Beta blockers are medicines that affect the body's response to certain nerve impulses. This, in turn, decreases the force and rate of the heart's contractions, which lowers blood pressure and reduces the heart's demand for oxygen.

The main use of beta blockers is to treat high blood pressure. Some also are used to relieve the type of chest pain called angina or to prevent heart attacks in people who already have had one heart attack. These drugs may also be prescribed for other conditions, such as migraine headache, tremors, and irregular heartbeat. As eye drops they are used to treat certain kinds of glaucoma.

Beta blockers, also known as beta-adrenergic blockers, are available only with a physician's prescription. Some common beta blockers are atenolol (Tenormin), metoprolol (Lopressor), nadolol (Corgard), propranolol (Inderal), and timolol (Blocadren). Eye drops that contain beta blockers include betaxolol (Betoptic), cartelol (Ocupress), and...