Skip to main content


Generic name: metoprololme-TOE-pro-lol ]
Brand names: Kapspargo Sprinkle, Lopressor, Metoprolol Succinate ER, Metoprolol Tartrate, Toprol-XL
Drug class: Cardioselective beta blockers

What is Lopressor?

Lopressor is a beta-blocker that affects the heart and circulation (blood flow through arteries and veins).

Lopressor is used to treat angina (chest pain) and hypertension (high blood pressure). It is also used to lower your risk of death or needing to be hospitalized for heart failure.

Lopressor may also be used for other purposes not listed in this medication guide.

Important Information

You should not use Lopressor if you have a serious heart problem (heart block, sick sinus syndrome, slow heart rate), severe circulation problems, severe heart failure, or a history of slow heart beats that caused fainting.

Before taking this medicine

You should not use this medicine if you are allergic to Lopressor, or other beta-blockers (atenolol, carvedilol, labetalol, nadolol, nebivolol, propranolol, sotalol, and others), or if you have:

Tell your doctor if you have ever had:

Do not give this medicine to a child without medical advice.

Tell your doctor if you are pregnant or plan to become pregnant. It is not known whether Lopressor will harm an unborn baby. However, having high blood pressure during pregnancy may cause complications such as diabetes or eclampsia (dangerously high blood pressure that can lead to medical problems in both mother and baby). The benefit of treating hypertension may outweigh any risks to the baby.

Ask a doctor before using this medicine if you are breast-feeding. Metoprolol can pass into breast milk and may cause dry skin, dry mouth, diarrhea, constipation, or slow heartbeats in your baby.

How should I take Lopressor?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Lopressor should be taken with a meal or just after a meal.

Take the medicine at the same time each day.

Swallow the capsule whole and do not crush, chew, break, or open it.

A Toprol XL tablet can be divided in half if your doctor has told you to do so. Swallow the half-tablet whole, without chewing or crushing.

Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

You will need frequent medical tests, and your blood pressure will need to be checked often.

If you need surgery, tell the surgeon ahead of time that you are using Lopressor.

You should not stop using Lopressor suddenly. Stopping suddenly may make your condition worse.

If you have high blood pressure, keep using Lopressor even if you feel well. High blood pressure often has no symptoms. You may need to use Lopressor for the rest of your life.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Skip the missed dose and use your next dose at the regular time. Do not use two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking Lopressor?

Avoid driving or hazardous activity until you know how Lopressor will affect you. Your reactions could be impaired.

Drinking alcohol can increase certain side effects of metoprolol.

Lopressor side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

Common side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Lopressor?

Tell your doctor about all your current medicines. Many drugs can affect Lopressor, especially:

This list is not complete and many other drugs may affect Lopressor. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Popular FAQ

Metoprolol is not likely to cause weight gain. However, weight gain can be a warning sign that heart failure is getting worse. If you are taking metoprolol for heart failure, tell your doctor right away if you gain weight suddenly. This weight gain is due to extra fluid in the body that may cause swelling in the feet, ankles, legs and belly. The fluid builds up because the heart isn’t working as well as it should.

Yes, metoprolol causes the blood vessels to relax, which helps to lower blood pressure. If you are prescribed metoprolol for high blood pressure, your doctor may ask you to check your blood pressure regularly at home with an automatic, cuff-style device that goes around your upper arm. Keeping track of your blood pressure at home is one way to help your doctor know if the prescribed dosage of metoprolol is working for you.

When you take metoprolol depends on which salt form is prescribed.

  • Metoprolol tartrate is usually taken twice daily, so it may be taken in the morning then at night.
  • Metoprolol succinate is taken once daily, so it may be taken either morning or night.
  • Both forms are usually taken with or immediately after a meal.

Follow your health care provider’s directions for when to take metoprolol.

Research has suggested that taking your blood pressure medication at night instead of in the morning can provide better blood pressure control at night without compromising daytime blood pressure control and reduce your overall risk of dying because of cardiovascular disease by 45%. Continue reading

Metoprolol is available as two different salts: metoprolol tartrate and metoprolol succinate.

The main difference between metoprolol tartrate and metoprolol succinate is that metoprolol tartrate is only available as an immediate-release tablet which means it must be taken several times per day, whereas metoprolol succinate is an extended-release tablet that can be taken once a day. As a result, there are differences in the dosages and indications for both metoprolol tartrate and metoprolol succinate and they are not considered interchangeable. Continue reading

The half life of Metoprolol is between 3 and 7 hours. This is the time it takes for the drug levels in your plasma to reduce by half.

For a drug to be totally eliminated from your system it takes around 5.5 times the half life. As an estimate then, after taking a dose of Metoprolol it should be out of your system within 16.5 to 38.5 hours. Continue reading

How long it takes metoprolol to work depends on what form is given and what condition is being treated. Effects on heart rate can be seen within one hour after taking metoprolol tartrate tablets and within 20 minutes after the intravenous form is given. The onset of action of metoprolol succinate is similar to metoprolol tartrate. Continue reading

Metoprolol succinate and metoprolol tartrate contain the same active drug, metoprolol. The only difference is the salt form. Similar side effects may occur. Continue reading

No, metoprolol is not a blood thinner. It works to relax blood vessels and slow heart rate. Continue reading

Further information

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.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.