Overview
11 DESCRIPTION Metoprolol Tartrate Injection, USP is a selective beta 1 -adrenoreceptor blocking agent, available in 5 mL vials for intravenous administration. Each vial contains a sterile solution of Metoprolol Tartrate USP, 5 mg, and Sodium Chloride, USP, 45 mg, and Water for Injection, USP.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Metoprolol is a beta 1 -selective (cardioselective) adrenergic receptor blocking agent. This preferential effect is not absolute, however, and at higher plasma concentrations, metoprolol also inhibits beta 2 -adrenoreceptors, chiefly located in the bronchial and vascular musculature. Metoprolol has no intrinsic sympathomimetic activity, and membrane-stabilizing activity is detectable only at plasma concentrations much greater than required for beta-blockade. Animal and human experiments indicate that metoprolol slows the sinus rate and decreases AV nodal conduction.
Indications
- 1 INDICATIONS AND USAGE Metoprolol Tartrate Injection, USP is indicated in the treatment of definite or suspected acute myocardial infarction in hemodynamically stable patients to reduce cardiovascular mortality when used in conjunction with oral metoprolol maintenance therapy. Metoprolol Tartrate Injection is a beta-adrenergic receptor inhibitor indicated for the treatment of definite or suspected acute myocardial infarction in hemodynamically stable patients to reduce cardiovascular mortality when used in conjunction with oral metoprolol maintenance therapy. ( 1 )
Common Doses
- 5 mg
Dosage
2 DOSAGE AND ADMINISTRATION Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Initiate treatment in a coronary care or similar unit immediately after the patient’s hemodynamic condition has stabilized. Begin treatment in this early phase with the intravenous administration of three bolus injections of 5 mg of Metoprolol Tartrate Injection each; give the injections at approximately 2-minute intervals.
Contraindications
- 4 CONTRAINDICATIONS Hypersensitivity to Metoprolol Tartrate Injection and related derivatives, or to any of the excipients; hypersensitivity to other beta blockers (cross sensitivity between beta blockers can occur). Metoprolol Tartrate Injection is contraindicated in patients with a heart rate
Side Effects
- 6 ADVERSE REACTIONS The following adverse reactions are described elsewhere in labeling: Worsening angina or myocardial infarction [see Warnings and Precautions (5) ] Worsening heart failure [see Warnings and Precautions (5) ] Worsening AV block [see Contraindications (4) ] • Most common adverse reactions: tiredness, dizziness, shortness of breath, bradycardia, hypotension, pruritus. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Hikma Pharmaceuticals USA Inc. at 1-877-845-0689 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.
Interactions
- 7 DRUG INTERACTIONS Catecholamine-depleting drugs may have an additive effect when given with beta-blocking agents. ( 7.1) Patients may be unresponsive to the usual doses of epinephrine used to treat allergic reaction. (7.2 ) CYP2D6 Inhibitors are likely to increase metoprolol concentration. ( 7.3 ) Concomitant use of glycosides, clonidine, and diltiazem and verapamil with beta-blockers can increase the risk of bradycardia. ( 7.4 ) Beta-blockers including metoprolol, may exacerbate the rebound hypertension that can follow the withdrawal of clonidine. ( 7.4 ) 7.