This medication is a beta-blocker. This drug works by blocking the action of certain natural chemicals in your body (such as epinephrine) that affect the heart and blood vessels. This lowers heart rate, blood pressure, and strain on the heart.

This drug is used to treat chest pain (angina), heart failure, and high blood pressure. Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems.

•  Drowsiness, dizziness, tiredness, diarrhea, and slow heartbeat may occur. Decreased sexual ability has been reported rarely.
•  To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.
•  This drug may reduce blood flow to your hands and feet, causing them to feel cold. Smoking may worsen this effect. Dress warmly and avoid tobacco use.
•  Tell your doctor right away if any of these unlikely but serious side effects occur: very slow heartbeat, severe dizziness, fainting, blue fingers/toes, trouble breathing, new or worsening symptoms of heart failure (such as shortness of breath, swelling ankles/feet, unusual tiredness, unusual/sudden weight gain), mental/mood changes (such as confusion, mood swings, depression).
•  A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

o Before taking metoprolol, tell your doctor or pharmacist if you are allergic to it; or to other beta-blockers (such as atenolol, propranolol); or if you have any other allergies.

• Before using this medication, tell your doctor or pharmacist your medical history, especially of: certain types of heart rhythm problems (such as a slow heartbeat, second- or third-degree atrioventricular block, sick sinus syndrome), breathing problems (such as asthma, chronic bronchitis, emphysema), liver disease, serious allergic reactions, including those needing treatment with epinephrine, blood circulation problems (such as Raynaud's disease, peripheral vascular disease), mental/mood disorders (such as depression), a certain muscle disease (myasthenia gravis).
• If you have diabetes, this product may mask the fast/pounding heartbeat you would usually feel when your blood sugar falls too low (hypoglycemia). Other symptoms of low blood sugar, such as dizziness and sweating, are unaffected by this drug. This product may also make it harder to control your blood sugar. Check your blood sugar regularly as directed and share the results with your doctor. Tell your doctor right away if you have symptoms of high blood sugar such as increased thirst/urination. Your doctor may need to adjust your diabetes medication, exercise program, or diet.
• Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
• o This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit or avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).
• During pregnancy, this medication should be used only when clearly needed. It may harm an unborn baby. Discuss the risks and benefits with your doctor.
• This drug passes into breast milk. Discuss the risks and benefits with your doctor before breast-feeding.