What to Know About Lopressor and Toprol XL (Metoprolol)

Medication for High Blood Pressure, Angina, Heart Failure

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Lopressor (metoprolol tartrate) and Toprol-XL (metoprolol succinate) are the immediate-release and extended release versions of metoprolol, a medication for treating high blood pressure (hypertension), angina, and other conditions relating to cardiovascular disease. Metoprolol does not cure these conditions, but rather is used to help manage them.

Uncommon Side Effects of Metoprolol

Theresa Chiechi / Verywell


Metoprolol belongs to a class of drugs known as beta blockers, because they block the effects of adrenaline on your body’s beta receptors, thereby slowing nerve impulses that travel through the heart. In that way, metoprolol relaxes your blood vessels and slows your heart rate in order to improve blood flow and lower your blood pressure.

Metoprolol is FDA-approved as an oral medication to treat high blood pressure (hypertension) and angina. The tablet and intravenous immediate-release version (Lopressor) is also FDA-approved for improving your chances of survival after a heart attack (acute myocardial infarction). The extended-release tablet (Toprol-XL) is also FDA-approved to treat heart failure.

Metropolol is also used in combination with the diuretic (water pill) hydrochlorothiazide under the brand names Dutoprol and Lopressor HCT to treat high blood pressure.

Metoprolol is used to lower blood pressure that is too high, meaning that you have a systolic pressure in your arteries (when your heart is beating) of 130 mm Hg or higher or a diastolic pressure (between heartbeats) of 80 mm Hg or higher.

The drug is also used to treat angina, which is severe chest pain that happens when your heart isn’t getting enough oxygen-rich blood. Angina is a symptom of coronary artery disease, when plaque builds up in your arteries and restricts blood flow.

Further, metoprolol can be used to reduce your chance of death after a heart attack, either as soon as you are stable enough for it to be administered by medical personnel or within three to 10 days of your heart attack.

Finally, the drug is used to treat heart failure, which happens when the heart is not pumping enough blood and oxygen to your organs.

Off-Label Uses

Metoprolol has been used to prevent migraine headaches. It also is used sometimes to treat irregular heartbeat, as well as movement disorders caused by drugs for mental illness.

Before Taking

If you have the following conditions, you may be prescribed metoprolol alone or in combination with other medications:

  • High blood pressure
  • Angina
  • Heart attack
  • Heart failure

Talk to your healthcare provider about all medications, supplements, and vitamins that you currently take. While some drugs pose minor interaction risks, others may outright contraindicate use or prompt careful consideration as to whether the pros of treatment outweigh the cons in your case.

Precautions and Contraindications

Do not stop taking metoprolol suddenly. To do so risks chest pain or a heart attack. Speak with your healthcare provider about the best way to discontinue the medication.

You should not be given metoprolol if have the following conditions:

  • Sinus bradycardia (a type of slow heartbeat)
  • Moderate-to-severe heart block
  • Cardiogenic shock (when your blood can’t pump blood to vital organs, such as the brain)
  • Moderate-to-severe heart failure
  • Pheochromocytoma (a tumor on a gland near the kidneys)
  • Severe peripheral arterial disease
  • Sick sinus syndrome (a type of irregular heartbeat)

Tell your healthcare provider if you are allergic or have problems with Lopressor, Topol-XL, Dutoprol, Lopressor HCT, or other beta blocker medications; or if you are taking other beta blockers.

Also let your healthcare provider know if you are pregnant, plan to become pregnant, or are breastfeeding; planning any kind of surgery (including dental); have diabetes; have had asthma or lung disease; have ever had an allergic reaction requiring epinephrine; or have hyperthyroidism

Other Beta Blockers

If you take other beta blockers, they may react with metoprolol in an unintended way, and they have similar contraindications. They include:

  • Betaxolol
  • Bystolic (nebivolol)
  • Coreg (carvedilol)
  • Corgard (nadolol)
  • Inderal (propranolol)
  • Inderal LA (propranolol)
  • Levatol (penbutolol)
  • Pindolol
  • Sectral (acebutolol)
  • Tenormin (atenolol)
  • Timolol
  • Trandate (labetalol)
  • Zebeta (bisoprolol)


Metoprolol is typically taken in the following dosages, according to the condition being treated. All listed dosages are according to the drug manufacturer. Check your prescription and talk to your healthcare provider to make sure you are taking the right dose for you.


