A study in the NEJM titled "The effect of nisoldipine as compared with enalapril on cardiovascular outcomes in patients with non-insulin-dependent diabetes and hypertension," finds an increased risk of fatal and non-fatal heart attacks among individuals taking the calcium antagonist nisoldipine compared to individuals taking enalapril, which is a member of a class of drugs called ACE-inhibitors.
The study provides more evidence that calcium antagonists (preferred term for calcium channel blockers) may pose risks for certain people, including those with diabetes and coronary heart disease. Past studies of short-acting calcium antagonists have also found increased risk of cardiovascular complications. It was thought that the longer-acting drugs did not pose similar risks. However, the current study used a long-acting drug.
Speaking for the American Heart Association, Joseph Izzo, M.D., says "individuals taking calcium antagonists should not panic and stop medication without consulting a physician. However, individuals with both known cardiovascular disease and diabetes may want to talk to their physicians about choosing another type of high blood pressure drug, or to use the calcium antagonist in combination with other agents that are complementary." Izzo is a member of the American Heart Association's Continuing Education Committee.
Calcium antagonists dilate (relax) constricted blood vessels and thus reduce blood pressure. However, this vasodilator action may force the heart to pump harder and may also stimulate stress hormones. This action is the opposite of beta-blockers that limit cardiac output, notes Izzo, professor of medicine and pharmacology at the State University of New York, Buffalo.
The study, by Raymond Estacio, M.D., of the Colorado Prevention Center, Denver, included 470 individuals who had high blood pressure and non-insulin dependent diabetes. The trial compared an ACE-inhibitor with a calcium antagonist in the prevention and progression of diabetes in equal number of individuals. A secondary goal of the study was to determine if the drugs could prevent cardiovascular disease, a leading cause of death among individuals with diabetes.
The study found that nisoldipine (Sular) was linked with a higher rate of fatal and non-fatal heart attacks -- a total of 25 compared to five for enalapril in this particular group. Despite these striking differences, the authors of the study stress that "it is plausible that the findings resulted from a protective effect of enalapril and not a deleterious effect of nisoldipine."
Other calcium antagonists include: nimodipine (Nimotop); verapamil (Calen, Isoptin, Verelan); nicardipine (Cardene); diltiazem (Cardizem, Dilacor); isradipine (DynaCirc); amlodipine (Norvasc); felodipine (Plendil); nifedipine (Procardia); and bepridil (Vascor).
Contact: Carole Bullock, AHA News Media Relations: (214) 706-1279.
Journal
New England Journal of Medicine