Metoprolol is used alone or in combination with other medications to treat high blood pressure. It also is used to prevent angina (chest pain) and to treat heart attacks. Extended-release (long-acting) metoprolol also is used in combination with other medications to treat heart failure. Metoprolol is in a class of medications called beta blockers. It works by slowing the heart rate and relaxing the blood vessels so the heart does not have to pump as hard.

Metoprolol is also used sometimes to prevent migraine headaches and to treat irregular heartbeat and movement disorders caused by medications for mental illness. Talk to your doctor about the possible risks of using this medication for your condition.

Special precautions

Before taking metoprolol,

• Do not stop taking metoprolol without talking to your doctor. Suddenly stopping metoprolol may cause chest pain or heart attack.
• You should know that if you have allergic reactions to different substances, your reactions may be worse while you are using metoprolol.
• Remember that alcohol can add to the drowsiness caused by this medication.
• You should know that metoprolol may make you drowsy. Do not drive a car or operate machinery until you know how this medication affects you.
• If you are having surgery, including dental surgery, tell the doctor or dentist that you are taking metoprolol.
• Tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking metoprolol, call your doctor.
• Tell your doctor if you have or have ever had asthma or other lung disease; diabetes; heart or liver disease; a slow heart rate; or an overactive thyroid gland (hyperthyroidism).
• tell your doctor and pharmacist if you are taking vitamins, nutritional supplements, and herbal products
• Tell your doctor and pharmacist if you are allergic to metoprolol or any other medicines.

Side effects

Metoprolol may cause side effects.

• cold hands and feet
• rash or itching
• constipation
• heartburn
• gas or bloating
• stomach pain
• dry mouth
• upset stomach
• depression
• tiredness
• dizziness or lightheadedness

Some side effects can be serious. The following symptoms are uncommon:

• rapid, pounding, or irregular heartbeat
• fainting
• unusual weight gain
• swelling of the hands, ankles, feet, or lower legs
• wheezing
• shortness of breath

Symptoms of overdose may include:

• swelling of the hands, ankles, feet, or lower legs
• difficulty breathing or swallowing
• fainting
• dizziness

Keep all appointments with your doctor. Your blood pressure should be checked regularly to determine your response to metoprolol