Lopressor is a brand-name prescription drug. It’s FDA-approved for use in adults to:

Drug details

Lopressor contains the active drug metoprolol tartrate. It’s a type of drug called a beta-blocker. Beta-blockers work by preventing certain hormones in your body from attaching to beta receptors.*

By preventing the hormones from attaching to the receptors, Lopressor helps to:

  • lower blood pressure
  • decrease chest pain
  • reduce stress on your heart

Lopressor comes as tablets that are taken by mouth. It’s available in two strengths: 50 mg and 100 mg. You’ll likely take Lopressor once or twice a day, either with food or shortly after eating.

* Beta receptors are proteins on the surface of cells in your heart, blood vessels, and lungs. They enable substances, such as the molecules of a drug, to attach to the protein and relay a chemical message.

Effectiveness

For information on the effectiveness of Lopressor, see the “Lopressor uses” section below.

Lopressor contains the active drug ingredient metoprolol tartrate, which is also available as a generic drug. A generic drug is an exact copy of the active drug in a brand-name medication. The generic is considered to be as safe and effective as the original drug. Generics tend to cost less than brand-name drugs.

Generic Lopressor comes as an injectable solution and as tablets that are taken by mouth. The tablets come in strengths of 25 milligrams (mg), 50 mg, and 100 mg.

Lopressor can cause mild or serious side effects. The following lists contain some of the key side effects that may occur while taking Lopressor. These lists do not include all possible side effects.

For more information on the possible side effects of Lopressor, talk with your doctor or pharmacist. They can give you tips on how to deal with any side effects that may be bothersome.

Note: The Food and Drug Administration (FDA) tracks side effects of drugs they have approved. If you would like to report to the FDA a side effect you’ve had with Lopressor, you can do so through MedWatch.

Mild side effects

Mild side effects of Lopressor can include*:

Most of these side effects may go away within a few days or a couple of weeks. But if they become more severe or don’t go away, talk with your doctor or pharmacist.

* This is a partial list of mild side effects from Lopressor. To learn about other mild side effects, talk with your doctor or pharmacist, or visit Lopressor’s prescribing information.
† For more information on these side effects, see “Side effect details” below.

Serious side effects

Serious side effects from Lopressor aren’t common, but they can occur. Call your doctor right away if you have serious side effects. Call 911 or your local emergency number if your symptoms feel life threatening or if you think you’re having a medical emergency.

Serious side effects and their symptoms can include:

* For more information on these side effects, see “Side effect details” below.

Side effect details

You may wonder how often certain side effects occur with this drug. Here’s some detail on certain side effects this drug may cause.

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Lopressor. But it isn’t known how many adults in clinical studies had an allergic reaction to Lopressor.

Symptoms of a mild allergic reaction can include:

  • skin rash
  • itchiness
  • flushing (warmth and redness in your skin)

A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include:

  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your tongue, mouth, or throat
  • trouble breathing

Call your doctor right away if you have a severe allergic reaction to Lopressor. But call 911 or your local emergency number if your symptoms feel life threatening or if you think you’re having a medical emergency.

Weight gain

Lopressor may cause weight gain in some people. But it isn’t known how many people gained weight while using Lopressor in clinical studies. And the amount of weight that people gained while using this drug during studies isn’t known, either.

Other studies have shown that drugs such as Lopressor that contain metoprolol may cause weight gain. Specifically, in these studies, metoprolol caused an average weight gain of 2.6 to 4.4 pounds (1.2 to 2.0 kg). These studies also found that the risk of weight gain may be highest during the first few months after you start taking drugs that contain metoprolol.

If you’re concerned about gaining weight while taking Lopressor, talk with your doctor. They may monitor your weight during treatment. And they can recommend ways to help you manage a body weight that’s healthy for you.

Hair loss

Hair loss is a rare potential side effect of Lopressor. It isn’t known how common hair loss was in clinical studies of the drug. But hair loss from Lopressor is thought to be reversible. This means hair that’s lost because of Lopressor should grow back after you stop taking the drug.

However, you shouldn’t stop taking Lopressor without first talking with your doctor. Suddenly stopping Lopressor can cause serious heart problems. (For more information about this, see the “Common questions about Lopressor” section below.)

If you have concerns about losing hair while taking Lopressor, talk with your doctor.

Side effects in older people

Side effects of Lopressor in older people are thought to be the same as they are in younger people. Clinical studies of Lopressor in adults ages 65 years and older didn’t show any differences in side effects for this age group.

But keep in mind that older people may have other health conditions that affect how their bodies respond to Lopressor. And these conditions could increase people’s risk for side effects from the drug.

Because of this, it’s recommended that people ages 65 years and older start with a low dosage of Lopressor. (For more information on Lopressor dosing, see the “Lopressor dosage” section below.) And their Lopressor dosage may be increased over time until the drug works well to treat their condition.

If you’re concerned about using Lopressor given your age, talk with your doctor about the risks and benefits of using this drug. Your doctor can recommend if this is an appropriate drug to treat your condition.

Tiredness

Lopressor may cause tiredness in some people taking the drug. In clinical studies, tiredness occurred in 1% to 10% of people who took Lopressor. (The percentage varied depending on the condition being treated.) The length of time that people felt tired while taking Lopressor isn’t known.

If you have tiredness that’s bothersome while you’re taking Lopressor, talk with your doctor. They may suggest ways to help lessen this side effect and improve your energy level.

