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 agonist activity (inotropic effect). It is the first-line vasopressor for septic and vasodilatory shock.
## Primary Indications
* Acute hypotensive states (e.g., septic shock, cardiogenic shock).
* Adjunct in the treatment of cardiac arrest (less common than epinephrine).
## Adult Dosing
* **Initial Infusion:** 0.01–0.05 mcg/kg/min (or 5–10 mcg/min flat rate) titrated to achieve target mean arterial pressure (MAP).
* **Maintenance:** 0.01–3 mcg/kg/min.
* **Dosing note:** Protocols vary by institution; always consult local standard orders for concentration and titration intervals.
## Pediatric Dosing
* **Initial Infusion:** 0.05–0.1 mcg/kg/min.
* **Titration:** Titrate by 0.05–0.1 mcg/kg/min to meet hemodynamic goals.
* **Maximum:** Generally up to 2 mcg/kg/min; consult pediatric intensive care guidelines.
## Dose Adjustments
* **Renal/Hepatic:** No specific dose adjustments provided; titrate to clinical effect.
* **Discontinuation:** Wean gradually to prevent rebound hypotension.
## Contraindications
* Hypersensitivity to norepinephrine.
* Hypotension due to uncorrected blood volume deficit (except as emergency support until volume replacement is complete).
* Mesenteric or peripheral vascular thrombosis (due to severe vasoconstriction).
## Adverse Effects
* **Common:** Hypertension, headache, anxiety.
* **Severe:** Tissue necrosis due to extravasation, bradycardia (reflex), arrhythmias, mesenteric/peripheral ischemia, lactic acidosis.
* **Extravasation Management:** Stop infusion immediately. If extravasation occurrs, infiltrate the area with phentolamine (alpha-blocker) promptly to prevent sloughing/necrosis.
## Key Drug Interactions
* **MAOIs / TCAs:** May result in severe, prolonged hypertension.
* **Beta-blockers:** May cause excessive peripheral vasoconstriction and reflex bradycardia.
* **Halogenated Hydrocarbons (e.g., volatile anesthetics):** May render the heart hypersensitive to catecholamines, increasing arrhythmia risk.
## Monitoring
* **Continuous:** Arterial pressure (preferred), heart rate, ECG (for arrhythmias).
* **Perfusion:** MAP targets, urine output, skin temperature, serum lactate, and capillary refill.
* **Access site:** Frequent assessment for signs of extravasation (palpate for firmness/coolness).
## Clinical Pearls
* **Central Access:** Highly recommended. Peripheral administration is acceptable only if strictly necessary and for a limited duration via a large-bore proximal vein to mitigate extravasation risk.
* **Fluid Status:** Vasopressors are not a substitute for effective volume resuscitation. Ensure adequate fluid therapy in hypovolemic patients.
* **Titration:** Norepinephrine has a very short half-life (~2–3 minutes), requiring rapid titration and close monitoring.
***
*Disclaimer: This information is for educational purposes and does not replace professional clinical judgment. Always verify dosages, contraindications, and drug compatibility against institutional protocols and current product labeling before prescribing or administering.*
