Beta blockers, also called beta-adrenergic blocking agents, treat a variety of conditions, such as high blood pressure, glaucoma and migraines. Find out more about this class of medication. By Mayo Clinic Staff

Beta blockers, also known as beta-adrenergic blocking agents, are medications that reduce your blood pressure. Beta blockers work by blocking the effects of the hormone epinephrine, also known as adrenaline. When you take beta blockers, the heart beats more slowly and with less force, thereby reducing blood pressure. Beta blockers also help blood vessels open up to improve blood flow.

Some beta blockers mainly affect your heart, while others affect both your heart and your blood vessels. Which one is best for you depends on your health and the condition being treated.

Examples of beta blockers include:

  • Acebutolol (Sectral)
  • Atenolol (Tenormin)
  • Bisoprolol (Zebeta)
  • Metoprolol (Lopressor, Toprol-XL)
  • Nadolol (Corgard)
  • Propranolol (Inderal LA, InnoPran XL)

Doctors prescribe beta blockers to prevent, treat or improve symptoms in a variety of conditions, such as:

  • High blood pressure
  • Irregular heart rhythm (arrhythmia)
  • Heart failure
  • Chest pain (angina)
  • Heart attacks
  • Glaucoma
  • Migraines
  • Generalized anxiety disorder
  • Hyperthyroidism
  • Certain types of tremors

Beta blockers aren't usually prescribed until other blood pressure medications, such as diuretics, haven't worked effectively. Your doctor may prescribe beta blockers as one of several medications to lower your blood pressure, including angiotensin-converting enzyme (ACE) inhibitors, diuretics or calcium channel blockers.

Beta blockers may not work as effectively for blacks as for people of other races, especially when taken without other blood pressure medications.

Side effects may occur in people taking beta blockers. However, many people who take beta blockers won't have any side effects.

Common side effects of beta blockers include:

  • Fatigue
  • Cold hands
  • Headache
  • Upset stomach
  • Constipation
  • Diarrhea
  • Dizziness

Less common side effects include:

  • Shortness of breath
  • Trouble sleeping
  • Loss of sex drive
  • Depression

Beta blockers generally aren't used in people with asthma because of concerns that the medication may trigger severe asthma attacks. In people who have diabetes, beta blockers may block signs of low blood sugar, such as rapid heartbeat. It's important to monitor your blood sugar on a regular basis.

Beta blockers can also affect your cholesterol and triglyceride levels, causing a slight increase in triglycerides and a modest decrease in high-density lipoprotein, the "good" cholesterol. These changes often are temporary. You shouldn't abruptly stop taking a beta blocker because doing so could increase your risk of a heart attack or other heart problems.

Feb. 01, 2014