For more than half a century, medications known as beta blockers have been a mainstay for treating heart disease, especially for heart attack survivors. But now doctors are reconsidering that strategy, based on growing evidence showing that for some people who have had a heart attack, beta blockers may not offer any significant benefit. “For people whose hearts are still pumping normally after a heart attack, doctors can now think twice before prescribing a beta blocker,” says Dr. Cian McCarthy, a cardiologist at Harvard-affiliated Massachusetts General Hospital.
Sometimes, however, a heart attack leaves the left ventricle (the heart’s main pumping chamber) unable to contract effectively. When that’s the case, beta blockers are still recommended, he says. These medications are also prescribed to treat angina (chest pain caused by narrowing of the heart arteries), to treat heart failure, to suppress abnormal heart rhythms such as atrial fibrillation, and to treat high blood pressure.
What are beta blockers?
You can identify beta blockers by their generic names; They all end in “lol.” Common examples include
- atenolol (tenormin)
- bisoprolol
- carvedilol (Coreg)
- metoprolol (Lopressor, Toprol)
- nadolol
- propranolol (Inderal, InnoPran).
How do beta blockers work in the body?
Beta blockers work by blocking beta receptors, which are small proteins found on the outer surfaces of cells throughout the body, especially in the heart, blood vessel walls, lungs, kidneys, and brain. Stress hormones (i.e., epinephrine and norepinephrine) stimulate beta receptors, triggering effects that vary by organ. In the heart and blood vessels, epinephrine and norepinephrine speed up the heart, strengthen the heart’s contractions, and tighten the walls of blood vessels.
Beta blockers subvert these effects by locking into beta receptors and preventing stress hormones from binding to them. As a result, the heart slows and the blood vessels relax, actions that lower blood pressure and reduce the heart’s workload.
Common Side Effects of Beta Blockers
The side effects of beta blockers are not usually life-threatening. But because beta receptors are found in so many different tissues, these medications can have unwanted effects throughout the body, such as
- drowsiness or fatigue
- dizziness or lightheadedness
- cold hands and feet
- constipation
- erectile dysfunction.
Less common side effects include allergic reactions (such as rashes and swelling of the face) and difficulty sleeping. If you have side effects from a beta blocker, talk to your doctor.
Beta blockers after a heart attack
A recent study examined the role of beta blockers in more than 8,500 heart attack survivors with normal or slightly impaired heart function. Half were randomly assigned to start taking a beta blocker within two weeks of discharge from the hospital; the others did not take beta blockers. Over the next four years, researchers found no difference in repeat heart attacks, hospitalizations for heart failure, or death from any cause between the two groups. Published on August 30, 2025 in The New England Journal of MedicineThe findings apply to people with normal or slightly reduced heart function, defined as an ejection fraction of 40% or more. Ejection fraction refers to the percentage of blood that the heart sends to the rest of the body each time it contracts. An ejection fraction of 50% to 70% is considered normal.
Who should (and who shouldn’t) take beta blockers?
If you have had a heart attack and have what is called a reduced ejection fraction (an ejection fraction less than 40%), a beta blocker still makes sense. People with a slightly reduced ejection fraction (40% to 49%) are also likely to benefit from beta blockers. But if you have a preserved ejection fraction (40% or more), a beta blocker may not be necessary. What if you have a preserved ejection fraction and are already taking a beta blocker? “It may be reasonable to stop taking it a year after the heart attack, as long as you don’t need the medication for another reason,” Dr. McCarthy says.
Beta blockers are generally less effective than other blood pressure medications at preventing cardiovascular problems, especially strokes. “But while beta blockers are not a first-line option, they can still be a helpful addition if your blood pressure remains uncontrolled while taking other medications,” says Dr. McCarthy.
Beta blockers are also used to prevent migraine attacks and decrease hand tremors. They can dampen common symptoms of anxiety, such as sweating, tachycardia, and blushing. Beta-blocking eye drops are commonly prescribed to reduce eye pressure in people with glaucoma. If you are currently taking a beta blocker for any reason, do not stop taking it before talking to your doctor.
This article appears in the January 2026 issue of Harvard Heart Letter under the title “New ideas on the use of beta blockers.”
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