Norepinephrine (Noradrenaline — Perioperative Vasopressor)

SCOPE: this draft covers the page's primary use - norepinephrine given as a continuous intravenous vasopressor infusion titrated to blood pressure, which is exactly what this label doses. The label is written for acute hypotension generally and carries no separate perioperative, obstetric-spinal or septic-shock regimen, so none is published here. || Highlights line (section 2.2) verbatim: '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 )'. WARNING - INTERNAL INCONSISTENCY IN THE LABEL ITSELF: those millilitre volumes do not correspond to the dilution the same label prepares in section 2.3 (4 mcg per mL). Dividing the label's own paired figures (8 mcg by 0.25 mL, and equally 2 mcg by 0.0625 mL) gives 32 mcg per mL - that ratio is arithmetic from the label's two figures, NOT a strength printed anywhere in the label, and it is eight times the prepared dilution. Dose in micrograms per minute and do not use the millilitre figures as a volume instruction. || BEFORE STARTING (section 2.1 verbatim): 'Address hypovolemia before initiation of norepinephrine bitartrate injection therapy. If the patient does not respond to therapy, suspect occult hypovolemia.' || PREPARATION (section 2.3 verbatim): '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.' Diluted solution may be stored up to 24 hours at 20 C to 25 C, protected from light. Do not use if the solution is pinkish, darker than slightly yellow, or contains a precipitate. || STRENGTH (section 3 verbatim): 'Injection: 4 mg/4 mL (1 mg/mL norepinephrine base) sterile, clear, colorless to slightly yellow solution in a single-dose amber glass vial.' || EXTRAVASATION (section 5.1 verbatim): '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.' The label does not name a specific agent, and no named agent is added here. || INCOMPATIBILITIES (section 2.4 verbatim): 'Avoid contact with iron salts, alkalis, or oxidizing agents. Whole blood or plasma, if indicated to increase blood volume, should be administered separately.' || ELDERLY (section 8.5): '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... Avoid administration of norepinephrine bitartrate into the veins in the leg in elderly patients.' || INTERACTIONS (section 7): MAO inhibitors or other drugs with MAO-inhibiting properties (e.g. linezolid) and tricyclic antidepressants (amitriptyline, nortriptyline, protriptyline, clomipramine, desipramine, imipramine) 'can cause severe, prolonged hypertension'; halogenated anaesthetics (cyclopropane, desflurane, enflurane, isoflurane, sevoflurane) 'increase cardiac autonomic irritability'; norepinephrine 'can decrease insulin sensitivity and raise blood glucose'. || PAEDIATRIC (section 8.4 verbatim): 'Safety and effectiveness in pediatric patients have not been established.' paedDose is therefore null - verify any under-18 use against a children's formulary. || This is US labelling only; confirm against UK product literature before UK use.