First, convert micrograms per minute (mcg/min) to milligrams per hour (mg/hr).
- D = Dose (mcg)
Then use the dosage formula to calculate rate.
- O = Dose ordered
- V = Volume of dose available
- A = Dose available
1. Start an infusion of nitroglycerin at 10 mcg/min, then titrate to chest pain. The nitroglycerin is to be mixed as 50 mg in 250 milliliters (mL) of D5W. First, convert mcg/min to mg/hr.
- Dose (mcg) = 10 mcg
The answer is 0.6 mg/hr. Then use the dosage formula. To complete the problem
- Dose ordered (mg) = 0.6 mg
- Volume of dose available (mL) = 250 mL
- Dose available (mg) = 50 mg
The answer is 3 mL/hr.
2. Start an infusion of Levophed® (norepinephrine) at 4 mcg/min then titrate to blood pressure. Pharmacy has mixed 4 mg of Levophed® in a 1,000 mL bag of D5W. First, convert mcg/min to mg/hr.
- Dose (mcg) = 4 mcg
The answer is 0.24 mg/hr. Then use the dosage formula. To complete the problem
- Dose ordered = 0.24 mg
- Volume of dose available = 1000 mL
- Dose available = 4 mg
The answer is 60 mL/hr.