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Label Changes for:

Lopressor (metoprolol tartrate) 50 mg / 100 mg TabletsLopressor (metoprolol tartrate) 5 mg / 5 ml injection

March 2013

Changes have been made to the WARNINGS and PRECAUTIONS sections of the safety label.

Detailed View: Safety Labeling Changes Approved By FDA Center for Drug Evaluation and Research (CDER) 



March 2013


Heart Failure
  • Beta blockers, like Lopressor, can cause depression of myocardial contractility and may precipitate heart failure and cardiogenic shock. If signs or symptoms of heart failure develop, treat the patient according to recommended guidelines. It may be necessary to lower the dose of Lopressor or to 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 betablockers.
Use During Major Surgery
  • Chronically administered beta-blocking therapy should not be routinely withdrawn prior to major surgery; however, the impaired ability of the heart to respond to reflex adrenergic stimuli may augment the risks of general anesthesia and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. Monitor heart rate and rhythm in patients receiving Lopressor. If severe bradycardia develops, reduce or stop Lopressor.
Exacerbation of Bronchospastic Diseases
  • ...Bronchodilators, including beta2 agonists, should be readily available or administered concomitantly.


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.


December 2012



  • Start at a low dose and uptitrate slowly…
Drug Interactions
  • Catecholamine-depleting drugs….
CYP2D6 Inhibitors:
  • …..Increase in  plasma concentrations of Metoprolol would decrease the cardioselectivity of Metoprolol…
  • Hydralazine: Concomitant administration of hydralazine may inhibit presystemic metabolism of metoprolol leading to increased concentrations of metoprolol.
  • Alpha-adrenergic agents: Antihypertensive effect of alpha-adrenergic blockers such as guanethidine, betanidine, reserpine, alpha-methyldopa or clonidine may be potentiated by betablockers including Lopressor…
  • Ergot alkaloid: Concomitant administration with beta-blockers may enhance the vasoconstrictive action of ergot alkaloids.
  • Dipyridamole: In general, administration of a beta-blocker should be withheld before dipyridamole testing, with careful monitoring of heart rate following the dipyridamole injection.
Carcinogenesis, Mutagenesis, Impairment of Fertility
  • Reproduction toxicity studies in mice, rats and rabbits did not indicate teratogenic potential for metoprolol tartrate…
Pregnancy Category C
  • Upon confirming the diagnosis of pregnancy, women should immediately inform the doctor…
  • The effects of Lopressor on the fertility of human have not been studied…