context: Beta-blockers are one of the most widely prescribed classes of drugs to treat hypertension (high blood pressure) and are a mainstay treatment of congestive heart failure. Beta-blockers work by blocking the effects of epinephrine (adrenaline) and slowing the heart's rate, thereby decreasing the heart's demand for oxygen. Long-term use of beta-blockers helps manage chronic heart failure. Acebutolol ( Sectral) Atenolol ( Tenormin) Bisoprolol ( Zebeta) Carvedilol ( Coreg) Esmolol ( Brevibloc) Labetalol ( Normodyne, Trandate) Metoprolol ( Lopressor, Toprol- XL) Propranolol ( Inderal) Doctors often prescribe beta-blockers for these heart conditions: Heart failure High blood pressure Angina Abnormal heart rhythms Heart attack Beta-blockers can also treat: Glaucoma Migraine headaches Anxiety Certain types of tremors Hyperthyroidism (overactive thyroid) If you have asthma or COPD, your doctor may not prescribe a beta-blocker because it may make your breathing symptoms worse. If you have heart failure and severe lung congestion, your doctor will treat your congestion before prescribing a beta-blocker. You can take them in the morning, at meals, and at bedtime. When you take them with food, you may have fewer side effects because your body absorbs the drug slower. Follow the label directions on how often to take it. The number of doses you take each day, the time allowed between doses, and how long you need to take the medication will depend on your condition. Older people typically take lower doses. Ask your doctor what to do if you miss a dose. While you're taking a beta-blocker, you may need to check your pulse every day. If it's slower than it should be, contact your doctor about taking your beta-blocker that day. Never stop taking a beta-blocker without speaking to your doctor first, even if you feel that it's not working. Sudden withdrawal can worsen angina and cause heart attacks. Side effects of beta-blockers are common but usually mild. They include: Fatigue Cold hands Upset stomach, diarrhea, or constipation Headache Dizziness Shortness of breath Trouble sleeping Loss of sex drive or erectile dysfunction Depression If these symptoms don't go away or become severe, contact your doctor. You shouldn't take beta-blockers if you have low blood pressure or a slow pulse, because bringing down your heart rate more can cause dizziness and lightheadedness. People who take beta-blocker often have other prescriptions, too. Typically, those are for a diuretic (''water pill'') or other medications such as ACE inhibitors and angiotensin receptor blockers ( ARBs), which lower blood pressure and improve heart failure symptoms. If you have side effects and you're taking your heart drugs together, talk to your doctor or pharmacist. You may need to change when you take each medication, so they're at different times. It's important to tell your doctor about everything you're taking -- including over-the-counter drugs, herbs, and supplements -- because they might affect how your beta-blocker works. Beta-blockers may affect a growing baby by slowing its heart rate and lowering its blood sugar level and blood pressure. These drugs can also pass to an infant through breast milk, causing low blood pressure, trouble breathing, and a slow heart rate. You should tell your doctor if you're trying to get pregnant or you become pregnant while on beta-blockers or are breastfeeding. Certain medications have been used successfully to treat conditions including heart failure, irregular heartbeat, high blood pressure, and migraines.