Generic Name is metoprolol tartrate (ma TOE proe lol / TAR trayt) and Brand Name is Lopressor (loe PRES sor)

Generic Name for extended release is metoprolol succinate (ma TOE proe lol / SUK sin ate) and Brand Name is Toprol-XL (TOE prawl ‘X’ ‘L’)


Metoprolol is available as metoprolol tartrate (Lopressor), an immediate release tablet and metoprolol succinate (Toprol-XL), a long acting, extended release tablet. Metoprolol belongs to the group of heart/blood pressure drugs known as beta-blockers. That means they work partly by blunting the action of adrenaline, the body’s natural fight-or-flight chemical. People normally respond to stressful situations with a rapid pulse, a pounding heart and an increase in blood pressure. Metoprolol (Lopressor, Toprol-XL) helps block such reactions by slowing the heart rate and relaxing the blood vessels so the heart does not have to pump as hard.

Metoprolol (Lopressor, Toprol-XL) is usually prescribed for high blood pressure, chest pain, heart attacks, and prevention of a second heart attack. The extended release metoprolol (Toprol-XL) is also used in combination with other medications to treat heart failure. Although the FDA has not specifically approved its use for other purposes, doctors sometimes prescribe metoprolol (Lopressor, Toprol-XL) to treat irregular heart rhythms or tremors, and to prevent migraine headaches.

People’s Pharmacy Perspective

Beta blockers have been around a long time and generally have low cost generics available. One word of caution, however: We have heard from a significant number of people that not all generic Toprol XL (metoprolol succinate) is created equal. Some people have seen their blood pressure skyrocket while others have developed irregular heart rhythms. See their stories.

Beta blockers such as metoprolol should probably not be considered as first-line treatments for high blood pressure (1,2). British hypertension experts reserve beta blockers almost as a last resort, when other blood pressure medicines don’t work (3). Since beta blockers have the potential to cause numerous side effects (and negatively impact blood fats), we agree that they should be used cautiously.

Beta blockers are valuable for managing chest pain and preventing another heart attack after someone has already had one. They may also be valuable when adequate blood pressure control is not achieved with other classes of drugs. You and your physician will need to decide if the benefits outweigh the risks.

Be certain to consult a physician about your health, especially with regard to any signs or symptoms that may require diagnosis or medical attention. Information provided is not a substitute for the medical advice or care of a physician or other health care professional.

Special Precautions

DO NOT stop taking metoprolol (Lopressor, Toprol-XL) suddenly without first talking to your doctor. Stopping abruptly may trigger potentially fatal heart problems.

Pregnancy/Breastfeeding: Consult your doctor if you are pregnant or planning a pregnancy, or will be breastfeeding while taking this medication.

Metoprolol (Lopressor, Toprol-XL) is not recommended for some people: People who have had an allergic reaction to beta-blockers, metoprolol (Lopressor, Toprol-XL) or its components and people with certain serious heart problems, such as heart rates less than 45 beats per minute (for heart attack patients) or abnormal heart rhythms. The medication could occasionally lead to serious cardiac complications for these individuals. Note that only metoprolol succinate (Toprol-XL), the extended release tablet, is indicated for heart failure. Metoprolol tartrate (Lopressor) is not recommended for people with heart failure.

Some people must be very carefully monitored if they take beta-blockers such as metoprolol (Lopressor, Toprol-XL). In general, people with heart failure must be extremely cautious if prescribed beta blockers because the medicine could lead to cardiac complications. Those prescribed metoprolol succinate (Toprol-XL) are no exception; other medications they are on may need to be adjusted, and most importantly, they must be closely monitored for worsening of their heart condition.

Asthmatics and patients with other respiratory problems are especially vulnerable, as these drugs can make breathing worse. Metoprolol (Lopressor, Toprol-XL) may be a little better than other beta-blockers in this regard, but monitor your breathing carefully. Diabetics should inform their physicians if being prescribed metoprolol (Lopressor, Toprol-XL) since the medication may mask the signs of low blood sugar levels.

People with a history of depression should inform their doctors to ensure both their depression and beta-blocker therapy is well managed. Metoprolol (Lopressor, Toprol-XL) is more likely to affect the nervous system than others in its class and may contribute to depression. People with a thyroid disorder should also be carefully monitored as metoprolol (Lopressor, Toprol-XL) may mask signs of an overly active thyroid. Lastly, people with liver impairments may also need to be very carefully monitored.

Be certain to inform your doctor of any other conditions you may have. This information may affect your dose, whether you should even take this medication, or require you to take special tests during treatment.

Taking the Medicine

Metoprolol (Lopressor, Toprol-XL) is best absorbed when taken with or right after meals. Food may reduce the risk of digestive tract upset and taking the drug at roughly the same time each day allows your body to maintain a constant level of the medication in your blood stream. Metoprolol (Lopressor, Toprol-XL) should be taken with a full glass of water. Avoid alcohol while on metoprolol (Lopressor, Toprol-XL) because it increases drowsiness and dizziness, and do not take calcium supplements or antacids within two hours of metoprolol because they may reduce absorption.

If surgery is scheduled, ask your surgeon and anesthesiologist to see if your beta blocker dose will need to be adjusted. Never stop taking metoprolol (Lopressor, Toprol-XL) suddenly. Your doctor must reduce your dose gradually to prevent serious heart problems.

