CSPT Sterile Compounding Calculations 4

Question 1

A pharmacist orders vancomycin 1250 mg in 500 mL NS to infuse over 90 minutes. What is the infusion rate in mL/hr?

Accepted Answer

333 mL/hr

Answer

500 mL ÷ 1.5 hr = 333 mL/hr.

Question 2

A TPN requires 50 g of dextrose. How many mL of D70W (70% dextrose) are needed?

Accepted Answer

71.4 mL

Answer

50 g ÷ 0.7 g/mL = 71.4 mL.

Question 3

A 1-liter bag of NS is infusing via gravity at 20 gtt/min with a 15 gtt/mL drip set. What is the infusion rate in mL/hr?

Accepted Answer

80 mL/hr

Answer

20 gtt/min ÷ 15 gtt/mL × 60 min/hr = 80 mL/hr.

Question 4

You are making a preparation requiring 0.8% benzalkonium chloride. How many mg are needed for 50 mL?

Accepted Answer

400 mg

Answer

0.8% = 0.8 g/100 mL = 0.4 g/50 mL = 400 mg.

Question 5

An antibiotic IVPB contains 750 mg in 100 mL. A dose of 500 mg is prescribed. How many mL should be administered?

Accepted Answer

66.7 mL

Answer

500 mg ÷ (750 mg/100 mL) = 66.7 mL.

CSPT - Compounded Sterile Preparation Technician Practice Test