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Doctors urged to curb reliance on beta-blockers

Research favors other drugs to control hypertension

Doctors should stop routinely using beta-blockers to control high blood pressure, said researchers who reviewed dozens of previously published studies and found that other hypertension pills work better and cause fewer side effects.

For decades, beta-blockers and diuretics, also known as water pills, constituted the cornerstone of treatment for the 50 million Americans with high blood pressure. But a growing body of medical evidence shows that diuretics and newer blood-pressure medications are superior to beta-blockers at reducing high blood pressure, which can lead to heart attacks and strokes, said researchers whose report appeared yesterday in the Journal of the American College of Cardiology.

"We in medicine like to say that we practice evidence-based medicine," said Dr. Franz H. Messerli, an author of the study and a cardiologist at St. Luke's-Roosevelt Hospital in New York. "What's the evidence here" for continued use of beta-blockers to treat hypertension, Messerli asked. "Zero. To my way of thinking, this is pretty alarming."

Heart specialists not involved with the study predicted that it is likely to accelerate a shift in hypertension treatment from beta-blockers, which can cause side effects such as fatigue and sexual dysfunction.

Still, those doctors as well as the authors of the study emphasized that there is strong evidence to support prescribing beta-blockers for patients who have suffered a heart attack or those with a progressive weakening condition called heart failure.

Data from IMS Health, a healthcare information company, show that from January through June of this year, more than 75 million prescriptions were written for various beta-blockers, widely available in generic form. The statistics do not indicate which conditions the doctors were treating.

European medical societies have already begun urging physicians to abandon beta-blockers as a high blood-pressure medication, specialists said.

"I think this paper is going to be fairly influential, although I think the trend had already started before this of moving away from beta-blockers as a first-line treatment of hypertension," said Dr. Joseph Carrozza, chief of interventional cardiology at Beth Israel Deaconess Medical Center. "The side effects are probably the worst" of any medication used to treat high blood pressure, he said.

Cardiologists said there is no clear culprit for the heavy use of beta-blockers. Early research suggested that the drugs had promise in treating high blood pressure, though they were often used with diuretics, which turned out to provide much of the benefit.

Also, beta-blockers have been around for decades and in recent years, their patents had expired, so they were relatively inexpensive, doctors said.

"This is just another example of why we need to do continuing follow-up research on classes of medicine," said Alan Goldhammer, deputy vice president for regulatory affairs at PhRMA, a leading pharmaceutical industry association.

One possible limitation in the new research: It was based on previous studies that looked at older beta-blockers, rather than some recently introduced formulations.

Still, Dr. Ilke Sipahi, a cardiologist at the Cleveland Clinic, said "until further data comes out, I think it's prudent not to use beta-blockers as a first-line treatment of high blood pressure."

The National Heart, Lung, and Blood Institute had already planned to convene specialists this fall to draft sweeping guidelines directing physicians toward the best treatments for their patients with cardiovascular ailments.

Dr. Lawrence J. Fine, acting chief of the national agency's Clinical Applications and Prevention Branch, said the new study will be factored into those recommendations. "Clearly, these authors have raised issues that new assessments of guidelines will have to consider seriously," Fine said.

In patients with high blood pressure, once-flexible blood vessels have turned rigid, meaning more pressure is needed to propel blood through veins and arteries.

To treat the condition, doctors use four major classes of high blood pressure pills: beta-blockers, diuretics, calcium-channel blockers, and ACE inhibitors.

Beta-blockers, sold under trade names such as Lopressor and Tenormin, work by blocking the effect of the hormone adrenaline on the heart. As a result, the heart slows down and does not have to work as hard. That's especially useful in the treatment of patients who have suffered heart attacks and those whose hearts chronically malfunction.

While beta-blockers reduce blood pressure, the other drugs do so more effectively and with fewer complications, the authors of yesterday's study said.

For example, the researchers cite an earlier analysis of 10 medical studies involving elderly patients with high blood pressure. About two-thirds of the patients taking diuretics had their blood pressure controlled, compared with less than one-third of the patients on beta-blockers.

Diuretics, among the most affordable drugs patients can take, reduce blood pressure by helping the body excrete excess water and sodium. They are widely regarded as the preferred first-line treatment for blood pressure patients, because of their low cost and mild side effects.

The later-generation drugs -- calcium-channel blockers and ACE inhibitors -- relax blood vessel walls, allowing blood to flow more smoothly.

While high blood pressure patients taking beta-blockers have a reduced risk of stroke of 16 percent to 22 percent compared with a placebo, the other hypertension drugs reduce that risk by an average of 38 percent.

Conversely, beta-blockers are powerfully beneficial for patients who have suffered heart attacks, substantially reducing the chances that they will soon die.

Beta-blockers also may work well for patients whose high blood pressure is not controlled by the other medications. Patients should not stop taking blood pressure drugs without first talking to their doctor. "We have the luxury now of a lot of drugs, and we can use the different ones for different situations," said Dr. Aram V. Chobanian, former dean of the Boston University School of Medicine. "The more we find out about these individual drugs, the more we will know about what specific patient populations they should be used in."

Stephen Smith can be reached at stsmith@globe.com.

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