PRECAUTIONS: Before taking metoprolol, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: certain types of irregular heartbeats (e.g., sinus bradycardia, second or third degree atrioventricular block), cardiogenic shock, severe heart failure (overt or decompensated type), a certain type of tumor (untreated pheochromocytoma). Before using this medication, tell your doctor or pharmacist your medical history, especially of: heart failure (treated, compensated type), breathing problems (e.g., asthma, chronic obstructive lung disease), diabetes, overactive thyroid disease (hyperthyroidism), liver disease, blood circulation problems (e.g., Raynaud's disease), skin conditions (e.g., psoriasis), mental/mood disorders (e.g., depression), certain muscle disease (myasthenia gravis). Before having surgery, tell your doctor or dentist that you are taking this medication. If you have diabetes, this medication may mask the fast/pounding heartbeat you would usually feel when your blood sugar level falls too low (hypoglycemia). Other symptoms of a low blood sugar level such as dizziness or sweating are unaffected by this drug. This drug may make you dizzy or drowsy; use caution engaging in activities requiring alertness such as driving or using machinery. Limit alcoholic beverages. To minimize dizziness and lightheadedness, get up slowly when rising from a seated or lying position. This medication should be used only when clearly needed during pregnancy. Discuss the risks (e.g., low birth weight) and benefits with your doctor. This drug passes into breast milk. While there have been no reports of harm to nursing infants, consult your doctor before breast-feeding.

DRUG INTERACTIONS: This drug should not be used with the following medications because very serious interactions may occur: mibefradil, psychiatric drugs (phenothiazines such as chlorpromazine, thioridazine). If you are currently using any of these medications, tell your doctor or pharmacist before starting this drug. Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription products you may use, especially of: alpha-blockers (e.g., prazosin), anti-diabetic drugs (e.g., glipizide, glyburide, insulin), barbiturates (e.g., phenobarbital), calcium channel blockers (e.g., diltiazem, verapamil), cimetidine, epinephrine, general anesthesia, non-steroidal anti-inflammatory drugs (e.g., indomethacin, ibuprofen), other heart drugs (e.g., amiodarone, digoxin, propafenone, quinidine, intravenous lidocaine), other drugs to treat high blood pressure (e.g., clonidine, hydralazine, reserpine), medications for overactive thyroid disease (e.g., methimazole, propylthiouracil), paroxetine, rifamycins (e.g., rifampin), St. John's wort. Check the labels on all your medicines (e.g., cough-and-cold products, diet aids) because they may contain ingredients that could increase your heart rate or blood pressure. Ask your pharmacist about the safe use of those products. Do not start or stop any medicine without doctor or pharmacist approval.

Report Problems to the Food and Drug Administration You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088. Need help identifying pills and medications? Use the pill identifier tool on RxList.