Lopressor® (metoprolol tartrate) Tablets should be taken by mouth, with or right after a meal, as directed by your doctor, usually 1-3 times daily. The specific dosage of Lopressor that your doctor directs you to take will be based on your medical condition and your response to treatment.

Use this medicine regularly to get the most benefit from it. To help you remember, take it at the same time(s) each day. Do not take this medicine in larger or smaller amounts, unless directed by your doctor.

Do not suddenly stop taking this medicine without consulting your doctor because your condition may become worse if you suddenly stop taking Lopressor without consulting your doctor. Some people who have suddenly stopped similar drugs have had chest pain, heart attack and irregular heartbeat. If your doctor decides you should no longer use this drug, he or she may direct you to gradually decrease your dose over a 1 to 2 week period.

For the treatment of high blood pressure, it may take several weeks before your body receives the full benefit of Lopressor. It is important to continue using this drug even if you feel good, as most people with high blood pressure do not feel sick.

Tell your doctor if your condition does not improve or worsens.


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

  • A serious heart problem such as heart block, sick sinus syndrome, or slow heart rate;
  • Severe circulation problems;
  • Severe heart failure (that required hospitalization); or
  • History of slow heart beats that caused you to faint.

Lopressor may contain inactive ingredients (including cellulose compounds, colloidal silicon dioxide, D&C Red No. 3 aluminum lake, FD&C Blue No. 2 aluminum lake, lactose, magnesium stearate, PEG, propylene glycol, povidone, sodium starch glycolate, talc and titanium dioxide) which can cause allergic reactions or other problems.

You should tell your doctor if you have any of the following conditions:

  • Asthma, chronic obstructive pulmonary disease (COPD), sleep apnea, or other breathing disorders;
  • Diabetes (taking Lopressor may make it harder for you to tell when you have low blood sugar);
  • Liver disease;
  • Congestive heart failure;
  • Circulation problems (such as Raynaud’s syndrome);
  • A thyroid disorder; or
  • Depression.

Considerations if you have diabetes:

If you have diabetes, Lopressor may prevent the fast/pounding heartbeat you would usually feel when your blood sugar falls too low (hypoglycemia). Other symptoms of low blood sugar levels, such as dizziness and sweating, are unaffected by Lopressor. Lopressor may also make it harder to control your blood sugar levels. You should have your blood sugar checked regularly, as directed by your doctor. Tell your doctor immediately if you have symptoms of high blood sugar such as increased thirst and urination. Your doctor may need to adjust your diabetes medication, exercise program or diet.

If you are having surgery, make sure your surgeon knows that you are taking Lopressor.

Before having surgery, tell your doctor or dentist about all the products you use, including prescription drugs, nonprescription drugs, and herbal products.

Effects of Lopressor:

Lopressor may make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are confident that you can perform these activities safely while taking Lopressor. Limit alcoholic beverages while on this medication.

Tell your doctor if you are pregnant, intend to become pregnant, or intend to breastfeed.

During pregnancy, Lopressor should only be used when clearly needed. Talk to your doctor as the medicine can cause harm to your unborn child. In addition, this drug passes into breast milk so you should discuss the risks and benefits of using this drug while breast feeding with your doctor.


Tell your doctor if you are taking any other medicines, including any that you buy without a prescription from a pharmacy, supermarket or healthfood shop.

Some medicines and Lopressor may interfere with each other. These include:

  • Bupropion;
  • Prazosin;
  • Terbinafine;
  • Certain antidepressants including bupropion, clomipramine, desipramine, duloxetine, fluoxetine, fluvoxamine, paroxetine, and sertraline;
  • Ergot medicines such as dihydroergotamine, ergonovine, ergotamine, and methylergonovine;
  • Heart or blood pressure medicines such as amlodipine, clonidine, digoxin, diltiazem, dipyridamole, hydralazine, methyldopa, nifedinpine, quinidine, reserpine, verapamil, and others;
  • MAO inhibitors such as isocarboxyzid, linezolid, phenelzine, rasagiline, selegiline, and tranylcypromine; or
  • Medicine to treat mental illness such as chlorpromazine, fluphenazine, haloperidol, and thioridazine.

This is not a complete list. Other drugs may interact with Lopressor, including prescription and over-the-counter medicines and herbal supplements. Always provide your doctor with a list of all medicines you are taking.

You may need to take different amounts of medicine or to take different medicine while you are taking Lopressor. Your doctor and pharmacist have more information.

Make sure you tell your doctor about any of these medicines or over-the-counter drugs before you start taking Lopressor.


Download Full Prescribing Information

Lopressor® (metoprolol tartrate) 50mg and 100mg Tablets


Lopressor® (metoprolol tartrate) Tablets are contraindicated in patients with hypertension and angina, particularly in sinus bradycardia, certain types of heart blockages (greater than first degree), cardiogenic shock, and obvious cardiac failure. Hypersensitivity to Lopressor and related derivatives, or to any of the excipients, or to other beta-blockers can occur.

Sick sinus syndrome, which may result in irregular heartbeat, can occur, as can severe peripheral arterial circulatory disorders.

