TUESDAY, Aug. 16, 2016 (HealthDay News) -- Doctors might be overprescribing beta-blocker medications to heart patients who aren't seriously ill, a new study contends.

Beta blockers such as Inderal (propranolol) and Lopressor (metoprolol) reduce blood pressure and control abnormal heart rhythms. They're lifesaving when given to patients who've had a heart attack or have heart failure, said study co-author Dr. Valay Parikh. He is a cardiology fellow with North Shore LIJ-Staten Island University Hospital, in Staten Island, N.Y.

But these drugs do not appear to help patients who haven't had a heart attack or have heart failure, even if they did need angioplasty -- surgery to clear a blocked artery that caused chest pain, Parikh and his colleagues report.

"Beta blocker therapy should be individualized, and these medications should not be given blindly to everyone," Parikh concluded. "They should be properly prescribed, based on each patient's indications."

Besides Inderal and Lopressor, common beta blocker brand names include Tenormin (atenolol), Zebeta (bisoprolol) and Sectral (acebutolol).

Heart doctors commonly prescribe beta blockers for their patients, said Dr. Deepak Bhatt, executive director of interventional cardiovascular programs at Brigham and Women's Hospital in Boston.

Beta blockers protect people from a follow-up heart attack or progressive heart failure. They also can help ease chest pain in people with a partially blocked artery who haven't undergone angioplasty, the procedure used to clear a blockage, said Bhatt.

However, Parikh said it hasn't been proven that beta blockers are beneficial for people who've received angioplasty to relieve chest pain symptoms, or angina.

Reduced flow of blood to the heart due to a blocked artery creates a supply-and-demand problem for which there are two possible strategies, explained Dr. Spencer King, president of the Heart and Vascular Institute at Saint Joseph's Health System in Atlanta.

A doctor can decrease the heart's demand for oxygenated blood by prescribing beta blockers, or open the artery and increase blood flow by performing angioplasty, King said.

"The question is, should you keep taking beta blockers after you've potentially corrected the restriction in blood flow through angioplasty," he added.

King is also editor-in-chief of the journal JACC: Cardiovascular Interventions, the journal in which the article was published on Aug. 16.

To examine this question, Parikh and his colleagues reviewed records for more than 755,000 heart patients who were treated between January 2005 and March 2013. They focused solely on patients who received angioplasty for recurring chest pain, but who had not suffered either a heart attack or heart failure.

More than 71 percent of these patients had been prescribed a beta blocker, and the use of beta blockers for angioplasty patients increased during the eight-year study period, Parikh said.

"We give it to all patients with heart disease, because we assume it's going to help," he said.

However, they found no significant difference between angioplasty patients taking beta blockers and those who were not.

Three years following surgery, the death rate was about the same for the two groups, as were the rates of heart attack and stroke, the researchers reported.

Also, 8 percent of patients taking beta blockers were readmitted to the hospital due to heart failure, compared to 6.1 percent of patients not on the medication.

Because beta blockers neutralize adrenaline, the drugs can have troubling side effects, Parikh said. They can make people feel worn down, tired or mentally confused, and can have a bad effect on blood sugar and cholesterol levels.

"If you are on a beta blocker and you haven't had a heart attack or heart failure, definitely you should talk to your doctor," Parikh said. "But keep taking them in the meantime. If you have been taking them for a long time, stopping them immediately can be harmful."

King said the results indicate that doctors should reconsider use of beta blockers for patients following angioplasty.

However, he believes the matter should be subjected to a clinical trial before treatment guidelines are changed. "It does raise a serious hypothesis that perhaps more study of this in a randomized fashion should be done, to confirm it," King said.

Bhatt said the new study is part of a growing amount of data that indicates doctors should become more judicious in their use of beta blockers.

"If a beta blocker is not helping and only causing side effects, that's a problem," Bhatt said.

More information

The American Heart Association explains how beta blockers affect exercise.