  • Adults: 25-400 milligrams (mg) by mouth of Toprol-XL or 100-400 mg per day of Lopressor
  • Children: 1.0 mg per kg of weight daily, not to exceed 50 mg per day

Angina: 100-400 mg by mouth of Toprol-XL or Lopressor

Heart failure: 2.5-200 mg of Toprol-XL by mouth daily 

Heart attack: Three injections of Lopressor at 5 milliliters (mL) each initially, 100-200 mg of intravenous injections daily for the next 48 hours, followed by maintenance doses of 200 mg by mouth daily for at least 3 months.

How to Take and Store

Oral doses of metoprolol should be taken exactly as prescribed by your healthcare provider. Take it regularly and continuously, as directed, with or just after meals.

Keep metoprolol in a tightly closed container that protects the medication from light. It should be stored at a temperature between 59 F and 86 F (between 15 C and 30 C). Keep it out of the reach of children.

Side Effects


Taking metoprolol may result in drowsiness, which can intensify if you take alcohol.

Less Common

Less often, people taking this medication have the following symptoms:

  • Feeling dizzy or lightheaded
  • Fatigue
  • Depression
  • Stomach upset or pain
  • Dry mouth
  • Vomiting
  • Gas or bloating
  • Heartburn
  • Constipation
  • Runny nose
  • Rash or itchiness
  • Cold hands and feet


Rare, but serious side effects may include:

  • Shortness of breath or wheezing
  • Swollen hands, feet, ankles, or lower legs
  • Fainting
  • Rapid, pounding, or irregular heartbeat
  • Weight gain

Contact your healthcare provider if you are experiencing any side effects. If you are having an allergic reaction, seek emergency medical attention.

Warnings and Interactions

Metoprolol can have severe effects in some cases, as well as interactions with other medications.

Black Box Warning for Metoprolol

The FDA has a black box warning (the strongest warning the agency issues on its labels) against abruptly quitting your metropolol doses. To suddenly stop taking the medication may cause chest pain or a heart attack. Speak to your healthcare provider first, who will probably decrease your dose gradually. 

Possible Drug Interactions

Also, the following medications may interfere with the way metoprolol works, so let your healthcare provider know if you also take: 

  • Aplenzin (bupropion)
  • Benadryl (diphenhydramine)
  • Brisdelle (paroxetine)
  • Catapres (clonidine)
  • Cimetidine
  • Forfivo (bupropion)
  • Hydroxychloroquine
  • In Symbyax (fluoxetine)
  • Lamisil (terbinafine)
  • Norvir, in Kaletra (ritonavir)
  • Paxil (paroxetine)
  • Pexeva (paroxetine)
  • Prozac (fluoxetine)
  • Quinidine
  • Reserpine
  • Rythmol (propafenone)
  • Sarafem (fluoxetine)
  • Selfemra (fluoxetine)
  • Thioridazine
  • Wellbutrin (bupropion)
  • Zantac 360 (famotidine)
  • Zyban (bupropion)
10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. MedlinePlus, U.S. National Library of Medicine. Metoprolol.

  2. Texas Heart Institute. Beta-blockers.

  3. AstraZeneca .Dutoprol (metoprolol succinate extended release/hydrochlorothiazide). [Package Insert].

  4. Novartis Pharmaceuticals Corporation. Lopressor HCT T2007-77 metoprolol tartrate USP and hydrochlorothiazide USP. [Package Insert].

  5. American Heart Association. What is high blood pressure?

  6. MedlinePlus, U.S. National Library of Medicine. Angina.

  7. Novartis Pharmaceuticals Corporation. Lopressor (metoprolol tartrate) tablet, Lopressor (metoprolol tartrate) injection, solution. [Package Insert].

  8. Centers for Disease Control and Prevention. Heart failure.

  9. AstraZeneca. Toprol-XL (metoprolol succinate) extended-release tablets. [Package Insert].

  10. U.S. Food and Drug Administration. High blood pressure—medicines to help you.

By Sheryl Huggins Salomon
Sheryl Huggins Salomon is a veteran editor and health journalist specializing in coverage of metabolic health, skin conditions, and BIPOC health trends.