Norepinephrine Bitartrate

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.

4 CONTRAINDICATIONS None. None. ( 4 )

5 WARNINGS AND PRECAUTIONS Tissue Ischemia : Avoid extravasation of norepinephrine bitartrate into the tissues, as local necrosis might ensue due to the vasoconstrictive action of the drug. Infuse norepinephrine bitartrate into a large vein. To prevent sloughing and necrosis in areas in which extravasation has taken place, the area should be infiltrated as soon as possible with 10 mL to 15 mL of saline solution containing from 5 mg to 10 mg of an adrenergic blocking agent. ( 5.1 ) Hypotension After Abrupt Discontinuation : Sudden cessation of the infusion rate may result in marked hypotension. Reduce the norepinephrine bitartrate infusion rate gradually. ( 5.2 ) Cardiac Arrhythmias : Norepinephrine Bitartrate may cause arrhythmias. Monitor cardiac function in patients with underlying heart disease. ( 5.3 ) Allergic Reactions with Sulfite : Norepinephrine Bitartrate contains sodium metabisulfite. Sulfite may cause allergic-type-reactions. ( 5.4 ) 5.1 Tissue Ischemia Administration of norepinephrine bitartrate to patients who are hypotensive from hypovolemia can result in severe peripheral and visceral vasoconstriction, decreased renal perfusion and reduced urine output, tissue hypoxia, lactic acidosis, and reduced systemic blood flow despite “normal” blood pressure. Address hypovolemia prior to initiating norepinephrine bitartrate [see Dosage and Administration ( 2.1 )]. Avoid norepinephrine bitartrate in patients with mesenteric or peripheral vascular thrombosis, as this may increase ischemia and extend the area of infarction. Gangrene of the extremities has occurred in patients with occlusive or thrombotic vascular disease or who received prolonged or high dose infusions. Monitor for changes to the skin of the extremities in susceptible patients. Extravasation of norepinephrine bitartrate may cause necrosis and sloughing of surrounding tissue. To reduce the risk of extravasation, infuse into a large vein, check the infusion site frequently for free flow, and monitor for signs of extravasation [see Dosage and Administration ( 2.1 )]. Emergency Treatment of Extravasation To prevent sloughing and necrosis in areas in which extravasation has occurred, infiltrate the ischemic area as soon as possible, using a syringe with a fine hypodermic needle with 5 to 10 mg of phentolamine mesylate in 10 to 15 mL of 0.9% Sodium Chloride Injection in adults. Sympathetic blockade with phentolamine causes immediate and conspicuous local hyperemic changes if the area is infiltrated within 12 hours. 5.2 Hypotension after Abrupt Discontinuation Sudden cessation of the infusion rate may result in marked hypotension. When discontinuing the infusion, gradually reduce the norepinephrine bitartrate infusion rate while expanding blood volume with intravenous fluids. 5.3 Cardiac Arrhythmias Norepinephrine Bitartrate elevates intracellular calcium concentrations and may cause arrhythmias, particularly in the setting of hypoxia or hypercarbia. Perform continuous cardiac monitoring of patients with arrhythmias. 5.4 Allergic Reactions Associated with Sulfite Norepinephrine Bitartrate Injection contains sodium metabisulfite, a sulfite that may cause allergic-type reactions including anaphylactic symptoms and life-threatening or less severe asthmatic episodes in certain susceptible people. The overall prevalence of sulfite sensitivity in the general population is unknown. Sulfite sensitivity is seen more frequently in asthmatic than in non-asthmatic people.

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.

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 Sagent Pharmaceuticals at 1-866-625-1618 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

8.1 Pregnancy Risk Summary Limited published data consisting of a small number of case reports and multiple small trials involving the use of norepinephrine in pregnant women at the time of delivery have not identified an increased risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. There are risks to the mother and fetus from hypotension associated with septic shock, myocardial infarction and stroke which are medical emergencies in pregnancy and can be fatal if left untreated. (see Clinical Considerations) . In animal reproduction studies, using high doses of intravenous norepinephrine resulted in lowered maternal placental blood flow. Clinical relevance to changes in the human fetus is unknown since the average maintenance dose is ten times lower (see Data). Increased fetal reabsorptions were observed in pregnant hamsters after receiving daily injections at approximately 2 times the maximum recommended dose on a mg/m 3 basis for four days during organogenesis (see Data). The estimated background risk for major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in the clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Clinical Considerations Disease-associated maternal and/or embryo/fetal risk Hypotension associated with septic shock, myocardial infarction, and stroke are medical emergencies in pregnancy which can be fatal if left untreated. Delaying treatment in pregnant women with hypotension associated with septic shock, myocardial infarction and stroke may increase the risk of maternal and fetal morbidity and mortality. Life-sustaining therapy for the pregnant woman should not be withheld due to potential concerns regarding the effects of norepinephrine on the fetus. Data Animal Data A study in pregnant sheep receiving high doses of intravenous norepinephrine (40 mcg/min, at approximately 10 times the average maintenance dose of 2 to 4 mcg/min in human, on a mg/kg basis) exhibited a significant decrease in maternal placental blood flow. Decreases in fetal oxygenation, urine and lung liquid flow were also observed. Norepinephrine administration to pregnant rats on Gestation Day 16 or 17 resulted in cataract production in rat fetuses. In hamsters, an increased number of resorptions (29.1% in study group vs. 3.4% in control group), fetal microscopic liver abnormalities and delayed skeletal ossification were observed at approximately 2 times the maximum recommended intramuscular or subcutaneous dose (on a mg/m 2 basis at a maternal subcutaneous dose of 0.5 mg/kg/day from Gestation Day 7 to 10).