If you have a heart attack, your doctor may give you metoprolol tartrate (Lopressor). This drug can prevent another heart attack from occurring. However, you should be careful not to confuse it with metoprolol succinate (Toprol-XL).

While the two drugs share the same first word and both treat heart-related issues, metoprolol succinate doesn’t prevent or treat a heart attack in people who’ve already had a heart attack. Learn more about the similarities and differences between these two drugs.

Metoprolol tartrate and metoprolol succinate contain the same active medication: metoprolol. However, they contain different salt forms. These salt forms, tartrate and succinate, are approved by the U.S. Food and Drug Administration (FDA) for different conditions. Both medications belong to a class of drugs called beta-blockers, which work by relaxing your blood vessels and slowing down your heart rate.

Metoprolol tartrate is used to treat high blood pressure, chest pain due to heart disease, or heart attack. It’s also used to prevent heart attacks in people who’ve had a heart attack or other heart disease.

Like metoprolol tartrate, metoprolol succinate is used to treat high blood pressure and chest pain related to heart disease. It’s also used to treat heart failure. However, metoprolol succinate shouldn’t be used to prevent heart attacks.

Used forMetoprolol tartrateMetoprolol succinate
High blood pressure XX
Chest pain related to heart diseaseXX
Heart attack preventionX
Unstable angina X
ArrhythmiaX
Heart failure X

Although they both treat high blood pressure and chest pain, these drugs aren’t interchangeable. They’re dosed differently.

Metoprolol succinate comes as an extended-release oral tablet. When a drug is extended release, it means it releases into your body slowly. You usually take it once per day.

Metoprolol tartrate is available as an immediate-release oral tablet. It doesn’t stay in your body as long as metoprolol succinate does, so you must take it multiple times per day. This drug also comes as a solution for injection that’s used to treat unstable angina and arrhythmia. A healthcare provider gives you this injection, you don’t give it to yourself.

The table below summarizes other features of these medications.

Generic nameMetoprolol tartrateMetoprolol succinate
What’s the brand-name version?LopressorToprol-XL
Is a generic version available?YesYes
What form does it come in?Immediate-release oral tablet; injectable solutionExtended-release oral tablet
What strengths does it come in?Oral tablet: 25 mg, 37.5 mg, 50 mg, 75 mg, 100 mg Injectable solution: 5 mg/5 ml25 mg, 50 mg, 100 mg, 200 mg
What’s the typical length of treatment?Long-termLong-term
How do I store it?Store at room temperature from 59°F (15°C) to 86°F (30°C)Store at room temperature from 59°F (15°C) to 86°F (30°C)

Metoprolol tartrate and metoprolol succinate are both available as generic drugs. Both medications are commonly prescribed and should be available in most pharmacies. In most cases, generic forms of drugs cost less than their brand-name versions.

Metoprolol succinate costs about twice as much as metoprolol tartrate if you’re paying for the drug out of pocket without assistance from your health insurance plan. The most current price estimates are available at GoodRx.com. Metoprolol succinate may cost between $14 and $44 for a one-month supply, while metoprolol tartrate may cost anywhere from $4 to $18 for a one-month supply.

If you have prescription coverage through your health insurance plan, the price you pay for these drugs may be lower.

Because both drugs contain the same active medication, they cause similar side effects. The table below lists examples of side effects of metoprolol tartrate and metoprolol succinate.

Common side effectsMetoprolol tartrateMetoprolol succinate
tirednessXX
dizzinessXX
depressionXX
diarrheaXX
slower-than-normal heart rateXX
rashXX
Serious side effectsMetoprolol tartrateMetoprolol succinate
very slow heart rateXX
shortness of breath or wheezingXX
low blood pressureX
worsening chest pain X
worsening heart failure X

Metoprolol tartrate and metoprolol succinate both carry a boxed warning, the most serious warning from the FDA. The FDA warns that either drug may cause worse chest pain or a heart attack if you stop taking it suddenly. This risk is higher in people with heart disease.

If you need to stop taking either drug, your doctor will slowly lower your dosage over one to two weeks.

Both drugs share similar drug interactions. Make sure you tell your doctor about all prescription and over-the-counter drugs, supplements, and herbs you take before you start treatment with a new medication.

The following medications may interact with metoprolol tartrate or metoprolol succinate.

Medications to control blood pressure:

  • reserpine (Serpasil)
  • hydralazine
  • the antihypertensive drugs guanethidine, betanidine, and alpha-methyldopa

Medications to treat heart disease:

Medications to treat mental health conditions:

Other medications:

If you have certain health issues, you should tell your doctor about them before you start treatment with metoprolol tartrate or metoprolol succinate. If you’re already taking either drug, you should also tell your doctor if you have plans to have surgery.

Both drugs carry warnings for the same health problems. Discuss the following medical conditions with your doctor before taking metoprolol tartrate or metoprolol succinate:

If your doctor prescribes metoprolol tartrate or metoprolol succinate, it’s important to be sure which drug you’re taking. One drug cannot be substituted for the other.

Both drugs come in different forms, are approved for different uses, and cause slightly different side effects. Work with your doctor to decide which drug is best for you.