Please check your internet connection and try again.
# Norepinephrine
## Overview
Norepinephrine is a potent vasopressor and inotrope that acts primarily on alpha-1 adrenergic receptors, causing vasoconstriction and increasing systemic vascular resistance. It also has some beta-1 adrenergic activity, leading to increased myocardial contractility.
## Primary Indications
* Severe hypotension and shock, particularly distributive shock (e.g., septic shock, neurogenic shock).
* Cardiogenic shock (adjunct therapy).
## Adult Dosing
* **Initiation:** Typically 0.01 to 0.02 mcg/kg/min IV.
* **Titration:** Titrate infusion rate to achieve target mean arterial pressure (MAP) of 65 mmHg or higher, or as per local protocol. Doses can range from 0.01 to 2 mcg/kg/min IV, and occasionally higher in refractory shock.
## Pediatric Dosing
* **Initiation:** 0.05 to 0.1 mcg/kg/min IV.
* **Titration:** Titrate to desired hemodynamic effect, typically targeting MAP ≥ gestational age + 2 mmHg for neonates, or MAP ≥ 50 mmHg in older children. Doses can range from 0.05 to 2 mcg/kg/min IV.
## Dose Adjustments
No specific dose adjustments for renal or hepatic impairment are established. Dosing is primarily guided by hemodynamic response.
## Contraindications
* Hypersensitivity to norepinephrine.
* Hypotensive patients with mechanical obstruction of cardiac filling or outflow.
## Adverse Effects
* Hypertension, reflex bradycardia, arrhythmias.
* Peripheral ischemia, tissue necrosis at infusion site (extravasation).
* Headache, anxiety, dizziness.
* Pulmonary edema.
## Key Drug Interactions
* **MAO Inhibitors:** Potentiate hypertensive crisis; avoid concurrent use or use with extreme caution.
* **Tricyclic Antidepressants:** Potentiate hypertensive effects.
* **Beta-blockers:** May blunt the inotropic effects of norepinephrine and potentially lead to unopposed alpha-receptor stimulation (vasoconstriction).
* **Anesthetics:** May increase myocardial irritability and risk of arrhythmias.
## Monitoring
* Continuous ECG and blood pressure monitoring.
* Central venous pressure (CVP) and pulmonary artery pressures if available.
* Urine output.
* Peripheral perfusion (skin temperature, color, capillary refill).
* Infusion site for signs of extravasation.
## Clinical Pearls
* Norepinephrine is a potent vasoconstrictor and must be administered via a central venous catheter to minimize the risk of extravasation and tissue necrosis.
* If extravasation occurs, discontinue the infusion and administer phentolamine to the affected area.
* Short-term use is preferred; prolonged infusions may require careful consideration of risks and benefits.
* The choice of vasoactive agent in shock is often guided by the underlying cause and may involve combinations of drugs.
***
*This information is intended for healthcare professionals. Always consult the official prescribing information and relevant clinical guidelines for complete and up-to-date details before making any treatment decisions.*
