ADVERSE REACTIONS SECTION.

6 ADVERSE REACTIONS The following serious adverse reactions are described in greater detail in other sections:oTissue Ischemia [see Warnings and Precautions (5.1)]oHypotension [see Warnings and Precautions (5.2)]oCardiac 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, headacheRespiratory disorders: Respiratory difficulty, pulmonary edemaGeneral disorders and administration site conditions: Extravasation, injection site necrosis [see Warnings and Precautions (5.1)].. oTissue Ischemia [see Warnings and Precautions (5.1)]. oHypotension [see Warnings and Precautions (5.2)]. oCardiac Arrhythmias [see Warnings and Precautions (5.3)]. Serious adverse reactions are described in greater detail in other sections [see Warnings and Precautions (5.1, 5.2, 5.3)].Most common adverse reactions are hypertension, bradycardia, ischemic injury, anxiety, headache, respiratory difficulty, pulmonary edema, and extravasation necrosis at injection site. (6)To report SUSPECTED ADVERSE REACTIONS, contact Baxter Healthcare at 1-866-888-2472 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

CLINICAL PHARMACOLOGY SECTION.

12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Norepinephrine is peripheral vasoconstrictor (alpha-adrenergic action) and an inotropic stimulator of the heart and dilator of coronary arteries (beta-adrenergic action).. 12.2 Pharmacodynamics The primary pharmacodynamic effects of norepinephrine are cardiac stimulation and vasoconstriction. Cardiac output is generally unaffected, although it can be decreased, and total peripheral resistance is also elevated. The elevation in resistance and pressure result in reflex vagal activity, which slows the heart rate and increases stroke volume. The elevation in vascular tone or resistance reduces blood flow to the major abdominal organs as well as to skeletal muscle. Coronary blood flow is substantially increased secondary to the indirect effects of alpha stimulation. After intravenous administration, pressor response occurs rapidly and reaches steady state within minutes. The pharmacologic actions of norepinephrine are terminated primarily by uptake and metabolism in sympathetic nerve endings. The pressor action stops within 1-2 minutes after the infusion is discontinued. 12.3 Pharmacokinetics AbsorptionFollowing initiation of intravenous infusion, the steady state plasma concentration is achieved in min. DistributionPlasma protein binding of norepinephrine is approximately 25%. It is mainly bound to plasma albumin and to smaller extent to prealbumin and alpha 1-acid glycoprotein. The volume of distribution is 8.8 L. Norepinephrine localizes mainly in sympathetic nervous tissue. It crosses the placenta but not the blood-brain barrier.EliminationThe mean half-life of norepinephrine is approximately 2.4 min. The average metabolic clearance is 3.1 L/min.MetabolismNorepinephrine is metabolized in the liver and other tissues by combination of reactions involving the enzymes catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO). The major metabolites are normetanephrine and 3-methoxy-4-hydroxy mandelic acid (vanillylmandelic acid, VMA), both of which are inactive. Other inactive metabolites include 3-methoxy-4-hydroxyphenylglycol, 3,4-dihydroxymandelic acid, and 3,4-dihydroxyphenylglycol.ExcretionNorepinephrine metabolites are excreted in urine primarily as the sulfate conjugates and, to lesser extent, as the glucuronide conjugates. Only small quantities of norepinephrine are excreted unchanged.

DESCRIPTION SECTION.

11 DESCRIPTION Norepinephrine Bitartrate in Dextrose Injection contains norepinephrine, sympathomimetic amine. Norepinephrine is sometimes referred to as l-arterenol/Levarterenol or l-norepinephrine which differs from epinephrine by the absence of methyl group on the nitrogen atom.Chemically, norepinephrine bitartrate monohydrate is (-)--(aminomethyl)-3,4-dihydroxybenzyl alcohol tartrate (1:1) (salt) monohydrate and has the following structural formula:Norepinephrine is sparingly soluble in water, very slightly soluble in alcohol and ether, and readily soluble in acids.Norepinephrine Bitartrate in Dextrose Injection is supplied as sterile aqueous solution administered by intravenous infusion. Each mL contains the equivalent of 16 or 32 micrograms of norepinephrine base supplied as 31.90 and 63.80 micrograms per mL of norepinephrine bitartrate monohydrate. It contains dextrose monohydrate (50 mg/mL) and may contain hydrochloric acid and/or sodium hydroxide for pH adjustment. It has pH of 3.5 3.9. The air in the containers has been displaced by nitrogen gas.. Structural Formula.