Diarrhea

Diarrhea is a common side effect of Lopressor. In clinical studies, diarrhea occurred in 5% of people who took this drug for high blood pressure or chest pain. The percentage of people who had diarrhea after taking Lopressor for a possible heart attack isn’t known. And it’s not known how long people had diarrhea in clinical studies.

If you have bothersome diarrhea while taking this medication, talk with your doctor. They can recommend ways to help reduce your diarrhea.

Depression

It’s possible to have feelings of depression while you’re taking Lopressor. In clinical studies, about 5% of people with high blood pressure or chest pain had depression after taking Lopressor. It isn’t known how many people with possible heart attack had this side effect after taking Lopressor.

Symptoms of depression can include:

  • changes in appetite, such as feeling more or less hungry than usual
  • changes in sleep, making you sleep more or less than usual
  • changes in mood
  • feelings of agitation or restlessness
  • lack of energy
  • loss of interest in activities that you normally enjoy
  • suicidal thoughts
  • trouble with concentration
  • trouble making decisions
  • weight gain or weight loss that isn’t intentional

If you experience any of these symptoms, tell your doctor right away. They can recommend ways to help manage your depression symptoms. But if you have thoughts of harming yourself, call 911 or your local emergency number.

Suicide prevention

If you know someone at immediate risk of self-harm, suicide, or hurting another person:

  • Ask the tough question: “Are you considering suicide?”
  • Listen to the person without judgment.
  • Call 911 or the local emergency number, or text TALK to 741741 to communicate with a trained crisis counselor.
  • Stay with the person until professional help arrives.
  • Try to remove any weapons, medications, or other potentially harmful objects.

If you or someone you know is having thoughts of suicide, a prevention hotline can help. The National Suicide Prevention Lifeline is available 24 hours per day at 800-273-8255. During a crisis, people who are hard of hearing can call 800-799-4889.

Click here for more links and local resources.

The Lopressor dosage your doctor prescribes will depend on several factors. These include:

  • the type and severity of the condition you’re using Lopressor to treat
  • your age
  • other medical conditions you may have

Typically, your doctor will start you on a low dosage. Then they’ll adjust it over time to reach the amount that’s right for you. Your doctor will ultimately prescribe the smallest dosage that provides the desired effect.

The following information describes dosages that are commonly used or recommended. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.

Drug forms and strengths

Lopressor comes as a tablet that’s taken by mouth. It’s available in two strengths: 50 milligrams (mg) and 100 mg.

You should take Lopressor with food or right after eating.

Dosage for high blood pressure

Lopressor is approved to treat high blood pressure. For this purpose, Lopressor may be used alone or in combination with other blood pressure medications. But dosages of Lopressor are the same whether Lopressor is used alone or with other drugs.

The typical starting dosage of Lopressor for high blood pressure is 100 mg once a day or 50 mg twice a day. The maintenance dosage for this condition ranges from 100 mg daily to 450 mg daily.

Your doctor may recommend a different dosage for you depending on several factors. These factors include your age or whether you have liver disease. Talk with your doctor about the dosage that’s best for you.

Dosage for chest pain

Lopressor is approved to treat stable angina, which is a type of chest pain that’s usually related to heart disease.

When used to treat stable angina, the typical starting dosage of Lopressor is 100 mg once a day or 50 mg twice a day. The maintenance dosage for this condition ranges from 100 mg daily to 400 mg daily.

Your doctor may recommend a different dosage depending on several factors. These factors include your age or whether you have liver disease. Talk with your doctor about the dosage of Lopressor that’s right for you.

Dosage for reducing risk of death in people who had or may have had a heart attack

Lopressor is approved to help reduce the risk of death in people who’ve had a known or possible heart attack.

For this use, Lopressor treatment is usually started in the hospital. And it’s given in combination with intravenous (IV) metoprolol, which is the active drug in Lopressor. (With IV administration, a drug is given directly into your vein). The dosage for IV metoprolol is different than the dosing for Lopressor tablets.

The starting dosage of Lopressor after you’ve had a known or possible heart attack depends on a few conditions, such as:

  • whether you’ve been given IV metoprolol
  • whether your body is able to tolerate IV metoprolol
  • the amount of time that’s passed since your heart attack
  • your age
  • whether you have liver disease

The usual starting dosage of Lopressor tablets for this condition is 50 mg once every 6 hours starting 15 minutes after your last dose of IV metoprolol. After 48 hours, your Lopressor dosage may be increased to 100 mg twice a day.

Talk with your doctor about the dosage of Lopressor that’s best for you.

What if I miss a dose?

If you miss a dose of Lopressor, take the missed dose as soon as you remember. But if it’s almost time for your next dose, just skip the missed dose and take your next dose at the usual time.

Don’t double your next dose to make up for the missed dose. Doing this may increase your risk of side effects from Lopressor. (For more information about possible side effects, see the “Lopressor side effects” section above.)

To help make sure that you don’t miss a dose, try using a medication reminder. This can include setting an alarm on your phone or downloading a reminder app. A kitchen timer can work, too.

Will I need to use this drug long term?

Lopressor is meant to be used as a long-term treatment for all of its approved uses. If you and your doctor determine that Lopressor is safe and effective for you, you’ll likely take it long term.

The Food and Drug Administration (FDA) approves prescription drugs such as Lopressor to treat certain conditions. Lopressor may also be used off-label for other conditions. Off-label use is when a drug that’s approved to treat one condition is used to treat a different condition.

Below, we describe Lopressor’s approved uses and some off-label ones as well.

