Written by Rachel Nall | Published on November 11, 2013
Medically Reviewed by George Krucik, MD, MBA on November 11, 2013

What Is Metoprolol?

Brand Name: Lopressor, Toprol, Toprol XL; combination medications include Dutoprol, Lopressor, Lopressidone
Generic Name: metoprolol

Physicians prescribe metoprolol to lower high blood pressure and/or treat the symptoms of chest pain following a heart attack. Metoprolol belongs to a class of medications known as beta blockers. It used either alone or with other medications to reduce blood pressure.

Read the FDA description of metoprolol succinate.

Read the FDA description of metoprolol tartrate.

Spending too much at the pharmacy to keep your blood pressure down? Find out how you can pay less »

What Does Metoprolol Do?

Metoprolol is a beta-adrenergic blocking agent. This means it keeps the hormone epinephrine or adrenaline from acting on receptors in the body. Adrenaline can affect a number of body functions, including heart rate and blood vessel size. Metoprolol relaxes the blood vessels, which in turn reduces heart rate and blood pressure. While metoprolol is used to reduce high blood pressure and chest pain symptoms, it does not cure these symptoms; it only controls them.

Metoprolol is available in a number of preparations, including tablets, extended-release tablets, and injection.

While metoprolol’s uses are chiefly heart disease related, a physician may prescribe it to prevent migraine headaches, regulate an irregular heartbeat, or reduce movement side effects from taking medications for mental illness.

This information is a summary. Before starting this medication, discuss questions with your healthcare provider and make sure you understand dosage instructions.

What Should I Tell My Doctor Before Starting Metoprolol?

Tell your doctor if you:
  • have a heart block that is greater than first degree
  • are breastfeeding
  • are pregnant or could possibly be pregnant: metoprolol can cross the placental barrier and cause fetal injury, including the birth of infants that are small for gestational age
  • have asthma
  • have cardiogenic shock
  • have diabetes
  • have heart disease
  • have a history of allergic reaction to metoprolol or other beta blockers (medications ending in -olol), such as atenolol (Tenormin), carvedilol (Coreg), labetalol (Trandate), and propranolol (Inderal)
  • have hyperthyroidism
  • have liver disease
  • have lung disease
  • have overt (symptomatic) cardiac failure: beta blockers like metoprolol can depress the cardiac muscle’s ability to contract, which can lead to worsening heart failure
  • have renal conditions or impairment
  • have severe peripheral arterial circulatory disorder
  • have sinus bradycardia, a heart rhythm of less than 60 beats per minute that originates in the heart’s sinus node
  • have untreated pheochromocytoma

Drinking alcohol while taking metoprolol can increase fatigue. You should also tell your physician you are taking metoprolol before undergoing any type of surgery, including dental surgery.

What Medications May Interact with Metoprolol?

Always tell your physician about any prescription medications or herbal remedies you are taking.

Medications that can adversely interact with metoprolol include:

  • bupropion (Wellbutrin)
  • cimetidine (Tagamet)
  • clonidine  (Catapres)
  • diphenhydramine (Benadryl)
  • fluoxetine (Prozac, Sarafem)
  • hydroxychloroquine (Plaquenil)
  • paroxetine (Paxil)
  • propafenone (Rythmol)
  • quinidine (Quinaglute, Quinidex)
  • ranitidine (Zantac)
  • reserpine (Serpalan, Serpasil, Serpatab)
  • ritonavir (Norvir)
  • terbinafine (Lamisil)
  • thioridazine (Mellaril)

Possible Side Effects of Metoprolol

The following are severe and emergent side effects of these medications. Contact your medical provider immediately if you experience the following:

  • change in color of the fingertips, lips, skin, palms, or nail beds to blue
  • depression
  • loss of consciousness
  • wheezing (bronchospasm) or shortness of breath
  • worsening heart condition symptoms, such as low blood pressure and/or slow heart rate

The following side effects may occur, but do not usually represent an emergency. Discuss with your doctor or healthcare professional if they continue or are bothersome.

  • bloating
  • constipation
  • diarrhea
  • difficulty concentrating
  • difficulty sleeping
  • dizziness
  • dry mouth
  • fatigue
  • flatulence/gas
  • irritability
  • loss of sexual interest or performance
  • mental confusion
  • nausea
  • runny nose

This list may not describe all possible side effects. Call your doctor or healthcare provider for advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Where Should I Keep Metoprolol?

Metoprolol tablets and injection vials should be stored at room temperature—somewhere around 77 degrees Fahrenheit or 25 degrees Celsius. Keep the medication tightly closed in a light-resistant container.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

FDA WARNING: Metoprolol carries a black box warning (meaning the medication has potentially lethal side effects) for its potential to cause chest pain exacerbation in patients when the medication is suddenly discontinued. Do not stop taking your medication unless your doctor instructs you to do so.

The Healthline Site, its content, such as text, graphics, images, search results, HealthMaps, Trust Marks, and other material contained on the Healthline Site ("Content"), its services, and any information or material posted on the Healthline Site by third parties are provided for informational purposes only. None of the foregoing is a substitute for professional medical advice, examination, diagnosis, or treatment. Always seek the advice of a physician or other qualified healthcare provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on the Healthline Site. If you think you may have a medical emergency, call your doctor or 911 immediately. Please read the Terms of Service for more information regarding use of the Healthline Site.   

Was this article helpful? Yes No

Thank you.

Your message has been sent.

We're sorry, an error occurred.

We are unable to collect your feedback at this time. However, your feedback is important to us. Please try again later.

Show Sources

Read This Next

Pulmonary Arterial Hypertension Prognosis and Life Expectancy
Pulmonary Arterial Hypertension Prognosis and Life Expectancy
Pulmonary arterial hypertension treatment can ease symptoms and slow the progression, but this type of high blood pressure can be fatal. Learn about prognosis.
Drugs and Medications for Pulmonary Arterial Hypertension
Drugs and Medications for Pulmonary Arterial Hypertension
Treatment for pulmonary arterial hypertension often includes medicines to reverse or stop damage to your lung’s arteries. Learn about these medication options.
Relief from Chronic Migraine: Medications and Other Treatments
Relief from Chronic Migraine: Medications and Other Treatments
Medications and other treatments to help you get relief from chronic migraine symptoms.
What Are the Symptoms of Pulmonary Hypertension?
What Are the Symptoms of Pulmonary Hypertension?
Pulmonary hypertension (PH) occurs when arteries between the heart to the lungs narrow, making the heart work harder. Learn about symptoms and dangers of PH.
Non-Small Cell Adenocarcinoma: The Most Common Type of Lung Cancer
Non-Small Cell Adenocarcinoma: The Most Common Type of Lung Cancer
Adenocarcinoma is a cancer that begins in the glandular cells of internal organs, such as lungs. Non-small cell adenocarcinoma is a common type of lung cancer.