Norad%2520%2528norepinephrine%2529

# Norad (norepinephrine) ## Overview Norepinephrine is a direct-acting sympathomimetic amine that primarily stimulates alpha-1 receptors, causing potent vasoconstriction, with modest beta-1 activity. It is used as a first-line vasopressor for shock. ## Primary Indications - Septic shock (first-line vasopressor) - Cardiogenic shock (if hypotension persists after fluids/other agents) - Other distributive shock states (e.g., neurogenic, anaphylactic) ## Adult Dosing - **Initial**: 0.5–1 mcg/min by continuous IV infusion, titrate to effect (typically target MAP ≥65 mm Hg). - **Usual range**: 2–30 mcg/min. Doses >30 mcg/min may be used but with caution; consider adding a second vasopressor if high doses are needed. - **Maximum**: No absolute maximum; however, escalating doses beyond 30–50 mcg/min often require additional agents. - *Note: Exact dosing depends on local protocol, hemodynamic goals, and patient response.* ## Pediatric Dosing - **Initial**: 0.05–0.1 mcg/kg/min continuous IV infusion. - **Titrate** by 0.05–0.1 mcg/kg/min every 5–10 minutes to target MAP (age-dependent) or clinical perfusion. - **Usual maximum**: 0.5–2 mcg/kg/min (higher doses may be used in resuscitation, but evidence limited). - *Dosing per local protocol; weight-based dosing mandatory.* ## Dose Adjustments - **Renal impairment**: No dose adjustment needed. - **Hepatic impairment**: No specific guidelines; monitor for excessive vasoconstriction. - **Elderly**: Start at low end of dosing range due to increased sensitivity. ## Contraindications - Hypersensitivity to norepinephrine or any component. - Hypotension from hypovolemia (except as temporary measure until volume resuscitation). - Peripheral vascular thrombosis or mesenteric vascular occlusion (relative; risk of ischemia). - Uncontrolled hyperthyroidism or severe hypertension (relative). ## Adverse Effects - **Common**: Hypertension, bradycardia (reflex), tachycardia (beta effect), headache, anxiety. - **Serious**: Peripheral ischemia/extravasation injury (treat with phentolamine 5–10 mg in 10–15 mL saline infiltrated), arrhythmias, reduced cardiac output (high doses), tissue necrosis from prolonged use. - **Organ-specific**: Mesenteric/renal ischemia (especially at high doses or prolonged use). ## Key Drug Interactions - MAO inhibitors (MAOIs) – may cause severe hypertensive crisis. - Tricyclic antidepressants – enhance pressor response; use lower starting doses. - Beta-blockers – unopposed alpha activity can lead to severe hypertension. - Other vasopressors/ergot alkaloids – additive vasoconstriction; increased risk of ischemia. - Halogenated anesthetics – may sensitize myocardium to arrhythmias. ## Monitoring - **Continuous**: Blood pressure (preferably arterial line), heart rate, ECG, infusion site for extravasation. - **Periodic**: Cardiac output (if available), urine output, distal perfusion (capillary refill, skin mottling), metabolic status (lactate). - **Central line**: Strongly preferred for administration; peripheral use should be limited (<2 hours) and in large vein to reduce extravasation risk. ## Clinical Pearls - Norepinephrine is the first-line vasopressor in septic shock (Surviving Sepsis Campaign). - Always correct hypovolemia first, but do not delay vasopressor in profound hypotension. - Extravasation: Antidote is phentolamine; infiltrate within 12 hours. - Withdraw slowly to avoid rebound hypotension; do not stop abruptly. - High doses (>30 mcg/min) often indicate need for additional vasopressin or inotrope (e.g., dobutamine). --- *Educational disclaimer: This information is for educational purposes and is not a substitute for professional medical judgment. Always verify dosing against current institutional protocols, drug labeling, and patient-specific factors before administration.*