Lopressor contains the active drug metoprolol tartrate, which is a type of drug called a beta-blocker. Beta-blockers help lower blood pressure, decrease chest pain, and reduce stress on the heart. For more information, see the “How Lopressor works” section below.

Lopressor for high blood pressure

Lopressor is approved to treat hypertension (high blood pressure). For this purpose, Lopressor may be used alone or in combination with other blood pressure medications.

With high blood pressure, the force of the blood running through your blood vessels consistently stays high. A normal blood pressure for most people is below 120/80 millimeters of mercury (mm Hg). Blood pressure is generally considered high if it’s above 130/80 mmHg.

High blood pressure is called a “silent killer” because most people with it don’t have any symptoms. But possible symptoms of very high blood pressure may include:

  • headache
  • shortness of breath
  • nosebleeds

The best way to know if you have high blood pressure is to check your blood pressure. To do this, you can have your doctor check it, or you can use a blood pressure cuff at your home or local pharmacy. If you use a cuff at your pharmacy, you can ask your pharmacist to help you read and understand your blood pressure results.

Effectiveness for high blood pressure

In clinical studies, Lopressor was effective in lowering high blood pressure when it was used alone or with drugs called thiazide-type diuretics. In addition, Lopressor was found to be as effective at lowering blood pressure as certain other blood pressure medications. Examples of other blood pressure medications that Lopressor was compared with include:

  • methyldopa
  • propranolol
  • medications in a group of drugs called thiazide-type diuretics, such as hydrochlorothiazide

It’s not known for sure how many people’s blood pressure was lowered in these studies. It’s also not known what their average blood pressure levels were before and after treatment. This is because these studies were done several years ago, and these specific numbers weren’t reported in those studies.

Lopressor for chest pain

Lopressor is approved to treat stable angina, which is a type of chest pain that’s usually related to heart disease.

Angina occurs when your heart doesn’t get enough blood flow. Angina often feels like a squeezing, tightness, pressure, or heaviness on your chest. Other symptoms of angina can include:

  • dizziness
  • nausea
  • tiredness
  • shortness of breath
  • sweating

Angina may occur while you’re at rest or while you’re moving around. Angina that occurs while you’re at rest is usually a medical emergency. If you have severe angina that lasts 30 minutes or longer, call 911 or your local emergency number right away.

Effectiveness for chest pain

In clinical studies, Lopressor was effective in treating and preventing chest pain. Clinical studies have also found Lopressor to be as effective as propranolol in treating angina.

It’s not known how severe chest pain was before and after treatment in people who were given these drugs. And the length of time that people had chest pain while using the drugs in these studies isn’t known, either. This is because these studies were done several years ago, and these specific numbers weren’t reported in them.

Lopressor for reducing the risk of death in people who had or may have had a heart attack

Lopressor is approved to reduce the risk of death in people who’ve had a known or possible heart attack. A heart attack happens when blood flow to your heart is blocked by plaque in your arteries. Plaque is usually formed by the buildup of fat, cholesterol, or other substances that flow through your blood vessels.

Symptoms of a heart attack may include:

  • squeezing, tightness, pressure, or pain your chest or arms
  • chest pain that spreads to your jaw, neck, or back
  • shortness of breath
  • sweating
  • sudden dizziness or lightheadedness
  • tiredness
  • nausea
  • belly pain

If you think you may be having a heart attack, call 911 or your local emergency number right away.

Effectiveness in reducing the risk of death in people with heart attack

In clinical studies, Lopressor was effective in lowering the risk of death in people who’ve had or may have had a heart attack.

Also in clinical studies, Lopressor was compared with a placebo (treatment with no active drug). Researchers looked to see if people who took Lopressor after a possible heart attack had a lower risk for death than people who took a placebo. Over a 3-month time period, people who took Lopressor had a 36% lower risk for death than people who took a placebo.

Lopressor for other conditions

In addition to the uses listed above, Lopressor may be used off-label for other uses. Off-label drug use is when a drug that’s approved for one use is used for a different one that’s not approved. And you may wonder if Lopressor is used for certain other conditions. Below is information about other possible uses for Lopressor.

Lopressor for Afib (off-label use)

Lopressor isn’t FDA-approved to treat atrial fibrillation (Afib). (With Afib, you have an abnormal heart rate and rhythm.) However, clinical guidelines recommend that Lopressor be used off-label to manage heart rate in people with Afib.

If you have questions about using Lopressor to treat Afib, talk with your doctor.

Lopressor for tachycardia (off-label use)

Lopressor isn’t approved to treat tachycardia (a heart rate that’s faster than usual). But clinical guidelines recommend using Lopressor to treat a certain type of tachycardia called supraventricular tachycardia (SVT). With SVT, your heart rate is faster than usual, and your heart rhythm is irregular.

If you have questions about using Lopressor to treat tachycardia, talk with your doctor.

Lopressor for migraine (off-label use)

Lopressor is sometimes used off-label to help prevent migraine. The National Headache Foundation and the American Academy of Neurology recommend using Lopressor for this purpose. With migraine, you can have severe headaches as well as other symptoms.

If you’re interested in using Lopressor to help prevent migraine, talk with your doctor.

Lopressor for anxiety (not an off-label use)

Lopressor isn’t approved to treat anxiety. And there aren’t any clinical studies that support using Lopressor off-label to treat this condition.

However, clinical studies have found that beta-blockers other than Lopressor may be effective in treating performance anxiety. (This is anxiety caused by performing in front of others, such as when doing public speaking). For performance anxiety, a beta-blocker called propranolol may be used off-label.

