caution (if at all).”

The new study, led by Dr. Marco Pahor of the University of Tennessee in Memphis, analyzed the medical records of 5,052 people 71 and older in Massachusetts, Connecticut and Iowa. Of those, 451 said they had taken one of three calcium-channel blocking drugs.

Overall, the cancer rate was 70% higher among those who had taken the drugs compared to those who had not. The total number of cancers in the drug group was small--only 47--which kept the researchers from definitively linking the drug to any type of cancer.

Pahor said the study results should not necessarily prompt people to stop taking calcium-channel blocking drugs. But he added that other classes of blood pressure and heart disease medications, including the so-called beta-blockers and ACE-inhibitors, have been shown to be safer and more effective than calcium-channel blockers.

“I think patients and doctors should be aware that there are [other] drugs that are available to prevent [disease] and to increase survival,” he said.

There are two basic types of calcium-channel blockers. The original, fast-acting types, such as nifedipine, are the ones that have recently come into question. The newer, time-release formulations may pose less of a risk, researchers say.

Many of the 13 brands of calcium-channel blockers in the Physicians’ Desk Reference, including Adalat, Cardizem and Procardia, come in both the fast-acting and extended-release formulations.

The drug company Bayer, maker of the Adalat brand of nifedipine, strongly disputed the new findings in a statement. Its drug “has been on the market for more than 20 years and there is no evidence from an extensive analysis of Bayer’s 90,000-patient database or from the hundreds of nifedipine clinical trials that link the drug to the development of cancer,” the company said.

Researchers in Israel released their own study suggesting that calcium-channel blocker drugs caused no increase in cancer deaths over four years among 11,500 patients. “These results should end the . . . ‘scare’ brought on by sensationalized media reports, so that appropriate patients can continue to benefit from these safe and effective drugs,” said Henrietta Rechier-Reiss of the Tel Aviv Medical Center.

A Lancet editorial, referring to a “steady flow of data indicting this drug class,” urged that definitive studies be conducted.