DOSAGE & ADMINISTRATION SECTION.

2 DOSAGE AND ADMINISTRATION oNo further dilution prior to infusion is required. (2.1)oInitiate at to 12 mcg/min, and adjust the rate to maintain blood pressure sufficient to maintain the circulation of vital organs. (2.2)oThe average maintenance dose ranges from to mcg/min. (2.2). oNo further dilution prior to infusion is required. (2.1). oInitiate at to 12 mcg/min, and adjust the rate to maintain blood pressure sufficient to maintain the circulation of vital organs. (2.2). oThe average maintenance dose ranges from to mcg/min. (2.2). 2.1 Important Dosage and Administration Instructions Correct HypovolemiaAddress hypovolemia before initiation of Norepinephrine Bitartrate in Dextrose Injection therapy. If the patient does not respond to therapy, suspect occult hypovolemia [see Warnings and Precautions (5.1)].AdministrationNorepinephrine Bitartrate in Dextrose Injection is ready to administer product that requires no further dilution prior to infusion. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Do not use the solution if its color is pinkish or darker than slightly yellow or if it contains precipitate.Infuse Norepinephrine Bitartrate in Dextrose Injection into 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 catheter-tie-in technique.The choice of appropriate concentration of Norepinephrine Bitartrate in Dextrose Injection depends on clinical fluid volume requirements. Use higher concentration solutions in patients requiring fluid restriction.DiscontinuationWhen discontinuing the infusion, reduce the flow rate gradually. Avoid abrupt withdrawal.. 2.2 Dosage After an initial dosage of 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 to mcg per minute.. 2.3 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.

DOSAGE FORMS & STRENGTHS SECTION.

3 DOSAGE FORMS AND STRENGTHS Injection: Norepinephrine bitartrate in 5% dextrose is colorless to slightly yellow solution for intravenous infusion, supplied in 250-mL single dose containers as:o4 mg equivalent of norepinephrine (16 mcg/mL).o8 mg equivalent of norepinephrine (32 mcg/mL).. o4 mg equivalent of norepinephrine (16 mcg/mL).. o8 mg equivalent of norepinephrine (32 mcg/mL).. Injection: 250-mL single dose-containers with o4 mg equivalent of norepinephrine (16 mcg/mL) in 5% dextrose.o8 mg equivalent of norepinephrine (32 mcg/mL) in 5% dextrose.. o4 mg equivalent of norepinephrine (16 mcg/mL) in 5% dextrose.o8 mg equivalent of norepinephrine (32 mcg/mL) in 5% dextrose.. o4 mg equivalent of norepinephrine (16 mcg/mL) in 5% dextrose.. o8 mg equivalent of norepinephrine (32 mcg/mL) in 5% dextrose.

DRUG INTERACTIONS SECTION.

7 DRUG INTERACTIONS oMonoamine oxidase inhibitors (MAOI) or tricyclic antidepressants of the triptyline or imipramine types may result in hypertension. (7.1, 7.2)oAntidiabetics: Norepinephrine can decrease insulin sensitivity and raise blood glucose (7.3)oCyclopropane and halothane anesthetics increase cardiac autonomic irritability. (7.4). oMonoamine oxidase inhibitors (MAOI) or tricyclic antidepressants of the triptyline or imipramine types may result in hypertension. (7.1, 7.2). oAntidiabetics: Norepinephrine can decrease insulin sensitivity and raise blood glucose (7.3). oCyclopropane and halothane anesthetics increase cardiac autonomic irritability. (7.4). 7.1 MAO-Inhibiting Drugs Co-administration of Norepinephrine Bitartrate in Dextrose Injection 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 in Dextrose Injection 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 in Dextrose Injection with tricyclic antidepressants (including amitriptyline, nortriptyline, protriptyline, clomipramine, desipramine, imipramine) can cause severe, prolonged hypertension. If administration of Norepinephrine Bitartrate in Dextrose Injection cannot be avoided in these patients, monitor for hypertension.. 7.3 Antidiabetics Norepinephrine Bitartrate in Dextrose Injection 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 in Dextrose Injection 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.