If you have questions about treatment options for anxiety, talk with your doctor.

Lopressor and children

Lopressor hasn’t been studied in children. It isn’t known if Lopressor is safe or effective for use in children.

Lopressor is approved for use in adults to:

When used to treat high blood pressure, Lopressor may be used in combination with other blood pressure medications, such as diuretics.

And when used in people who had or may have had a heart attack, Lopressor can be given alone or in combination with intravenous (IV) metoprolol. (Metoprolol tartrate is the active drug in Lopressor.) With IV administration, a drug is given directly into your vein.

In addition, if you have multiple health conditions, your doctor may recommend that you take other medications with Lopressor.

Talk with your doctor about the best treatment options for your condition.

You may wonder how Lopressor compares with other medications that are prescribed for similar uses. Here we look at how Lopressor and Toprol XL are alike and different.

Ingredients

Both Lopressor and Toprol XL contain the same active drug: metoprolol. And these medications both belong to a group of drugs called beta-blockers.

However, Lopressor and Toprol XL each contain a different salt form of metoprolol. (Medications are sometimes manufactured as salt forms to help them be absorbed and released into your body). Lopressor contains the salt form metoprolol tartrate, while Toprol XL contains the salt form metoprolol succinate.

Uses

Both Lopressor and Toprol XL are approved for use in adults to:

Lopressor is also approved to lower the risk of death in adults who may have had a heart attack. And Toprol XL is also approved to treat certain types of heart failure in adults.

Drug forms and administration

Both Lopressor and Toprol XL come as tablets that are taken by mouth. You’ll likely take Lopressor once or twice a day with food. Toprol XL, on the other hand, can be taken once a day with or without food.

Side effects and risks

Lopressor and Toprol XL both contain metoprolol. Therefore, these medications can cause very similar side effects, but some different ones as well. Below are examples of these side effects.

Mild side effects

These lists contain up to 10 of the most common mild side effects that can occur with each drug, or with both Lopressor and Toprol XL (when taken individually).

Serious side effects

These lists contain examples of serious side effects that can occur with Lopressor or with both drugs (when taken individually).

Effectiveness

Lopressor and Toprol XL have different approved uses, but they’re both used to treat high blood pressure and chest pain.

These drugs haven’t been directly compared in clinical studies. But separate studies have found both Lopressor and Toprol XL to be effective in treating these conditions.

Costs

Lopressor and Toprol XL are both brand-name drugs. Lopressor is also available in a generic form called metoprolol tartrate, and Toprol XL is available in a generic form called metoprolol succinate. Brand-name medications usually cost more than generics.

According to estimates on GoodRx.com, Lopressor costs significantly more than Toprol XL. The actual price you’ll pay for either drug depends on your insurance plan, your location, and the pharmacy you use.

Lopressor comes as tablets that are taken by mouth. You should take Lopressor according to your doctor or healthcare provider’s instructions.

When to take

You’ll likely take Lopressor once or twice a day. You can take Lopressor anytime, but you should try to take it at about the same time each day.

To help make sure that you don’t miss a dose, try using a medication reminder. This can include setting an alarm on your phone or downloading a reminder app. A kitchen timer can work, too.

Taking Lopressor with food

Lopressor should be taken with food. You can take it with a meal or shortly after eating.

Can Lopressor be crushed, split, or chewed?

You shouldn’t crush or chew Lopressor. However, you can cut Lopressor tablets in half.

Lopressor comes in two strengths: 50 milligrams (mg) and 100 mg. So, if your doctor prescribes a 25-mg dose of Lopressor, you can cut 50-mg tablets in half. Then, you would take one of the half tablets for your dose.

And if your doctor prescribes a 12.5-mg dose of Lopressor, you can cut 50-mg tablets into fourths. Then, you would take one-fourth of a tablet for your dose.

It may not be safe to use Lopressor while you’re breastfeeding. Small amounts of Lopressor do pass into human breast milk, which means the drug may be passed to a child who’s breastfed. But it’s not known what effect Lopressor may have on a child who’s breastfed.

If you’re breastfeeding or planning to breastfeed while using Lopressor, talk with your doctor. They can discuss with you the possible risks and benefits of using this drug.

It isn’t known if Lopressor is safe to use during pregnancy. Lopressor hasn’t been studied in pregnant women.

If you’re pregnant or planning a pregnancy, talk with your doctor about using Lopressor. They can discuss with you the risks and benefits of taking this drug.

Lopressor and fertility

It isn’t known whether Lopressor can affect your fertility (ability to conceive or cause conception).

Animal studies have shown that Lopressor may impact a male’s ability to produce sperm, which could affect fertility. However, Lopressor’s effect on fertility in humans hasn’t been studied. And animal studies don’t always predict what will happen in humans.

If you and your partner are planning a pregnancy or have concerns about fertility, talk with your doctor before starting Lopressor.

It’s not known if Lopressor is safe to take during pregnancy. If you’re sexually active and you or your partner can become pregnant, talk with your doctor about your birth control needs while you’re using Lopressor.

For more information about taking Lopressor during pregnancy, see the “Lopressor and pregnancy” section above.

Other drugs are available that can treat your conditions. Some may be a better fit for you than others. If you’re interested in finding an alternative to Lopressor, talk with your doctor. They can tell you about other medications that may work well for you.

Note: Some of the drugs listed here are used off-label to treat these specific conditions. Off-label use is when a drug that’s approved to treat one condition is used to treat a different condition.

