Generic Name: Lopressor Brand Name(s): Generics only. No brands available.


What is Lopressor® (metoprolol tartrate) used for?

Lopressor® is commonly used for treating high blood pressure, alone or with other medicines; long-term treatment of chest pain; and reducing the risk of death because of heart problems in patients who have had a heart attack. It may also be used for other conditions as determined by your doctor.

Lopressor® is a beta-adrenergic blocking agent (beta-blocker). It works by reducing the amount of work the heart has to do (reduces chest pain) and the amount of blood the heart pumps out (lowers high blood pressure). It is also used to stabilize the heart rhythm in conditions in which the heart is beating too fast or in an irregular rhythm.

How should I take Lopressor® (metoprolol tartrate)?

Use Lopressor® as directed by your doctor. Check the label on the medicine for exact dosing instructions.

Lopressor® is usually given as an injection at your doctor’s office, hospital, or clinic. If you will be using Lopressor® at home, a health care provider will teach you how to use it. Be sure you understand how to use Lopressor®. Follow the procedures you are taught when you use a dose. Contact your health care provider if you have any questions.

Do not use Lopressor® if it contains particles, is cloudy or discolored, or if the vial is cracked or damaged.

Keep this product, as well as syringes and needles, out of the reach of children and pets. Do not reuse needles, syringes, or other materials. Ask your health care provider how to dispose of these materials after use. Follow all local rules for disposal.

How do I store Lopressor® (metoprolol tartrate)?

Lopressor® is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store Lopressor® in the bathroom or the freezer. There may be different brands of Lopressor® that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush Lopressor® down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using Lopressor® (metoprolol tartrate)?

Before using this drug, tell your doctor if:

  • You are pregnant or breastfeeding. This is because, while you are expecting or feeding a baby, you should only take medicines on the recommendation of a doctor.
  • You are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
  • You have allergy with any of active or inactive ingredients of Lopressor® or other medications.
  • You have any other illnesses, disorders, or medical conditions.
  • You have an adrenal gland tumor (pheochromocytoma), an overactive thyroid, or are scheduled to have surgery.
  • You have low blood pressure or a history of heart attack, slow or irregular heartbeat, heart failure, or other heart problems; chest pain or angina; blood circulation problems; or liver problems.
  • You have diabetes mellitus, chronic obstructive pulmonary disease (COPD), bronchitis, breathing problems, or a history of asthma

Is it safe during pregnancy or breastfeeding?

There are no adequate studies in women for determining risk when using Lopressor® during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking Lopressor®. Lopressor® is pregnancy risk category C, according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk
  • B=No risk in some studies
  • C=There may be some risk
  • D=Positive evidence of risk
  • X=Contraindicated
  • N=Unknown

Side effects

What side effects can occur from Lopressor® (metoprolol tartrate)?

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most common side effects persist or become bothersome:

  • Constipation
  • Diarrhea
  • Dizziness
  • Dry mouth or eyes
  • Gas
  • Headache
  • Heartburn
  • Lightheadedness
  • Mild drowsiness
  • Muscle aches
  • Nausea
  • Pain, redness, or swelling at the injection site
  • Stomach pain
  • Trouble sleeping
  • Unusual tiredness or weakness
  • Vomiting

Seek medical attention right away if any of these severe side effects occur:

  • Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue, unusual hoarseness)
  • Blue or unusually cold hands or feet
  • Chest pain
  • Chills, fever, or sore throat
  • Fainting
  • Hallucinations
  • Mood or mental changes (e.g., confusion, depression, foggy thinking, short-term memory loss)
  • Pounding in the chest
  • Severe dizziness or lightheadedness
  • Shortness of breath
  • Slow or irregular heartbeat
  • Swelling of the arms, hands, and feet
  • Unusual bruising or bleeding
  • Vision changes
  • Wheezing
  • Yellowing of the skin or eyes

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.


What drugs may interact with Lopressor® (metoprolol tartrate)?

Lopressor® may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Products that may interact with this drug are:

  • Amiodarone, bupropion, cimetidine, digoxin, diltiazem, diphenhydramine, disopyramide, flecainide, certain HIV protease inhibitors (e.g., ritonavir), hormonal contraceptives (e.g., birth control pills), hydralazine, hydroxychloroquine, ketanserin, mefloquine, mibefradil, monoamine oxidase inhibitors (MAOIs) (e.g., phenelzine), phenothiazines (e.g., thioridazine), propafenone, propylthiouracil, quinazolines (e.g., alfuzosin), quinidine, reserpine, certain selective serotonin reuptake inhibitors (SSRIs) (e.g., fluoxetine, paroxetine), terbinafine, or verapamil because serious side effects, such as very slow heart rate, very low blood pressure, fainting, severe dizziness, or lightheadedness when standing, may occur.
  • Clonidine because stopping it or Lopressor suddenly can lead to a rapid increase in blood pressure.
  • Barbiturates (e.g., phenobarbital), indomethacin, or phenylpropanolamine because they may decrease Lopressor’s effectiveness.
  • Bupivacaine, disopyramide, flecainide, hydralazine, ketanserin, or lidocaine because the risk of their side effects may be increased by Lopressor.

Does food or alcohol interact with Lopressor® (metoprolol tartrate)?

Lopressor® may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with Lopressor® (metoprolol tartrate)?

Lopressor® may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.


The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using Lopressor® (metoprolol tartrate).

What is the dose of Lopressor® (metoprolol tartrate) for an adult?


The usual initial dosage of Lopressor tablets is 100 mg daily in single or divided doses, whether used alone or added to a diuretic. Increase the dosage at weekly (or longer) intervals until optimum blood pressure reduction is achieved.

In general, the maximum effect of any given dosage level will be apparent after 1 week of therapy. The effective dosage range of Lopressor® tablets is 100-450 mg per day.

Dosages above 450 mg per day have not been studied.

While once-daily dosing is effective and can maintain a reduction in blood pressure throughout the day, lower doses (especially 100 mg) may not maintain a full effect at the end of the 24-hour period, and larger or more frequent daily doses may be required.

This can be evaluated by measuring blood pressure near the end of the dosing interval to determine whether satisfactory control is being maintained throughout the day. Beta1 selectivity diminishes as the dose of Lopressor® is increased.

Angina Pectoris

The usual initial dosage of Lopressor® tablets is 100 mg daily, given in two divided doses. gradually increase the dosage at weekly intervals until optimum clinical response has been obtained or there is pronounced slowing of the heart rate.

The effective dosage range of Lopressor® tablets is 100-400 mg per day. Dosages above 400 mg per day have not been studied.

What is the dose of Lopressor® (metoprolol tartrate) for a child?

The dosage has not been established in pediatric patients. It may be unsafe for your child. It is always important to fully understand the safety of the drug before using. Please consult with your doctor or pharmacist for more information.

How is Lopressor® (metoprolol tartrate) available?

Lopressor® is available in the following dosage forms and strengths:

  • tablet: metoprolol tartrate 50mg

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of Lopressor®, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.


Review Date: August 22, 2017 | Last Modified: September 2, 2017

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