GERIATRIC USE SECTION.

8.5 Geriatric Use Clinical studies of norepinephrine did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.Avoid administration of Norepinephrine Bitartrate in Dextrose Injection into the veins in the leg in elderly patients [see Warnings and Precautions (5.1)].

HOW SUPPLIED SECTION.

16 HOW SUPPLIED/STORAGE AND HANDLING Norepinephrine Bitartrate in Dextrose Injection intravenous infusion is available in single-dose, ready-to-use containers in an amber/foil overwrap. Each 250 mL of Norepinephrine Bitartrate in Dextrose Injection 4 mg/250 mL and mg/250 mL contains the equivalent of mg and mg of norepinephrine, respectively (provided as norepinephrine bitartrate monohydrate). Norepinephrine Bitartrate in Dextrose Injection is available in the following:Product DescriptionNDC NumberTwenty (20) mg/250 mL containersNDC 0338-0112-20Twenty (20) mg/250 mL containersNDC 0338-0108-20Store between 2C to 8C (36F to 46F) in overwrap to protect from light.Norepinephrine Bitartrate in Dextrose Injection may be stored at room temperature up to 25C (77F) for up to 90 days upon removal from refrigeration. Once removed from refrigeration, the overwrap should be marked to indicate the revised 90 day expiration date and the product should not be returned to the refrigerator after it has been stored at room temperature. Once the overwrap is removed, the bag can be stored at room temperature for up to 30 days. Discard Norepinephrine Bitartrate in Dextrose Injection after 90 days if stored at room temperature or 30 days from overwrap removal.The storage conditions and expiration periods are summarized in the following table.In OverwrapRefrigerated2C to 8C (36F to 46F)In OverwrapRoom TemperatureFollowing removal from refrigeration 20C to 25C (68F to 77F)Out of OverwrapRoom Temperature 20C to 25C (68F to 77F)Until manufacturer expiration date90 days or until manufacturer expiration date, whichever is earlier30 days or until manufacturer expiration date, whichever is earlier.

PACKAGE LABEL.PRINCIPAL DISPLAY PANEL.

PACKAGE/LABEL PRINCIPAL DISPLAY PANEL Container LabelEZPE7748NDC 0338-0112-20Baxter Logo250 mLNORepinephrine Bitartratein 5% Dextrose Injection4 mg 250 mL (16 mg mL) For Intravenous Infusion OnlyEach 100mL of sterile, nonpyrogenic solution contains: Norepinephrine Bitartrate Monohydrate USP equivalent to 1.6 mg norepinephrine and g Dextrose Monohydrate in Water for Injection, USP. May contain hydrochloric acid and/or sodium hydroxide for pH adjustment.Single Dose Only Discard unused portion. For Intravenous Use.Recommended dosage: See prescribing information.Store at 20C to 25C (68F to 77F), excursions permitted to 15 to 30C (59F to 86 F) [see USP Controlled Room Temperature.] Protect from light. Keep in overwrap until ready to use. The bag should be used within 30 days of removal from overwrap.VIAFLO container is not made with natural rubber latex, DEHP, or PVC.Rx OnlyBaxter Healthcare CorporationDeerfield, IL 60015 USAMade in Ireland1CB-35-04-787VIAFLO containerSymbol07 0Do not usethis port SymbolBarcode(01)00303380112203LOTEXPContainer LabelEZPE7788Baxter LogoNDC 0338-0108-20250 mLNORepinephrine Bitartratein 5% Dextrose Injection8 mg 250 mL (32 mcg mL) For Intravenous Infusion OnlyEach 100mL of sterile, nonpyrogenic solution contains: Norepinephrine Bitartrate Monohydrate USP equivalent to3.2 mg norepinephrine and g Dextrose Monohydrate in Water for Injection, USP. May contain hydrochloric acid and/or sodium hydroxide for pH adjustment.Single Dose Only Discard unused portion. For Intravenous Use.Recommended dosage: See prescribing information.Store at 20C to 25C (68F to 77F), excursions permitted to 15C to 30C (59F to 86F). [See USP Controlled Room Temperature.] Protect from light. Keep in overwrap until ready to use. The bag should be usedwithin 30 days of removal from overwrap.VIAFLO container is not made with natural rubber latex, DEHP, or PVC.Rx OnlyBaxter Healthcare CorporationDeerfield, IL 60015 USAMade in Ireland1CB-35-04-788VIAFLO containerDo not usethis portSymbolSymbol07 0Barcode(01)00303380108206LOTEXP. Representative Norepinephrene Container Label 0338-0112-20 DRAFT. Representative Norepinephrene Container Label 0338-0108-20 DRAFT.