Alternatives for high blood pressure

Examples of other drugs that may be used to treat high blood pressure include:

Alternatives for chest pain

Examples of other drugs that may be used to treat stable angina (a type of chest pain) include:

  • nitrates, such as:
    • isosorbide dinitrate (Dilatrate-SR)
    • isosorbide mononitrate (Imdur)
    • nitroglycerin (Nitro-Dur)
  • calcium channel blockers, such as:
    • amlodipine (Norvasc)
    • diltiazem (Cardizem)
  • beta-blockers, other than Lopressor, such as:
    • extended-release metoprolol succinate (Toprol XL)
  • ranolazine (Ranexa)

Alternatives for reducing the risk of death in people who had or may have had a heart attack

Other drugs may be used to reduce the risk of death in people who have had or may have had a heart attack. Examples include:

You may wonder how Lopressor compares with other medications that are prescribed for similar uses. Here we look at how Lopressor and labetalol are alike and different.

Ingredients

Lopressor contains the active drug metoprolol tartrate. Labetalol is an active drug ingredient that’s available as a generic medication. (A generic medication is an exact copy of the active drug found in a brand-name medication.)

Lopressor and labetalol both belong to a group of drugs called beta-blockers.

Uses

Lopressor and labetalol are both approved to treat high blood pressure in adults. In addition, Lopressor is approved for use in adults to:

Drug forms and administration

Lopressor and labetalol come as tablets that are taken by mouth. Lopressor is typically taken once or twice daily with food. Labetalol, on the other hand, is generally taken once daily with or without food.

Side effects and risks

Lopressor and labetalol are both in a group of drugs called beta-blockers. Therefore, these medications can cause very similar side effects, but some different ones as well. Below are examples of these side effects.

Mild side effects

These lists contain up to 10 of the most common mild side effects that can occur with each drug, or with both Lopressor and labetalol (when taken individually).

Serious side effects

These lists contain examples of serious side effects that can occur with Lopressor, with labetalol, or with both drugs (when taken individually).

  • Can occur with Lopressor:
    • heart block (having your heart beat too slowly or in an irregular rhythm, and possibly stop beating for several seconds)
    • bronchospasm (tightening or spasm of the muscles in your airway)
    • cardiogenic shock, which occurs when your heart can’t pump enough blood to other organs in your body
  • Can occur with labetalol:
    • postural hypotension (a decrease in your blood pressure when standing)
  • Can occur with both Lopressor and labetalol:
    • edema (swelling)

Effectiveness

Lopressor and labetalol have different approved uses, but they’re both used to treat high blood pressure.

These drugs haven’t been directly compared in clinical studies. But separate studies have found both Lopressor and labetalol to be effective in treating high blood pressure.

Costs

According to estimates on GoodRx.com, Lopressor costs significantly more than labetalol. The actual price you’ll pay for either drug depends on your insurance plan, your location, and the pharmacy you use.

Lopressor is a brand-name drug. Labetalol is a generic drug. Brand-name medications usually cost more than generics.

Lopressor is approved for use in adults to:

Lopressor contains the active drug metoprolol tartrate. It’s is a type of drug called a beta-blocker.

What do beta-blockers do?

Beta-blockers work by preventing the hormones epinephrine and norepinephrine from attaching to beta receptors in your body. Beta receptors are proteins on the surface of cells in your heart, blood vessels, and lungs. They enable substances, such as the molecules of a drug, to attach to the protein and relay a chemical message.

Lopressor specifically works on beta-1 receptors. These receptors are located in your heart. Because Lopressor works specifically on beta-1 receptors, it’s less likely to affect beta-2 receptors, which are located in other parts of your body outside of your heart. This helps to reduce possible side effects related to Lopressor treatment.

Typically, when epinephrine and norepinephrine attach to beta-1 receptors, the following changes occur in your body:

  • heart rate increases
  • blood pressure increases
  • electrical activity of the heart increases
  • heart muscles squeeze more forcefully

How does Lopressor help the heart?

Over time, the effects of epinephrine and norepinephrine can make your heart muscles work harder and require more oxygen.

If your heart isn’t getting enough oxygen, you can develop angina (a type of chest pain). And if you have high blood pressure or may have had a heart attack, your heart is also working harder and requiring more oxygen.

By blocking epinephrine and norepinephrine from attaching to beta-1 receptors, Lopressor helps to:

  • lower blood pressure
  • decrease chest pain
  • reduce stress on your heart

How long does it take for Lopressor to work?

The amount of time it takes for Lopressor to work can depend on several things. These include:

  • your age
  • the dosage of Lopressor you’re taking
  • the condition you’re using Lopressor to treat

In general, it may take up to 1 week for Lopressor to improve your blood pressure or chest pain. But remember, most people with high blood pressure don’t have any symptoms. So, even if you don’t “feel” your blood pressure lowering after you take Lopressor, it’s still happening.

Also, you may not notice any effects of Lopressor in reducing your risk for death after a heart attack. This is because for this purpose, the drug is helping to prevent death rather than treating certain symptoms you may have.

Your doctor will likely monitor your condition closely during the first several weeks of Lopressor treatment. If your condition isn’t improving during this time, your doctor may increase your dosage of the drug. (For more information on dosing, see the “Lopressor dosage” section above.)

As with all medications, the cost of Lopressor can vary. To find current prices for Lopressor tablets in your area, check out GoodRx.com.

