What is the FDA label indication for norepinephrine (Levophed) in treating hypotension?

FDA Label Indication for Norepinephrine (Levophed) in Treating Hypotension

Norepinephrine (Levophed) is FDA-indicated for restoration of blood pressure in acute hypotensive states, particularly when volume replacement alone is insufficient to maintain adequate perfusion to vital organs. 1

Primary Indications

Norepinephrine is specifically indicated for:

• Restoration of blood pressure in acute hypotensive states
• Management of hypotension with low peripheral vascular resistance (systolic BP ≤70 mmHg)
• Adjunctive treatment during cardiac arrest to maintain blood pressure after effective heartbeat and ventilation have been established

Administration Guidelines

Dosing

• Initial dose: 2-3 mL (8-12 mcg of base) per minute
• Average maintenance dose: 0.5-1 mL (2-4 mcg of base) per minute
• Typical starting dose range: 0.1-0.5 mcg/kg/min (7-35 mcg/min in a 70-kg adult) 2, 3
• Titrate according to patient response to establish and maintain low normal blood pressure (usually 80-100 mmHg systolic) 1

Blood Pressure Targets

• In previously normotensive patients: Maintain MAP ≥65 mmHg
• In previously hypertensive patients: Raise blood pressure no higher than 40 mmHg below preexisting systolic pressure 1

Administration Route

• Preferred route: Central venous catheter to minimize risk of extravasation 3, 1
• Alternative when central access unavailable: Large peripheral vein using a microdrip system with careful monitoring for extravasation 3

Important Contraindications

Norepinephrine should NOT be given to:

1. Patients hypotensive from blood volume deficits except as an emergency measure until volume replacement can be completed 1
2. Patients with mesenteric or peripheral vascular thrombosis (risk of extending ischemia/infarction) unless as a life-saving measure 1
3. During cyclopropane or halothane anesthesia (risk of ventricular arrhythmias) 1
4. Patients with profound hypoxia or hypercarbia (risk of cardiac arrhythmias) 1

Clinical Considerations and Precautions

Volume Status

• Ensure adequate fluid resuscitation before or concurrent with norepinephrine initiation
• Occult blood volume depletion should always be suspected and corrected when present 1
• Central venous pressure monitoring is helpful in detecting and treating volume depletion 1

Extravasation Management

• If extravasation occurs, infiltrate the area with 5-10 mg of phentolamine diluted in 10-15 mL of saline as soon as possible to prevent tissue necrosis 2, 3

Weaning

• Reduce infusion gradually, avoiding abrupt withdrawal 1
• In some cases of vascular collapse due to acute myocardial infarction, treatment may be required for up to six days 1

Special Considerations

• Norepinephrine is relatively contraindicated in patients with hypovolemia as it may increase myocardial oxygen requirements 2
• It typically induces renal and mesenteric vasoconstriction; however, in septic shock, norepinephrine may actually improve renal blood flow and urine output 2
• Early administration of norepinephrine in septic shock has been associated with improved shock control and reduced fluid requirements 4, 5, 6
• Avoid mixing with sodium bicarbonate or other alkaline solutions in the IV line, as adrenergic agents can be inactivated in alkaline solutions 3

By following these guidelines, clinicians can appropriately use norepinephrine to treat hypotension while minimizing potential adverse effects and optimizing patient outcomes.