PHARMACODYNAMICS SECTION.

12.2 Pharmacodynamics The primary pharmacodynamic effects of norepinephrine are cardiac stimulation and vasoconstriction. Cardiac output is generally unaffected, although it can be decreased, and total peripheral resistance is also elevated. The elevation in resistance and pressure result in reflex vagal activity, which slows the heart rate and increases stroke volume. The elevation in vascular tone or resistance reduces blood flow to the major abdominal organs as well as to skeletal muscle. Coronary blood flow is substantially increased secondary to the indirect effects of alpha stimulation. After intravenous administration, pressor response occurs rapidly and reaches steady state within minutes. The pharmacologic actions of norepinephrine are terminated primarily by uptake and metabolism in sympathetic nerve endings. The pressor action stops within 1-2 minutes after the infusion is discontinued.

PHARMACOKINETICS SECTION.

12.3 Pharmacokinetics AbsorptionFollowing initiation of intravenous infusion, the steady state plasma concentration is achieved in min. DistributionPlasma protein binding of norepinephrine is approximately 25%. It is mainly bound to plasma albumin and to smaller extent to prealbumin and alpha 1-acid glycoprotein. The volume of distribution is 8.8 L. Norepinephrine localizes mainly in sympathetic nervous tissue. It crosses the placenta but not the blood-brain barrier.EliminationThe mean half-life of norepinephrine is approximately 2.4 min. The average metabolic clearance is 3.1 L/min.MetabolismNorepinephrine is metabolized in the liver and other tissues by combination of reactions involving the enzymes catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO). The major metabolites are normetanephrine and 3-methoxy-4-hydroxy mandelic acid (vanillylmandelic acid, VMA), both of which are inactive. Other inactive metabolites include 3-methoxy-4-hydroxyphenylglycol, 3,4-dihydroxymandelic acid, and 3,4-dihydroxyphenylglycol.ExcretionNorepinephrine metabolites are excreted in urine primarily as the sulfate conjugates and, to lesser extent, as the glucuronide conjugates. Only small quantities of norepinephrine are excreted unchanged.

PREGNANCY SECTION.

8.1 Pregnancy Risk SummaryLimited published data consisting of 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 times the maximum recommended dose on mg/m3 basis for four days during organogenesis (see Data).The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have 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 clinically recognized pregnancies is 2-4% and 15-20%, respectively.Clinical ConsiderationsDisease-associated maternal and/or embryo/fetal riskHypotension 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.DataAnimal DataA study in pregnant sheep receiving high doses of intravenous norepinephrine (40 mcg/min, at approximately 10 times the average maintenance dose of 2-4 mcg/min in human, on mg/kg basis) exhibited 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 times the maximum recommended intramuscular or subcutaneous dose (on mg/m2 basis at maternal subcutaneous dose of 0.5 mg/kg/day from Gestation Day 7-10).

SPL UNCLASSIFIED SECTION.