The cost you find on GoodRx.com is what you may pay without insurance. The actual price you’ll pay depends on your insurance plan, your location, and the pharmacy you use.

Before approving coverage for Lopressor, your insurance company may require you to get prior authorization. This means that your doctor and insurance company will need to communicate about your prescription before the insurance company will cover the drug. The insurance company will review the prior authorization request and decide if the drug will be covered.

If you’re not sure if you’ll need to get prior authorization for Lopressor, contact your insurance company.

Financial and insurance assistance

If you need financial support to pay for Lopressor, help may be available.

MedicineAssistanceTool.org offers programs that may help lower the cost of Lopressor. For more information and to find out if you’re eligible for support, visit their website or talk with your doctor or pharmacist.

Generic version

Lopressor is available in a generic form called metoprolol tartrate. A generic drug is an exact copy of the active drug in a brand-name medication. The generic is considered to be as safe and effective as the original drug. And generics tend to cost less than brand-name drugs. To find out how the cost of metoprolol tartrate drug compares to the cost of Lopressor, visit GoodRx.com.

If your doctor has prescribed Lopressor and you’re interested in using metoprolol tartrate instead, talk with your doctor. They may have a preference for one version or the other. You’ll also need to check your insurance plan, as it may only cover one or the other.

There aren’t any known interactions between Lopressor and alcohol.

However, drinking alcohol in large amounts can increase your blood pressure. Ask your doctor if you should avoid drinking alcohol or if there’s an amount that’s safe for you to drink while you’re taking Lopressor.

Also, keep in mind that drinking too much can cause dizziness, drowsiness, or problems with your balance. And low blood pressure, which is a side effect of Lopressor, may also cause dizziness. So, drinking alcohol while taking Lopressor could increase your risk for falls and other accidents. (For more information about low blood pressure, see the “Lopressor side effects” section above.)

Lopressor can interact with several other medications. It can also interact with certain supplements as well as certain foods.

Different interactions can cause different effects. For instance, some interactions can interfere with how well a drug works. Other interactions can increase side effects or make them more severe.

Lopressor and other medications

Below are lists of medications that can interact with Lopressor. These lists do not contain all the drugs that may interact with Lopressor.

Before taking Lopressor, talk with your doctor and pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

Lopressor and medications that decrease epinephrine and norepinephrine

Lopressor may interact with medications that decrease levels of epinephrine and norepinephrine in your body. Medications that reduce the levels of these hormones can cause serious side effects, including:

Bradycardia and low blood pressure are also serious side effects of Lopressor. So, taking these medications together can increase your risk for the side effects even more. (For more information, see the “Lopressor side effects” section above.)

Examples of medications that can decrease your levels of epinephrine and norepinephrine include:

Before you take Lopressor, be sure to tell your doctor about other medications you’re taking. Your doctor can recommend whether it’s safe for you to take Lopressor.

Lopressor and digoxin

Taking Lopressor with digoxin can increase your risk for bradycardia (heart rate that’s slower than normal). Digoxin is used to treat certain heart conditions, including atrial fibrillation (Afib) and heart failure.

If you take digoxin, tell your doctor before taking Lopressor. They may want to monitor you more closely than usual during treatment. Or they may recommend different treatment options for you.

Lopressor and calcium channel blockers

Taking Lopressor with medications called calcium channel blockers can increase your risk of bradycardia (heart rate that’s slower than normal). Calcium channel blockers are used to treat high blood pressure.

Examples of calcium channel blockers include:

If you take any of the medications listed above, tell your doctor before starting Lopressor. Your doctor can recommend whether it’s safe for you to take Lopressor.

Lopressor and certain medications that affect the breakdown of Lopressor

You shouldn’t take Lopressor with certain drugs that affect how your body metabolizes (breaks down) Lopressor. Below we describe these types of drugs.

Lopressor and CYP2D6 inhibitors

CYP2D6 inhibitors are a group of drugs that work by inhibiting (blocking) the action of the CYP2D6 enzyme. Your body uses the CYP2D6 enzyme to break down Lopressor.

Medications that block CYP2D6’s action can raise the level of Lopressor in your blood. And this increases your risk for side effects from Lopressor. (To learn more about side effects, see the “Lopressor side effects” section above.)

Examples of CYP2D6 inhibitors include:

If you use any of the drugs listed above, talk with your doctor before taking Lopressor. They may adjust your dose of Lopressor or monitor your condition more closely than usual during treatment.

Lopressor and hydralazine

Hydralazine, which is used to treat high blood pressure, can slow the breakdown of Lopressor in your body. This can increase your blood levels of Lopressor and increase your risk for side effects from the drug. (To learn more about side effects, see the “Lopressor side effects” section above.)

Before you start taking Lopressor, tell your doctor if you take hydralazine. They may want to monitor your condition more closely than usual during treatment. Or they may adjust your Lopressor dosage.

Lopressor and alpha-blockers

Taking Lopressor with medications called alpha-blockers can increase your risk for low blood pressure. Alpha-blockers are used to treat high blood pressure.

Clonidine is an example of an alpha-blocker. If you take Lopressor with clonidine, you should stop taking Lopressor for several days before you stop taking clonidine. This is because taking Lopressor with clonidine can increase your risk for high blood pressure if you stop taking clonidine.

However, you shouldn’t stop taking Lopressor without first talking with your doctor. Suddenly stopping Lopressor can cause serious heart problems. (For more information, see the “Common questions about Lopressor” section below.)

Examples of alpha blockers other than clonidine include:

If you take any of these medications, tell your doctor before starting Lopressor. Your doctor can recommend whether it’s safe for you to take Lopressor.

