What if we only have 8 mg of norepinephrine (Levophed) for dosing?

Using 8 mg of Norepinephrine for Infusion Preparation

If you only have 8 mg of norepinephrine available, dilute it in 500 mL of D5W to create a 16 mcg/mL concentration, which is the standard concentration recommended by guidelines and allows for appropriate dosing ranges. 1, 2

Standard Dilution Protocol

The FDA-approved preparation method calls for adding 4 mg of norepinephrine to 1,000 mL of 5% dextrose solution to yield 4 mcg/mL. 2 However, when working with 8 mg, you have two practical options:

Option 1: Standard Concentration (Recommended)

• Add 8 mg to 500 mL of D5W to create 16 mcg/mL concentration 1, 2
• This is the preferred alternative concentration cited in guidelines for standard use 1
• Provides adequate volume for typical infusion rates while maintaining stability 3

Option 2: Lower Concentration

• Add 8 mg to 2,000 mL of D5W to create 4 mcg/mL concentration 2
• This matches the FDA-recommended concentration exactly 2
• Use this approach if the patient requires large fluid volumes or prolonged therapy 2

Dosing Considerations With Your Preparation

Starting dose: Begin at 0.5-1 mL/min (8-16 mcg/min) if using the 16 mcg/mL concentration, which translates to approximately 0.1-0.2 mcg/kg/min for a 70 kg adult. 1, 2

Titration: Increase by 0.5 mg/h (approximately 8 mcg/min) every 4 hours as needed, up to a maximum of 3 mg/h (50 mcg/min). 1

Target: Maintain mean arterial pressure ≥65 mmHg or increase MAP by 10 mmHg from baseline. 1, 4

Critical Safety Points

• Always use dextrose-containing solutions (D5W or D5NS), never saline alone, as dextrose protects against oxidation and loss of potency 2, 3
• The prepared solution remains chemically stable for 7 days at room temperature under ambient light in either D5W or normal saline, though dextrose is preferred 3
• Administer through central venous access whenever possible to minimize extravasation risk 1, 2
• If extravasation occurs, immediately infiltrate phentolamine 5-10 mg diluted in 10-15 mL saline at the site 1

Volume Considerations

With only 8 mg available, your 500 mL bag will provide:

• Approximately 8 hours of therapy at moderate doses (0.1 mcg/kg/min for 70 kg patient = 7 mcg/min = 26 mL/h)
• Approximately 3-4 hours at higher doses (0.3 mcg/kg/min = 21 mcg/min = 79 mL/h)

Plan ahead: If the patient requires prolonged vasopressor support or high doses, prepare additional norepinephrine before the current bag is depleted to avoid interruption in therapy. 2

Special Circumstances

For anaphylaxis requiring norepinephrine infusion (after failed epinephrine): Use the alternative 1:100,000 dilution by adding 1 mg to 100 mL saline, administered at 30-100 mL/h (5-15 mcg/min). 1 With 8 mg available, you could prepare 8 separate 100 mL bags for this indication.

For refractory hypotension: When doses exceed 0.5 mcg/kg/min without adequate response, add vasopressin 0.03-0.04 units/min rather than continuing to escalate norepinephrine alone. 1, 4