2.1 Important Dosage and Administration Instructions Correct HypovolemiaAddress hypovolemia before initiation of Norepinephrine Bitartrate in Dextrose Injection therapy. If the patient does not respond to therapy, suspect occult hypovolemia [see Warnings and Precautions (5.1)].AdministrationNorepinephrine Bitartrate in Dextrose Injection is ready to administer product that requires no further dilution prior to infusion. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Do not use the solution if its color is pinkish or darker than slightly yellow or if it contains precipitate.Infuse Norepinephrine Bitartrate in Dextrose Injection into 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 catheter-tie-in technique.The choice of appropriate concentration of Norepinephrine Bitartrate in Dextrose Injection depends on clinical fluid volume requirements. Use higher concentration solutions in patients requiring fluid restriction.DiscontinuationWhen discontinuing the infusion, reduce the flow rate gradually. Avoid abrupt withdrawal.

USE IN SPECIFIC POPULATIONS SECTION.

8 USE IN SPECIFIC POPULATIONS oElderly patients may be at greater risk of developing adverse reactions (8.5). oElderly patients may be at greater risk of developing adverse reactions (8.5). 8.1 Pregnancy Risk SummaryLimited published data consisting of 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 times the maximum recommended dose on mg/m3 basis for four days during organogenesis (see Data).The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have 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 clinically recognized pregnancies is 2-4% and 15-20%, respectively.Clinical ConsiderationsDisease-associated maternal and/or embryo/fetal riskHypotension 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.DataAnimal DataA study in pregnant sheep receiving high doses of intravenous norepinephrine (40 mcg/min, at approximately 10 times the average maintenance dose of 2-4 mcg/min in human, on mg/kg basis) exhibited 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 times the maximum recommended intramuscular or subcutaneous dose (on mg/m2 basis at maternal subcutaneous dose of 0.5 mg/kg/day from Gestation Day 7-10).. 8.2 Lactation Risk SummaryThere are no data on the presence of norepinephrine in either human or animal milk, the effects on the breastfed infant, or the effects on milk production. Clinically relevant exposure to the infant is not expected based on the short half-life and poor oral bioavailability of norepinephrine.. 8.4 Pediatric Use Safety and effectiveness in pediatric patients have not been established.. 8.5 Geriatric Use Clinical studies of norepinephrine did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.Avoid administration of Norepinephrine Bitartrate in Dextrose Injection into the veins in the leg in elderly patients [see Warnings and Precautions (5.1)].

WARNINGS AND PRECAUTIONS SECTION.

5 WARNINGS AND PRECAUTIONS oTissue Ischemia: Infuse Norepinephrine Bitartrate in Dextrose Injection into large vein. To prevent sloughing and necrosis in areas in with extravasation, infiltrate the area with an adrenergic blocking agent in saline. (5.1)oHypotension After Abrupt Discontinuation: Gradually taper norepinephrine infusion to prevent hypotension. (5.2)oCardiac Arrhythmias: Norepinephrine Bitartrate in Dextrose Injection may cause arrhythmias. Monitor cardiac function in patients with underlying heart disease. (5.3). oTissue Ischemia: Infuse Norepinephrine Bitartrate in Dextrose Injection into large vein. To prevent sloughing and necrosis in areas in with extravasation, infiltrate the area with an adrenergic blocking agent in saline. (5.1). oHypotension After Abrupt Discontinuation: Gradually taper norepinephrine infusion to prevent hypotension. (5.2). oCardiac Arrhythmias: Norepinephrine Bitartrate in Dextrose Injection may cause arrhythmias. Monitor cardiac function in patients with underlying heart disease. (5.3). 5.1 Tissue Ischemia Administration of Norepinephrine Bitartrate in Dextrose Injection 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 in Dextrose Injection [see Dosage and Administration (2.1)]. Avoid Norepinephrine Bitartrate in Dextrose Injection 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 in Dextrose Injection may cause necrosis and sloughing of surrounding tissue. To reduce the risk of extravasation, infuse into 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 ExtravasationTo prevent sloughing and necrosis in areas in which extravasation has occurred, infiltrate the ischemic area as soon as possible, using syringe with fine hypodermic needle with 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 in Dextrose Injection infusion rate while expanding blood volume with intravenous fluids.. 5.3 Cardiac Arrhythmias Norepinephrine Bitartrate in Dextrose Injection elevates intracellular calcium concentrations and may cause arrhythmias, particularly in the setting of hypoxia or hypercarbia. Perform continuous cardiac monitoring of patients with arrhythmias.