Beta blockers are medications used to lower blood pressure and manage heart rhythms. See a list of the different types of beta blocker such as metoprolol, atenolol, and more. Read about a group of medicines called beta blockers, including what they're used for, side effects and what to do if you miss a dose or take too much. Metoprolol is used to treat angina (chest pain) and hypertension (high blood pressure). Learn about side effects, interactions and indications. Beta-blockers are often prescribed for irregular heartbeats, high blood pressure, and after heart attacks. Learn more about how they work. Beta blockers are medicines that lower blood pressure. They also may be called beta-adrenergic blocking agents. These medicines block the effects of the hormone epinephrine, also known as adrenaline. Beta blockers cause the heart to beat more slowly and with less force. This lowers blood pressure. In short, beta-blockers slow down your heart rate and relax smooth muscle tissue in your blood vessels. Learn other ways they affect your body. Beta blockers are a class of drug used for treating abnormal heart rhythms, angina, high blood pressure, migraine, anxiety, and more. Side effects of beta blockers include diarrhea, stomach cramps, nausea and vomiting, rash, blurred vision, muscle cramps, and fatigue, although they are generally well tolerated. Doctors have long prescribed drugs called beta blockers (which slow down the heart and lower blood pressure) to all people who've had a heart attack. But growing evidence suggests these drugs offer. Beta blockers are used to treat irregular heart rhythms, chest pain, heart attack, hypertension, migraine headaches, social phobias, tremors, and glaucoma. Common side effects of beta blockers are nausea, vomiting, abdominal cramps, diarrhea, and weight gain if you are taking medicine for diabetes (type 1 and type 2). Examples of generic and brand names available for beta blockers in the U.S. Beta blockers, also spelled β-blockers and also sometimes known as β-adrenergic receptor antagonists, are a class of medications predominantly used to manage abnormal heart rhythms (arrhythmia) and to protect the heart from a second heart attack after the first one (secondary prevention). [1] They are also used widely to treat high blood pressure, though they are no longer the first choice.