Please check your internet connection and try again.
# Norepinephrine
## Overview
Norepinephrine is a potent catecholamine with primary alpha-1 agonist activity (vasoconstriction) and secondary beta-1 agonist activity (inotropic effect). It is the first-line vasopressor for septic shock.
## Primary Indications
* Acute hypotension (e.g., septic shock, cardiogenic shock).
* Adjunct treatment of cardiac arrest.
## Adult Dosing
* **Shock:** Start at 0.01–0.05 mcg/kg/min (or 2–4 mcg/min fixed dose). Titrate by 0.05–0.1 mcg/kg/min every 2–5 minutes to reach target MAP (typically 65 mmHg).
* **Usual Maintenance Range:** 0.05–0.5 mcg/kg/min.
* **Max Dose:** No specific therapeutic ceiling; refractory cases may require doses >3 mcg/kg/min, though high-dose therapy is associated with increased mortality and limb ischemia.
## Pediatric Dosing
* **Shock:** Start at 0.05–0.1 mcg/kg/min.
* **Titration:** Increase in increments of 0.05–0.1 mcg/kg/min as needed.
* **Max Dose:** Generally up to 1 mcg/kg/min.
* *Note: Always consult institutional guidelines for pediatric weight-based titrations and concentration standards.*
## Dose Adjustments
* **Renal/Hepatic Impairment:** No specific standard dose adjustments required, but monitor for altered pharmacokinetics in multi-organ failure.
* **Discontinuation:** Taper slowly to prevent rebound hypotension.
## Contraindications
* Hypersensitivity to norepinephrine or bisulfites.
* Use as the sole agent in hypovolemic shock (must restore intravascular volume first).
## Adverse Effects
* **Cardiovascular:** Tachyarrhythmias, bradycardia (reflex), myocardial ischemia, hypertension.
* **Local:** Extravasation can lead to severe tissue necrosis and sloughing (treat with phentolamine infiltration).
* **Other:** Peripheral ischemia (fingers/toes).
## Key Drug Interactions
* **MAO Inhibitors/TCAs:** Risk of severe, prolonged hypertension; dose reduction of norepinephrine required.
* **Beta-Blockers:** May lead to unopposed alpha-adrenergic stimulation, increasing risk of hypertension and reflex bradycardia.
* **General Anesthetics:** (e.g., halothane, cyclopropane) May sensitize the myocardium to arrhythmias.
## Monitoring
* Continuous invasive blood pressure monitoring (A-line preferred).
* Heart rate and continuous ECG for arrhythmia detection.
* Peripheral perfusion check (capillary refill, skin temperature).
* Urine output.
* Monitor IV site closely for signs of extravasation.
## Clinical Pearls
* **Administration:** Must be administered via a **central venous catheter** whenever possible to minimize risk of extravasation; avoid peripheral administration unless necessary, and only for short durations through a large-bore proximal vein.
* **Compatibility:** Highly acidic; check compatibility before Y-site administration.
* **Local Protocol:** Titration increments and starting doses are highly dependent on institutional sepsis and shock protocols.
***
*Disclaimer: This information is for educational purposes only. Clinical practice varies by institution. Always verify dosages, contraindications, and compatibility with current local hospital protocols and official prescribing information before administration.*
