5 WARNINGS AND PRECAUTIONS
5.1 Hypertension
Because individual response to epinephrine may vary significantly, monitor blood pressure frequently and titrate to avoid excessive increases in blood pressure.
Patients receiving monoamine oxidase inhibitors (MAOI) or antidepressants of the triptyline or imipramine types may experience severe, prolonged hypertension when given epinephrine.
5.2 Pulmonary Edema
Epinephrine increases cardiac output and causes peripheral vasoconstriction, which may result in pulmonary edema.
5.3 Cardiac Arrhythmias and Ischemia
Epinephrine may induce cardiac arrhythmias and myocardial ischemia in patients, especially patients with coronary artery disease, or cardiomyopathy [see Adverse Reactions and Drug Interactions (7.3)].
5.4 Extravasation and Tissue Necrosis with Intravenous Infusion
Avoid extravasation of epinephrine into the tissues, to prevent local necrosis. When Epinephrine Injection is administered intravenously, check the infusion site frequently for free flow. Blanching along the course of the infused vein, sometimes without obvious extravasation, may be attributed to vasa vasorum constriction with increased permeability of the vein wall, permitting some leakage. This also may progress on rare occasions to a superficial slough. Hence, if blanching occurs, consider changing the infusion site at intervals to allow the effects of local vasoconstriction to subside.
There is potential for gangrene in a lower extremity when infusions of catecholamine are given in an ankle vein.
Antidote for Extravasation Ischemia: To prevent sloughing and necrosis in areas in which extravasation has taken place, infiltrate the area with 10 mL to 15 mL of saline solution containing from 5 mg to 10 mg of phentolamine, an adrenergic blocking agent. Use a syringe with a fine hypodermic needle, with the solution being infiltrated liberally throughout the area, which is easily identified by its cold, hard, and pallid appearance. Sympathetic blockade with phentolamine causes immediate and conspicuous local hyperemic changes if the area is infiltrated within 12 hours.
5.5 Renal Impairment
Epinephrine constricts renal blood vessels, which may result in oliguria or renal impairment.
5.6 Allergic Reactions associated with Sulfite
Epinephrine Injection contains sodium metabisulfite which may cause mild to severe allergic reactions including anaphylaxis or asthmatic episodes, particularly in patients with a history of allergies. The presence of sodium metabisulfite in this product should not preclude its use for the treatment of hypotension associated with septic shock even if the patient is sulfite-sensitive, as the alternatives to using epinephrine in a life-threatening situation may not be satisfactory. In susceptible patients, consider using a formulation of epinephrine or another vasoconstrictor that does not contain sodium metabisulfite.