Beta blockers are often prescribed for heart arrhythmias (irregular heartbeat), high blood pressure, and after heart attacks. They’re a class of medication used to block the effects of stress hormones like adrenaline (also called epinephrine) on the heart. Less commonly, beta blockers may be used to treat glaucoma, migraines, anxiety disorders, hyperthyroidism, and tremors.
Physicians typically turn to beta blockers for high blood pressure when other medications like diuretics aren't working or have too many side effects. They may be used in combination with other blood pressure-lowering medications such as ACE inhibitors or calcium-channel blockers.
How They Work
Beta blockers are also called beta-adrenergic blocking substances due to the way they work in the body. Although different types of beta blockers work differently, in general, these medications enhance the heart's ability to relax. Your heart will beat slower and less forcefully when beta blockers are working. This can help to reduce blood pressure and alleviate irregular heart rhythms. While some beta blockers only work on the heart itself, others impact the heart and the blood vessels that serve it.
Your physician may prescribe beta blockers even if you have few symptoms of heart problems or heart failure. This is because these medications can actually improve the heart's ability to beat. Commonly prescribed beta blockers include:
- acebutolol (Sectral)
- atenolol (Tenormin)
- bisoprolol (Zebeta)
- carteolol (Cartrol)
- esmolol (Brevibloc)
- metoprolol (Lopressor, Toprol XL)
- nadolol (Corgard)
- nebivolol (Bystolic)
- propranolol (Ineral LA)
Beta blockers have been shown to have some additional positive health effects. For example, they protect bones by preventing the kidneys from excreting calcium into urine. Instead, these drugs block stress hormones that could otherwise cause thinning over time. Beta blockers aren’t a first line of treatment for thinning bones or osteoporosis. Stronger bones just may be an extra benefit of taking these medications.
Side Effects and Risks
People with asthma typically shouldn’t take beta blockers because they can trigger asthma attacks. Because beta blockers may affect the control of blood sugar, they’re usually not recommended for people with diabetes.
Side effects of these medications can vary. Many people will experience:
- cold hands
- digestive problems
Rarely, you may experience:
- shortness of breath
- trouble sleeping
- decreased libido
If you accidentally take a larger dose than recommended, you may experience:
- difficulty breathing
- changes in vision
- irregular heartbeats
If you know that an overdose has occurred, call your physician or local poison control center.
Some of the older beta blockers—including atenolol and metaprolol—have been reported to cause an average weight gain of four pounds. Fluid retention and accompanying weight gain can be signs of heart failure or worsening heart failure, so be sure to let your doctor know if you gain more than three to four pounds or if your symptoms worsen.
You also may notice some changes in the way your heart works during day-to-day life. For example, beta blockers prevent spikes in heart rate. You may notice that your heart rate doesn’t climb as high as it normally would during exercise. If you're concerned about your workouts while taking this medication, speak with your physician. They may recommend a stress test to determine your target heart rate during cardiac activity and your perceived exertion (how hard you feel you’re working during a workout).
Taking Your Medication
Beta blockers are often taken with meals, though they’ll come with special instructions. Take your medication as prescribed. Consult your doctor if you’re having side effects and don’t stop taking the medication without your doctor’s consent.