Please check your internet connection and try again.
# Norepinephrine
## Overview
Norepinephrine is a potent catecholamine with primary alpha-1 adrenergic agonist activity (vasoconstriction) and moderate beta-1 adrenergic activity (inotropic effect). It is the first-line vasopressor for septic shock.
## Primary Indications
* Acute hypotension (e.g., septic, cardiogenic, or neurogenic shock)
* Adjunct treatment during cardiac arrest
## Adult Dosing
* **Initial:** 0.01–0.05 mcg/kg/min (or 5–30 mcg/min).
* **Titration:** Titrate to achieve target Mean Arterial Pressure (MAP), typically ≥65 mmHg.
* **Maintenance:** Usual range is 0.05–0.5 mcg/kg/min.
* **Maximum:** Doses exceeding 1–3 mcg/kg/min are occasionally used in refractory shock but carry significant risk of severe peripheral ischemia.
## Pediatric Dosing
* **Continuous Infusion:** 0.05–0.5 mcg/kg/min.
* **Note:** Dosing varies by institutional protocol and clinical acuity. Always verify weight-based calculations using a standardized concentration (often 0.1 mg/mL or 0.5 mg/mL) to prevent dosing errors.
## Dose Adjustments
* No specific renal or hepatic dosage adjustments defined; titration is purely physiologic based on hemodynamic response.
* **Geriatric:** Use the lowest effective dose; monitor closely for cardiac arrhythmias.
## Contraindications
* Hypotension due to uncorrected hypovolemia (must restore volume status first).
* Hypersensitivity to norepinephrine or sulfites (some formulations contain sodium metabisulfite).
## Adverse Effects
* **Extravasation:** Severe tissue necrosis and sloughing; treat with phentolamine infiltration.
* **Cardiovascular:** Hypertension, bradycardia (reflex), arrhythmias, myocardial ischemia.
* **Endocrine/Metabolic:** Hyperglycemia.
* **Peripheral:** Digital/limb ischemia.
## Key Drug Interactions
* **MAO Inhibitors / TCAs:** May cause severe, prolonged hypertension.
* **Alpha/Beta-blockers:** May antagonize the vasoconstrictive effects of norepinephrine.
* **Inhalation Anesthetics:** May increase myocardial sensitivity to catecholamines, increasing arrhythmia risk.
## Monitoring
* **Hemodynamics:** Continuous intra-arterial blood pressure monitoring (preferred).
* **Perfusion:** Mental status, urine output, lactate levels, central venous oxygen saturation (ScvO2).
* **Site:** Hourly inspection of the infusion site for signs of extravasation.
* **ECG:** Continuous monitoring for arrhythmias.
## Clinical Pearls
* **Central Access:** Must be administered via a large peripheral vein (only for short-term use in emergencies) or ideally a central venous catheter to minimize extravasation risk.
* **Compatibility:** Highly acidic; check compatibility before Y-site administration. Typically diluted in D5W or NS (D5W preferred to prevent oxidation).
* **Weaning:** Wean gradually to prevent rapid hemodynamic collapse; ensure volume optimization before final discontinuation.
* **Refractory Shock:** If requiring high doses, evaluate for adrenal insufficiency or need for adjunctive vasopressors (e.g., vasopressin).
***
**Educational Disclaimer:** This information is for educational purposes only. Clinical practice is subject to institutional guidelines and evolving evidence. Always verify drug doses, compatibility, and infusion concentrations against your facility’s current protocols and the official manufacturer prescribing information before administration.
