Nicardipine Drip Calculation
For a nicardipine concentration of 50 mg in 250 mL D5W (0.2 mg/mL), to deliver 5 mg/hour, set the infusion pump to 25 mL/hour.
Calculation Method
The formula is straightforward:
mL/hour = (Desired dose in mg/hour) ÷ (Concentration in mg/mL)
For your specific preparation:
- Concentration: 50 mg ÷ 250 mL = 0.2 mg/mL
- Desired dose: 5 mg/hour
- Infusion rate: 5 mg/hour ÷ 0.2 mg/mL = 25 mL/hour
Standard Dosing Context
According to FDA labeling, nicardipine IV should be initiated at 5 mg/hour in drug-free patients 1. This starting dose aligns with guideline recommendations for hypertensive emergencies, where nicardipine is typically started at 5 mg/hour and titrated by 2.5 mg/hour increments every 5-15 minutes to a maximum of 15 mg/hour until blood pressure goals are achieved 2, 1.
Titration Schedule
- For gradual BP reduction: Increase by 2.5 mg/hour every 15 minutes
- For rapid BP reduction: Increase by 2.5 mg/hour every 5 minutes
- Maximum dose: 15 mg/hour 1
Once therapeutic response is achieved, the maintenance infusion typically ranges from 3-5 mg/hour 1.
Common Concentration Conversions
For the 50 mg/250 mL preparation (0.2 mg/mL):
- 5 mg/hour = 25 mL/hour
- 7.5 mg/hour = 37.5 mL/hour
- 10 mg/hour = 50 mL/hour
- 12.5 mg/hour = 62.5 mL/hour
- 15 mg/hour = 75 mL/hour
Critical Safety Considerations
Change the infusion site every 12 hours to minimize risk of peripheral venous irritation and phlebitis 1. Avoid small veins such as those on the dorsum of the hand or wrist 1.
Monitor for hypotension (5% incidence) and reflex tachycardia (4% incidence) 1. If either occurs, discontinue the infusion and restart at lower doses (3-5 mg/hour) once stabilized 1.
The mean time to therapeutic response in severe hypertension is approximately 77 minutes at average maintenance doses of 8 mg/hour, while postoperative hypertension responds within 12 minutes at average maintenance doses of 3 mg/hour 1.