Please check your internet connection and try again.
# Norepinephrine
## Overview
Norepinephrine is a potent catecholamine with primary alpha-1 adrenergic agonist activity (vasoconstriction) and secondary beta-1 adrenergic agonist activity (inotropic effect). It is the first-line vasopressor for septic shock.
## Primary Indications
* Acute hypotensive states (e.g., septic shock, cardiogenic shock).
* Adjunctive therapy in cardiac arrest.
## Adult Dosing
* **Initial:** 0.01 to 0.05 mcg/kg/min (or 5–20 mcg/min).
* **Titration:** Titrate to clinical effect, typically targeting a Mean Arterial Pressure (MAP) of 65 mmHg.
* **Maintenance:** 0.01 to 3 mcg/kg/min; some refractory cases may require higher doses, though this increases the risk of ischemia.
* *Note:* Dosing is highly dependent on institutional hemodynamic protocols.
## Pediatric Dosing
* **Initial:** 0.05 to 0.1 mcg/kg/min.
* **Titration:** Titrate by 0.05 mcg/kg/min every 5–15 minutes as needed.
* **Maximum:** Up to 2 mcg/kg/min.
* *Note:* Central venous access is strongly preferred in neonates/pediatrics to minimize extravasation risk.
## Dose Adjustments
* **Renal/Hepatic Impairment:** No formal dose adjustments; however, patients may be more sensitive to pressor effects.
* **Weaning:** When stabilizing, titrate down slowly to avoid precipitous drops in blood pressure.
## Contraindications
* Hypersensitivity to norepinephrine or sulfite-containing products.
* Do not administer via peripheral line if avoidable (high risk of tissue necrosis).
* Severe hypoxia or hypercapnia (may exacerbate cardiac arrhythmias).
## Adverse Effects
* **Common:** Hypertension, headache, anxiety.
* **Serious:** Reflex bradycardia, cardiac arrhythmias (tachycardia/VT), limb ischemia, mesenteric ischemia.
* **Extravasation:** Severe focal tissue necrosis/sloughing (treat with phentolamine infiltration if occurs).
## Key Drug Interactions
* **MAO Inhibitors / TCAs:** May result in severe, prolonged hypertension.
* **Beta-Blockers:** May interfere with the beta-1 compensatory effects, potentially leading to unopposed alpha-mediated vasoconstriction.
* **Halogenated hydrocarbons (e.g., cyclopropane, halothane):** Increase myocardial sensitivity to catecholamines, elevating arrhythmia risk.
## Monitoring
* **Continuous:** ECG monitoring for arrhythmias and invasive arterial blood pressure monitoring (recommended).
* **Fluid Status:** Ensure patient is adequately resuscitated; norepinephrine is ineffective in profound hypovolemia.
* **Perfusion:** Monitor peripheral pulses, skin temperature, and urine output.
* **Infusion Site:** Monitor for infiltration or blanching, especially if peripheral access is used.
## Clinical Pearls
* **Extravasation Management:** If extravasation occurs, discontinue infusion and infiltrate the site with phentolamine 5–10 mg in 10 mL saline as soon as possible.
* **Efficacy:** Superiority over dopamine has been demonstrated in septic shock outcomes.
* **Potency:** Extremely potent; always use an infusion pump. Never bolus the concentrated stock solution.
***
**Educational Disclaimer:** This information is for educational purposes only. Always consult your institutional protocols, local formulary, and the most current prescribing information (e.g., package insert) before clinical application.
