Norepinephrine

12.1 Mechanism of Action Norepinephrine is a peripheral vasoconstrictor (alpha-adrenergic action) and an inotropic stimulator of the heart and dilator of coronary arteries (beta-adrenergic action).

1 INDICATIONS AND USAGE Norepinephrine bitartrate injection is indicated to raise blood pressure in adult patients with severe, acute hypotension. Norepinephrine bitartrate injection is a catecholamine indicated for restoration of blood pressure in adult patients with acute hypotensive states. ( 1 )

2 DOSAGE AND ADMINISTRATION Initial dose of 0.25 mL to 0.375 mL (from 8 mcg to 12 mcg of base) per minute, adjust the rate of flow to establish and maintain a low to normal blood pressure (usually 80 mm Hg to 100 mm Hg systolic) sufficient to maintain the circulation of vital organs. ( 2.2 ) The average maintenance dose ranges from 0.0625 mL to 0.125 mL per minute (from 2 mcg to 4 mcg of base). ( 2.2 ) 2.1 Important Dosage and Administration Instructions Correct Hypovolemia Address hypovolemia before initiation of norepinephrine bitartrate injection therapy. If the patient does not respond to therapy, suspect occult hypovolemia [see Warnings and Precautions (5.1) ] . Administration Dilute norepinephrine bitartrate injection prior to use [see Dosage and Administration (2.3) ] . Infuse norepinephrine bitartrate injection into a large vein. Avoid infusions into the veins of the leg in the elderly or in patients with occlusive vascular disease of the legs [see Warnings and Precautions (5.1) ]. Avoid using a catheter-tie-in technique . Discontinuation When discontinuing the infusion, reduce the flow rate gradually. Avoid abrupt withdrawal. 2.2 Dosage After an initial dosage of 8 to 12 mcg per minute via intravenous infusion, assess patient response and adjust dosage to maintain desired hemodynamic effect. Monitor blood pressure every two minutes until the desired hemodynamic effect is achieved, and then monitor blood pressure every five minutes for the duration of the infusion. Typical maintenance intravenous dosage is 2 to 4 mcg per minute. 2.3 Preparation of Diluted Solution Visually inspect norepinephrine bitartrate injection for particulate matter and discoloration prior to administration (the solution is colorless). Do not use the solution if its color is pinkish or darker than slightly yellow or if it contains a precipitate. Add the content of one norepinephrine bitartrate injection vial (4 mg in 4 mL) to 1,000 mL of 5% Dextrose Injection, USP or Sodium Chloride Injection solutions that contain 5% dextrose to produce a 4 mcg per mL dilution. Dextrose reduces loss of potency due to oxidation. Administration in saline solution alone is not recommended. Use higher concentration solutions in patients requiring fluid restriction. Prior to use, store the diluted norepinephrine bitartrate injection solution for up to 24 hours at room temperature [20°C to 25°C (68°F to 77°F)] and protect from light. 2.4 Drug Incompatibilities Avoid contact with iron salts, alkalis, or oxidizing agents. Whole blood or plasma, if indicated to increase blood volume, should be administered separately.

6 ADVERSE REACTIONS The following adverse reactions are described in greater detail in other sections: Tissue Ischemia [see Warnings and Precautions (5.1) ] Hypotension [see Warnings and Precautions (5.2) ] Cardiac Arrhythmias [see Warnings and Precautions (5.3) ] The most common adverse reactions are hypertension and bradycardia. The following adverse reactions can occur: Nervous system disorders: Anxiety, headache Respiratory disorders: Respiratory difficulty, pulmonary edema Most common adverse reactions are ischemic injury, bradycardia, anxiety, transient headache, respiratory difficulty, and extravasation necrosis at injection site. (6) To report SUSPECTED ADVERSE REACTIONS, contact Biocon Pharma Inc., at 1-866-924-6266 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

7 DRUG INTERACTIONS Monoamine oxidase inhibitors (MAOI) or antidepressants of the triptyline or imipramine types may result in hypertension. ( 7.1 ) Cyclopropane and halothane anesthetics increase cardiac autonomic irritability. ( 7.4 ) 7.1 MAO-Inhibiting Drugs Co-administration of norepinephrine bitartrate with monoamine oxidase (MAO) inhibitors or other drugs with MAO-inhibiting properties (e.g., linezolid) can cause severe, prolonged hypertension. If administration of norepinephrine bitartrate cannot be avoided in patients who recently have received any of these drugs and in whom, after discontinuation, MAO activity has not yet sufficiently recovered, monitor for hypertension. 7.2 Tricyclic Antidepressants Co-administration of norepinephrine bitartrate with tricyclic antidepressants (including amitriptyline, nortriptyline, protriptyline, clomipramine, desipramine, imipramine) can cause severe, prolonged hypertension. If administration of norepinephrine bitartrate cannot be avoided in these patients, monitor for hypertension. 7.3 Antidiabetics Norepinephrine bitartrate can decrease insulin sensitivity and raise blood glucose. Monitor glucose and consider dosage adjustment of antidiabetic drugs. 7.4 Halogenated Anesthetics Concomitant use of norepinephrine bitartrate with halogenated anesthetics (e.g., cyclopropane, desflurane, enflurane, isoflurane, and sevoflurane) may lead to ventricular tachycardia or ventricular fibrillation. Monitor cardiac rhythm in patients receiving concomitant halogenated anesthetics.