Lopressor and ergot alkaloids

Ergot alkaloids are a group of drugs that can be used to treat severe headaches. They work by narrowing your blood vessels. Taking Lopressor with ergot alkaloids can cause your blood vessels to narrow even more, causing pain in your hands and feet.

Examples of ergot alkaloids include:

If you use any of these drugs, talk with your doctor before taking Lopressor. They may suggest different treatment options for you.

Lopressor and dipyridamole

Dipyridamole is a drug that may be injected into your bloodstream to test the flow of blood through your heart. Dipyridamole can cause changes in your blood pressure and heart rate. And taking dipyridamole with Lopressor can affect your blood pressure or heart rate even more.

Before receiving dipyridamole for any medical tests, be sure to tell your doctor if you’re taking Lopressor. They may want to stop your Lopressor treatment before you receive a dipyridamole injection.

Lopressor and herbs and supplements

There aren’t any herbs or supplements that have been specifically reported to interact with Lopressor. However, you should still check with your doctor or pharmacist before using any of these products while taking Lopressor.

Lopressor and foods

There aren’t any foods that have been specifically reported to interact with Lopressor. If you have any questions about eating certain foods with Lopressor, talk with your doctor.

Using more than the recommended dosage of Lopressor can lead to serious side effects. Do not use more Lopressor than your doctor recommends.

Overdose symptoms

Symptoms of an overdose can include:

What to do in case of overdose

If you think you’ve taken too much of this drug, call your doctor. You can also call the American Association of Poison Control Centers at 800-222-1222 or use their online tool. But if your symptoms are severe, call 911 or your local emergency number, or go to the nearest emergency room right away.

Here are answers to some frequently asked questions about Lopressor.

Is it safe to stop taking Lopressor?

It isn’t safe to suddenly stop taking Lopressor without first telling your doctor. Suddenly stopping Lopressor can cause serious heart problems, including:

Suddenly stopping Lopressor can also cause a condition called thyroid storm in people who have hyperthyroidism. (With hyperthyroidism, you have an overactive thyroid gland.)

If your doctor recommends that you stop taking Lopressor, they will probably gradually lower your dosage of the drug over a couple of weeks. They will also monitor you closely for worsening heart problems.

Can I take Lopressor if I’m going to have surgery?

Yes, you most likely can. Taking Lopressor before surgery may increase your risk for unstable blood pressure while you’re under anesthesia during surgery. However, in some cases, stopping Lopressor for surgery can be riskier than continuing to use it.

Talk with your doctor if you have questions using Lopressor around the time of surgery. Your doctor can discuss with you the risks and benefits of continuing to use this medication.

If I have diabetes, can I use Lopressor?

Maybe. Lopressor may hide certain symptoms of low blood sugar. And certain diabetes drugs increase your risk for low blood sugar. If you’re taking Lopressor with diabetes drugs, you might not notice all the possible symptoms of hypoglycemia (low blood sugar).

For example, Lopressor may mask the symptom of increased heart rate. But other symptoms of low blood sugar, such as sweating or dizziness, aren’t affected by Lopressor.

If you have diabetes, talk with your doctor before using Lopressor. They may want to monitor your condition more closely during treatment. They may suggest ways to monitor your blood sugar level while you’re using Lopressor. Or they may switch you to a different beta-blocker that won’t affect your blood sugar levels.

Can I take Lopressor if I have liver or kidney problems?

Yes, in general, you should be able to.

There aren’t any known issues with taking Lopressor if you have kidney problems.

However, if you have liver problems, your doctor may start you on a dosage of Lopressor that’s lower than the typical starting dosage. Then, they may increase your dosage slowly over time. This allows your doctor to make sure the drug is treating your condition without causing bothersome or harmful side effects.

If you have liver or kidney problems, talk with your doctor about using Lopressor. They can recommend whether this drug is a good treatment option for you.

Can I use Lopressor if I have asthma or COPD?

Beta-blockers may cause breathing problems such as shortness of breath, wheezing, or bronchospasm. (Lopressor belongs to a group of drugs called beta-blockers.)

Beta-blockers work by preventing the hormones epinephrine and norepinephrine from attaching to beta receptors in your body. Beta receptors are proteins on the surface of cells in your heart, blood vessels, and lungs. They enable substances, such as the molecules of a drug, to attach to the protein and relay a chemical message.

If you have asthma or chronic obstructive pulmonary disease (COPD), beta-blockers might make it difficult for you to manage your breathing problems.

However, because Lopressor acts on beta receptors mostly in the heart and blood vessels and not your lungs, it’s a called a cardioselective beta-blocker. This means that Lopressor may be used safely in people with asthma or COPD whose blood pressure hasn’t improved after using other blood pressure medications. In this situation, their doctor may recommend taking a very low dose of Lopressor.

Be sure to tell your doctor if you have asthma or COPD before you start using Lopressor. Your doctor can recommend whether it’s safe for you to take Lopressor.

Will I be able to drive after starting Lopressor treatment?

Yes, but maybe not right away. To be safe, you shouldn’t drive after starting Lopressor treatment until you know how the drug affects you. This is because Lopressor may cause some people to feel very tired or lightheaded. And these side effects could make driving dangerous for you and others.

Talk with your doctor about any side effects that you have after starting Lopressor. They can help you decide when it’s safe for you to drive while you’re using this medication.

