Nicardipine Infusion Rate Calculation
To deliver 5 mg per hour from a solution containing 25 mg in 240 mL, you need to infuse at 48 mL per hour.
Calculation Method
The concentration of your diluted solution is:
- 25 mg ÷ 240 mL = 0.104 mg/mL (approximately 0.1 mg/mL)
To deliver 5 mg per hour:
- 5 mg/hr ÷ 0.104 mg/mL = 48 mL/hr
This matches the standard nicardipine dilution protocol where each 25 mg vial is diluted in 240 mL of compatible IV fluid to yield 250 mL total volume at a concentration of 0.1 mg/mL 1.
Clinical Context for Nicardipine Dosing
For initiating therapy in acute hypertension, start at 5 mg/hr (50 mL/hr with standard 0.1 mg/mL concentration). If desired blood pressure reduction is not achieved, increase by 2.5 mg/hr every 15 minutes up to a maximum of 15 mg/hr 1. For more rapid blood pressure reduction, you can titrate every 5 minutes 1.
Key Dosing Parameters:
- Initial rate: 5 mg/hr for gradual BP reduction
- Titration increments: 2.5 mg/hr every 15 minutes (or every 5 minutes for rapid control)
- Maximum rate: 15 mg/hr
- Maintenance: Typically 3-8 mg/hr once therapeutic response achieved 1, 2
Important Safety Considerations:
Change the infusion site every 12 hours when administering via peripheral vein to prevent phlebitis 1. The incidence of local phlebitis increases significantly after 14 hours of infusion at a single site 3.
Monitor blood pressure and heart rate continuously during infusion. Expect a reflex increase in heart rate of approximately 5-10 beats per minute 3, 4. Blood pressure begins to fall within minutes, reaching approximately 50% of ultimate decrease in about 45 minutes with constant infusion 1.