Nor%2525252525252520epinephrine

# Norepinephrine ## Overview Norepinephrine is a potent catecholamine acting primarily as an alpha-1 adrenergic agonist (vasoconstriction) with moderate beta-1 adrenergic 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). * Cardiac arrest (less common, usually second-line). ## Adult Dosing * **Initial:** 0.05–0.1 mcg/kg/min continuous IV infusion. * **Titration:** Titrate to achieve target Mean Arterial Pressure (MAP), typically ≥65 mmHg. * **Maintenance:** 0.01–3 mcg/kg/min. * **Maximum:** No established federal limit; limited by systemic vasoconstriction, tissue ischemia, and refractory tachyarrhythmias. Infusions at >1 mcg/kg/min often necessitate the addition of a second agent (e.g., vasopressin). ## Pediatric Dosing * **Initial:** 0.05–0.1 mcg/kg/min continuous IV infusion. * **Titration:** Titrate by 0.05–0.1 mcg/kg/min every 5–15 minutes based on hemodynamic response. * **Maintenance/Range:** 0.05–2 mcg/kg/min. * *Note: Dosing is highly dependent on institutional protocols and local pediatric intensive care guidelines.* ## Dose Adjustments * **Renal/Hepatic:** No specific dose adjustment defined; however, cautious titration is required as patients with organ failure may exhibit altered pharmacodynamics. * **Volume Status:** Efficacy is significantly reduced in hypovolemic patients; ensure adequate fluid resuscitation prior to or concurrent with initiation. ## Contraindications * Hypersensitivity to norepinephrine or bisulfites. * Hypovolemia (without concomitant fluid replacement). * Mesenteric or peripheral vascular thrombosis (due to risk of increasing ischemia). ## Adverse Effects * **Cardiovascular:** Hypertension, bradycardia (reflex), tachyarrhythmias, myocardial ischemia. * **Dermatologic:** Extravasation can cause severe tissue necrosis and sloughing (treat with phentolamine infiltration if local protocol permits). * **Peripheral:** Digital ischemia, limb gangrene. * **Metabolic:** Hyperglycemia, metabolic acidosis. ## Key Drug Interactions * **MAO Inhibitors / TCAs:** May cause severe, prolonged hypertension. * **Beta-Blockers:** May trigger unopposed alpha-mediated vasoconstriction, leading to severe hypertension and reflex bradycardia. * **Anesthetics (Halogenated):** Increased risk of ventricular arrhythmias. ## Monitoring * **Hemodynamics:** Continuous invasive arterial pressure monitoring is preferred. * **Cardiac:** Continuous ECG monitoring for arrhythmias. * **Access Site:** Assess infusion site frequently for signs of extravasation (pallor, coldness). * **End-Organ Perfusion:** Urine output, serum lactate, and peripheral perfusion (capillary refill, extremity warmth). ## Clinical Pearls * **Central Line:** Must be administered via a large-bore central venous catheter (CVC) whenever possible to minimize risk of extravasation necrosis. * **Weaning:** Wean slowly to avoid abrupt hemodynamic collapse. * **Compatibility:** Highly acidic; check Y-site compatibility as it is incompatible with many common drugs (e.g., sodium bicarbonate, insulin). * **Concentration:** Standardize concentrations (e.g., 4mg/250mL or 8mg/250mL) per institutional policy to reduce medication errors. *** *Disclaimer: This information is for educational purposes only. Clinical practice varies by institution. Always verify specific dosing, safety protocols, and drug compatibility via current hospital-approved formulary references and recent prescribing information.*