Features December 2012 Issue

Research Shows Beta Blockers May Not Be Best For Hypertension

The widely used drugs do have other helpful purposes, however.

If you’re taking beta blockers to help control your high blood pressure and prevent a heart attack or stroke, a recent study suggests you may be better off with a different medication.

An observational study, published in the Oct. 3 issue of the Journal of the American Medical Association (JAMA), found that beta blocker use is not associated with lower risks of heart attack, stroke and mortality. And in some patient groups, such as individuals with risk factors for heart disease but no heart attack history, beta blocker use was actually associated with worse outcomes.

Beta blockers are usually prescribed to people with high blood pressure, and they have become the fifth most widely prescribed medications in the U.S., with an estimated 20 million Americans currently taking the drug. But this recent report suggests that beta blockers may have been over-prescribed through the years. Or at the very least, they are not the best drugs of choice for heart attack prevention.

Though cardiologist Steven Nissen, MD, Chairman of the Robert and Suzanne Tomsich Department of Cardiovascular Medicine at Cleveland Clinic, isn’t a fan of observational studies, he does acknowledge that beta blockers aren’t the right drugs for everyone. “They’re not a great choice for hypertension,” he says. “But we have strong evidence that shows beta blockers can extend life after MI (myocardial infarction, or heart attack).”

How Beta Blockers Function
Beta blockers (beta-adrenergic blocking agents) reduce the effectiveness of the hormone epinephrine, also known as adrenaline. Beta blockers help make the heart beat more slowly and with less force, thereby reducing blood pressure. Certain types of beta blockers also help open up blood vessels to improve blood flow.

But beta blockers, are of course, one of several types of anti-hypertensive medications. Others, such as diuretics, angiotensin-converting-enzyme (ACE) inhibitors, and calcium-channel blockers are generally considered safer and more effective medications to treat high blood pressure, Dr. Nissen says. “Beta blockers should really be fourth- or fifth-line drugs for hypertension,” he adds.

Beta blockers also carry certain side effects that may contribute to their association with worse cardiovascular outcomes in some patients. For example, beta blockers can raise cholesterol and triglyceride levels in some patients, but not all. The drugs can also lead to headaches, dizziness and upset stomach in some users. However, it’s worth noting that many patients take beta blockers without suffering any side effects.

Another common, nagging side effect of beta blockers can be sleep problems. But a recent study found that melatonin can help offset those complications. A small study, reported in the October issue of the journal Sleep, found that among individuals taking beta blockers, those who took 2.5 milligrams of melatonin each night slept an average of 36 minutes more each night than study subjects who took a placebo.
Advantages of beta blockers

Despite research that shows beta blocker use is not associated with lower cardiovascular risks, the medications are effective in other ways. Beta blockers are often prescribed immediately after a heart attack because they lessen the workload of the heart. Dr. Nissen notes that research has shown beta blockers offer heart protection for the first year or two after a heart attack, but adds that there isn’t significant research to show the longer term benefits of beta blocker use in heart attack patients.

That same concern was echoed in the JAMA study, which used data of 44,000 patients in the REACH (Reduction of Atherothrombosis for Continued Health), registry. The researchers wrote, “Further research is warranted to identify subroups that benefit from beta blocker therapy and the optimal duration of beta blocker therapy.”

Dr. Nissen adds that beta blockers are also effective in patients who experience angina, chest pain due to reduced blood flow to the heart muscle. Dr. Nissen explains that because beta blockers slow the heart rate, they can help delay the onset of angina. That means you can exercise longer before your heart muscle starts to the feel the effects of a reduced supply of oxygen-rich blood.

“If you’re on a beta blocker for high blood pressure, talk with your doctor about it and see if you should make a change,” Dr. Nissen says. “If you’re taking it for angina or if you’ve recently had a heart attack, stay on it.”