Myocardial Infarction

Lopressor is contraindicated in patients having a heart rate <45 beats per minute; second-and third-degree heart block; significant first-degree heart block (P-R interval >0.24 sec), systolic blood pressure <100mmHg, or moderate-to-severe heart failure.


Heart Failure

Beta-blocker(s), like Lopressor, may precipitate heart failure and cardiogenic shock. If this occurs, it may be necessary to lower the dose of Lopressor or discontinue it.

Ischemic Heart Disease

Do not abruptly discontinue Lopressor therapy in patients with coronary artery disease. Severe exacerbation of angina, myocardial infarction and ventricular arrhythmias have been reported in patients with coronary artery disease following the abrupt discontinuation of therapy with beta-blockers. When discontinuing chronically administered Lopressor, particularly in patients with coronary artery disease, the dosage should be gradually reduced over a period of 1-2 weeks and the patient should be carefully monitored. If angina markedly worsens or acute coronary insufficiency develops, Lopressor administration should be reinstated promptly, at least temporarily, and other measures appropriate for the management of unstable angina should be taken. Patients should be warned against interruption or discontinuation of therapy without the physician’s advice. Because coronary artery disease is common and may be unrecognized, it may be prudent not to discontinue Lopressor therapy abruptly even in patients treated only for hypertension.

Use During Major Surgery

Chronically administered beta-blocking therapy should not be withdrawn prior to major surgery; however, the impaired ability of the heart to respond to reflex adrenergic stimuli may increase the risks of general anesthesia and surgical procedures.


Bradycardia, including sinus pause, heart block, and cardiac arrest have occurred with the use of Lopressor. Patients with first-degree atrioventricular block, sinus node dysfunction, or conduction disorders may be at increased risk.

Exacerbation of Bronchospastic Disease

Patients with bronchospastic disease should not generally receive beta blockers. However, because of its relative beta1 selectivity, Lopressor may be used in patients with bronchospastic disease who do not respond to, or who cannot tolerate, other antihypertensive treatment.

Diabetes and Hypoglycemia

Beta-blockers may mask tachycardia occurring with hypoglycemia, but other manifestations such as dizziness and sweating may not be significantly affected.


If Lopressor is used in the setting of pheochromocytoma, it should be given in combination with an alpha blocker, and only after the alpha blocker has been initiated.


Lopressor may mask certain clinical signs (e.g., tachycardia) of hyperthyroidism. Avoid abrupt withdrawal of beta-blockade, which might precipitate a thyroid storm.

Risk of Anaphylactic Reactions

While taking beta-blockers, patients with a history of severe anaphylactic reaction to a variety of allergens may be more reactive to repeated challenge, either accidental, diagnostic, or therapeutic. Such patients may be unresponsive to the usual doses of epinephrine used to treat allergic reaction.

Drug Interactions

Catecholamine-depleting drugs (e.g., reserpine) may have an additive effect when given with beta-blocking agents or monoamine oxidase (MAO) inhibitors. Both digitalis glycosides and beta-blockers slow atrioventricular conduction and decrease heart rate. Concomitant use can increase the risk of bradycardia. Concomitant administration of a beta-adrenergic antagonist with a calcium channel blocker may produce an additive reaction in myocardial contractility because of negative chronotropic and inotropic effects. Potent inhibitors of the CYP2D6 enzyme may increase plasma concentration of Lopressor. Concomitant administration of hydralazine may inhibit presystemic metabolism of metoprolol leading to increased concentrations of metoprolol. Lopressor may increase the hypertensive effects of alpha-adrenergic blockers. Concomitant administration with beta-blockers may enhance the vasoconstrictive action of ergot alkaloids. In general, administration of beta-blockers should be withheld before dipyridamole testing, with careful monitoring of heart rate following the dipyridamole injection.

Pregnancy Category C

Upon confirming the diagnosis of pregnancy, women should immediately inform their doctor. The amount of data on the use of Lopressor in pregnant women is limited. Lopressor is excreted in breast milk in very small quantities.

Pediatric and Geriatric use of Lopressor has not been studied.

Adverse Reactions

Hypertension and Angina: Most adverse effects have been mild and transient.

Central Nervous System: Tiredness and dizziness have occurred in about 10% of patients.

Cardiovascular: Shortness of breath and bradycardia has occurred in about 3% of patients.

Respiratory: Wheezing and dyspnea have been reported in about 1% of patients.

Gastrointestinal: Diarrhea has occurred in about 5% of patients.

Hypersensitive Reactions: Pruritis or rash has occurred in about 5% of patients.


Acute Toxicity: Several cases of overdosage have been reported, some leading to death.

Signs and Symptoms: Potential signs and symptoms associated with Lopressor overdose are bradycardia, hypotension, bronchospasm, myocardial infarction, cardiac failure, and death. There is no specific antidote.

To report SUSPECTED ADVERSE REACTIONS, contact Validus Pharmaceuticals, LLC at — VALIDUS (1-866-982-5438) or FDA at 1-800-FDA-1088 or