The Pressure's On

By Ian K. Smith, M.D.

Many patients suffering from high blood pressure were probably surprised last week to hear that one of the most popular class of drugs for treating their condition--calcium channel blockers--was being blamed for some 85,000 avoidable heart attacks and heart failures a year. Their doctors were less likely to be surprised. They know that treating hypertension can be tricky and that these particular drugs have been under intense scrutiny for the past five years.

Calcium channel blockers were introduced 20 years ago to great fanfare in part because the science seemed so easy to follow. The drugs work by blocking calcium from initiating muscle contractions in the heart and the walls of blood vessels. This allows blood vessels to relax, reducing blood pressure. More than 28 million people, including 12.7 million in the U.S., take the drugs under a variety of brand names, from Adalat to Verelan.

That may change after last week's report, delivered at a meeting of the European Cardiology Society in Amsterdam. Researchers reviewing studies involving 27,000 patients in nine clinical trials found that the risk of heart attack was 27% greater--and the risk of heart failure 26% greater--among users of calcium channel blockers than among patients taking other hypertension drugs.

What are those other drugs? The good news is that there is quite a broad array, from old standbys like diuretics to the latest designer drugs like ACE inhibitors.

Diuretics, commonly referred to as water pills, work by prompting the body to eliminate excess water. They are among the oldest drugs for hypertension, but they are still considered safe and effective, and should be part of any first-line therapy.

Beta-blockers have also been around for some time and have a good safety record. Their action isn't completely understood, but much of the benefit seems to come from reducing the heart rate. Patients suffering from poor circulation or respiratory disease, however, should look to other drugs.

ACE inhibitors, now among the most widely prescribed drugs for hypertension, are the new kids on the block. They work by blocking an enzyme that constricts blood vessels. They are particularly beneficial when the patient is suffering from diabetic kidney disease or congestive heart failure.

Alpha-blockers, which work on the sympathetic nervous system to reduce blood pressure, used to be widely prescribed. But a report earlier this year showed that they significantly increase the risk of heart attacks, and many physicians began changing their patients' prescriptions. Doctors then as now warned that dropping any blood-pressure medication can be dangerous, and should be done only under a doctor's careful supervision. One of the calcium blocker manufacturers believes clinical decisions should not be based on this type of study alone.

Most of the more than 50 million Americans who suffer from high blood pressure will eventually need some combination of medications. But drugs can do only so much. Doing it naturally--with simple lifestyle changes such as losing weight, exercising more, reducing salt intake and drinking less alcohol--can be just as effective and lead to a lot fewer complications.

Dr. Ian appears on WNBC-TV in New York. E-mail: ianmedical@aol.com For more on blood pressure, visit www.nhlbi.nih.gov