When short-acting nifedipine, a calcium-channel blocker used to treat angina pectoris, was shown in the last decade to actually increase the risk of heart problems, people became understandably nervous about the drug, also known as Adalat or Procardia. But many thought long-acting versions of the drug, which are formulated so your body takes up the drug gradually, wouldn't have the same problem. In a new trial, researchers around the world looked at the safety and efficacy of long-acting nifedipine.

What the researchers wanted to know: Does long-acting nifedipine help patients with stable symptomatic coronary disease?

What they did: More than 7,500 patients at 291 centers in 19 countries were randomly assigned to take nifedipine or a placebo. Patients were 35 years or older, had angina, and needed treatment to prevent angina attacks. Some had had heart attacks, and some hadn't. Eighty percent of patients were also taking a beta blocker. Researchers followed the patients for 4.5 to 6 years or until they died.

What they found: Death rates were not significantly different for patients on nifedipine and patients on a placebo. They were also equally likely to have gotten on with no major cardiovascular event like a heart attack or stroke.

What the study means to you: Long-acting nifedipine seems to be safe. It's not as clear that it's effective at reducing cardiovascular events and deaths.

Caveats: In an editorial that appeared in the same issue of the journal as this study, two cardiovascular researchers point out that the conclusion that nifedipine is "safe" has to be qualified: 99 percent of the study population was on other heart drugs, and, while the study didn't find a significant difference in death rates, its statistics suggested that nifedipine could reduce mortality by 9 percent compared with a placebo or increase it by 25 percent. They recommend only using long-acting nifedipine after other drugs have failed to treat angina or high blood pressure.

Find out more: Information on nifedipine from Medline

Read the article: Poole-Wilson, P.A., et al. "Effect of Long-Acting Nifedipine on Mortality and Cardiovascular Morbidity in Patients with Stable Angina Requiring Treatment (ACTION Trial): Randomised Controlled Trial." The Lancet. Sept. 4, 2004, Vol. 364, pp. 849–857.

Abstract online: www.ncbi.nlm.nih.gov