Warning Is Issued on Older Type of Blood Pressure Drug

People taking an old version of the drug nifedipine to treat high blood pressure should ask their doctors about changing medication, government scientists said Thursday. But they recommended no change for millions of Americans on other hypertension drugs.

The decision by scientific advisors to the Food and Drug Administration should help settle an intense controversy about a class of blood pressure drugs called calcium channel blockers.

“People have been very worried,” said FDA drug chief Dr. Robert Temple. For the vast majority of patients, “we didn’t see any reason to change their therapy.”

The only drug the FDA advisors expressed concern about was an old version of nifedipine, sold under the brand names Adalat and Procardia, that must be taken four times a day. Many doctors use a new, one-a-day version that appears very safe, the FDA emphasized.

But people taking the older, worrisome version should not stop taking it on their own because suddenly dropping a drug can cause a dangerous jump in blood pressure. Instead, they should see a doctor to discuss a better alternative, Temple said.

The controversy arose last summer when small studies suggested that calcium channel blockers could nearly triple patients’ death rates, and increase by 60% the risk of a heart attack.

The risk was considered enough for the FDA to debate whether to add a warning to the drugs’ labels that they should not be given to people at risk of a heart attack because of high blood pressure or a type of chest pain called unstable angina.

The FDA committee concluded that calcium channel blockers as a whole should not cause concern. In fact, the drug verapamil, sold as the brands Calan and Isoptin, actually decreased patients’ risk of worsening heart disease. The FDA usually follows the recommendations of its advisory panels.