Common Side Effects

• anxiety, nervousness

• sleep problems (insomnia)

• tired feeling

• vomiting

• decreased sex drive, impotence, or difficulty having an orgasm

• arthritis

The medicine may also have a negative effect on cholesterol and other blood fats, so a lipid test before treatment and periodically thereafter would be prudent.

Serious Side Effects

Obtain emergency medical care if you experience these signs of a potential allergic reaction:

• breathing difficulties

• swelling in your face, lips, tongue, or throat

Call your doctor promptly if you experience any of these serious side effects:

• feeling light-headed, fainting

• worsening depression, memory loss or mood swings

• wheezing, worsening asthma

• feeling short of breath, even with mild exertion

• extra-slow or uneven heartbeats

• stomach upset, low fever, lack of appetite, dark urine, pale-colored stools, jaundice (yellowing of the skin or eyes)

• swelling of your ankles or feet

• cold feeling in your hands and feet

• hives, itchiness, rash

There may be other s
ide effects not listed here. Talk to your doctor if your condition worsens and ask about any side effect that seems unusual or is especially bothersome. Never stop taking any beta blocker medication abruptly unless you are under very close medical supervision. Angina or a heart attack could occur.

Drug Interactions

• Catapres (clonidine): If you are on both blood pressure medications, do not suddenly discontinue either medicine, as the increase in blood pressure could be life threatening.

• Prazosin (Minipress) is more likely to cause fainting problems when combined with Lopressor.

• Hydralazine (Apresoline), propafenone (Rythmol), quinidine, and calcium channel blockers ([verapamil (Calan)], [diltiazem (Cardiem)]): These are also heart/blood pressure medications, which would have increased effects if given together with metoprolol (Lopressor, Toprol-XL). Taking beta-blockers with calcium channel blockers is generally not advised since the combined effects may lead to serious heart problems. If they must be taken together, the dose of one or both medications may need to be reduced and cardiac function should be carefully monitored.

• Propylthiouracil or methimazole (Tapazole), insulins: Beta-blockers may also make treatment of diabetes and thyroid disorders more complicated. Your physician will need to monitor such conditions closely.

• Antacids containing aluminum or calcium and aspirin, ibuprofen: These can reduce absorption and interfere with the effectiveness of metoprolol (Lopressor, Toprol-XL).

• NSAID arthritis drugs such as ibuprofen, naproxen, and high dose aspirin can reduce the effectiveness of metoprolol.

• Cimetidine (Tagamet) and ranitidine (Zantac): Ulcer drugs may increase the effects of metoprolol (Lopressor, Toprol-XL).

• Barbiturates (phenobarbital) and tuberculosis antibiotics (rifampin): These drugs may reduce the effect of beta-blockers.

There may be other drug interactions not listed here. Do not start any new medications or make changes to your treatment without first consulting your prescribing physician.


1. Lindholm, L. H., et al. “Should Beta-Blockers Remain First Choice in the Treatment of Primary Hypertension? A Meta-Analysis.” Lancet 2005; 366:1545-1553.

2. Kaplan, N.M., and Opie, L.H. “Controversies in Hypertension.” Lancet 2006; 367:168-176.

3. Beevers, D.G. “The End of Beta-Blockers for Uncomplicated Hypertension?” Lancet 2005; 366:1510-1512.

Be certain to consult a physician about your health, especially with regard to any signs or symptoms that may require diagnosis or medical attention. Information provided is not a substitute for the medical advice or care of a physician or other health care professional.

Join Over 53,000 Subscribers at The People's Pharmacy

Each week we send two free email newsletters with breaking health news, prescription drug information, home remedies and a preview of our award-winning radio show. Join our mailing list and get the information you need to make confident choices about your health.

  1. andrea

    Hi I’ve been experiencing the same thing. I recently got off metoprolol and ever since then I’ve been super anxious. It’s been about 5 days. And I can’t stand it. How long do you have the anxiousness?

  2. Genet

    I’m recently taking 150 MG Metroprolol succinate every day. It doesn’t work effectively. My heart rate is good in 60 but sometimes my BP get high with no reason. I started with 25 MG then to 50 mg then to 100 and now 150 mg. It’s early in the morning (4:30 am) I woke up with pounding heart beat my Bp is 182/105 heart rate 92. I have no side effect with this medication, and I’ve been taking it for around 2 months. I can’t wait to make appointment with my doctor this morning and change to another medication.

  3. M

    I was on 25mg of Metoprolol twice a day for about 2 months. My doctor told me to stop them cold turkey, as I wasn’t on them for very long in the first place. I decided to do a short wean process (about five days) and have been off them mostly for about two weeks now. I have been incredibly anxious since then, and have had at least two episodes of tachycardia (once at about 120 bpm, another nearing 140). I am curious how long these effects will last, and if I should just go back on the pill? I’ve been reading that getting off of these pills can be dangerous, and I don’t know if I have passed that window of danger or not.

What Do You Think?

Share your thoughts with others, but be mindful of protecting your own and others' privacy. Not all comments will be posted. Advice from web visitors is not a substitute for medical attention. Do not stop any medicine without checking with the prescriber. In posting a comment, you agree to our commenting policy and website terms and conditions.