Before taking Lopressor, talk with your doctor about your health history. Lopressor may not be right for you if you have certain medical conditions or other factors affecting your health. These include:

  • Surgery. Taking Lopressor before surgery may increase your risk for unstable blood pressure while you’re under anesthesia during surgery. Be sure that your doctor knows you’re taking Lopressor before you have any surgeries. Your doctor may want to talk with you about the risks and benefits of continuing to use Lopressor around the time of your procedure. (For more information, see the “Common questions about Lopressor” section above.)
  • Asthma or COPD. Lopressor and other beta blockers may cause breathing problems such as shortness of breath, wheezing, or bronchospasm in people with asthma or chronic obstructive pulmonary disease (COPD). And this can worsen symptoms of asthma or COPD. Be sure to tell your doctor if you have asthma or COPD before starting Lopressor.
  • Diabetes. Lopressor may hide certain symptoms of low blood sugar, such as increased heart rate. If you have diabetes, you may be taking diabetes drugs that increase your risk for low blood sugar. Talk with your doctor before using Lopressor. They may want to monitor your condition more closely than usual. Or they may suggest ways to monitor your blood sugar while using Lopressor.
  • Pheochromocytoma. If you have pheochromocytoma (a type of tumor on your adrenal gland), taking Lopressor may cause your blood pressure to increase. Tell your doctor if you have pheochromocytoma before starting treatment with Lopressor. They may want to prescribe a different type of drug called an alpha-blocker for you before you start Lopressor. Taking an alpha-blocker with Lopressor can help lower your risk for increased blood pressure.
  • Hyperthyroidism. Lopressor may hide certain symptoms of hyperthyroidism. If you have hyperthyroidism, talk with your doctor before starting or stopping Lopressor. They may want to monitor your condition more closely during treatment. If you’re stopping Lopressor, your doctor may recommend slowly decreasing your Lopressor doses over time to lower your risk of thyroid storm.
  • Heart problems. Tell your doctor if you have certain heart problems before starting Lopressor. These heart problems may include heart block, irregular heartbeat, slow heart rate, or low blood pressure. Taking Lopressor while you have these heart problems can increase your risk of an even slower heart rate. Be sure to tell your doctor about any heart conditions you have before starting treatment with Lopressor.
  • Allergic reaction. If you’ve had an allergic reaction to Lopressor or any of its ingredients, you shouldn’t take Lopressor. Ask your doctor what other medications are better options for you. And if you’re unsure of your medication allergies, talk with your doctor.
  • Pregnancy. It isn’t known if Lopressor is safe to use during pregnancy. For more information, please see the “Lopressor and pregnancy” section above.
  • Breastfeeding. It may not be safe to use Lopressor while breastfeeding. For more information, please see the “Lopressor and breastfeeding” section above.

Note: For more information about the potential negative effects of Lopressor, see the “Lopressor side effects” section above.

When you get Lopressor from the pharmacy, the pharmacist will add an expiration date to the label on the bottle. This date is typically 1 year from the date they dispensed the medication.

The expiration date helps guarantee that the medication is effective during this time. The current stance of the Food and Drug Administration (FDA) is to avoid using expired medications. If you have unused medication that has gone past the expiration date, talk to your pharmacist about whether you might still be able to use it.

Storage

How long a medication remains good can depend on many factors, including how and where you store the medication.

Lopressor tablets should be stored at room temperature (77°F/25°C) in a tightly sealed container away from light. Avoid storing this medication in areas where it could get damp or wet, such as in bathrooms.

For short periods of time, Lopressor can be stored at a temperature from 59°F to 86°F (15°C to 30°C).

Disposal

If you no longer need to take Lopressor and have leftover medication, it’s important to dispose of it safely. This helps prevent others, including children and pets, from taking the drug by accident. It also helps keep the drug from harming the environment.

This article provides several useful tips on medication disposal. You can also ask your pharmacist for information on how to dispose of your medication.

The following information is provided for clinicians and other healthcare professionals.

Indications

Lopressor is indicated for the treatment of hypertension and angina pectoris, and to reduce mortality after a known or suspected myocardial infarction in people who are hemodynamically stable.

Administration

Lopressor is taken by mouth, with food or immediately after a meal.

Mechanism of action

Lopressor is a beta-blocker that is selective for beta-1 receptors on cardiac blood vessels. Lopressor prevents epinephrine and norepinephrine from binding to beta-1 receptors, thereby decreasing heart rate, blood pressure, and cardiac output.

Pharmacokinetics and metabolism

Lopressor has 50% oral bioavailability and is hepatically metabolized via CYP2D6. Its approximate half-life is 3 to 4 hours (7 to 9 hours in poor metabolizers). It is excreted primarily through the urine.

Contraindications

When treating hypertension or angina, Lopressor is contraindicated under the following conditions:

  • sinus bradycardia
  • second- or third-degree heart block
  • cardiogenic shock
  • cardiac failure
  • sick-sinus syndrome
  • peripheral arterial circulatory disorders
  • hypersensitivity to other beta-blockers

When used to decrease the risk of death after a myocardial infarction, Lopressor is contraindicated under the following conditions:

  • heart rate less than 45 beats per minute
  • first-degree heart block with PR interval ≥0.24 seconds
  • second- and third-degree heart block
  • systolic blood pressure <100 mm Hg
  • moderate-to-severe cardiac failure

Storage

Lopressor tablets should be stored at room temperature (77°F/25°C) and protected from heat and moisture. Temperature excursions are permitted from 59°F to 86°F (15°C to 30°C).

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.