CSPT Compounding Calculations 2

Question 1

A pharmacist orders 1 L of a 0.9% NaCl solution. How many grams of NaCl are needed?

Accepted Answer

9 g

Answer

0.9% w/v means 0.9 g per 100 mL, so 1000 mL × 0.009 g/mL = 9 g.

Question 2

You need to prepare 250 mL of a 2% lidocaine solution from a 4% stock. How much 4% stock is needed?

Accepted Answer

125 mL

Answer

Using C1V1=C2V2: 4% × V1 = 2% × 250 mL → V1 = 125 mL.

Question 3

An order calls for heparin 25,000 units in 250 mL D5W. What is the concentration in units/mL?

Accepted Answer

100 units/mL

Answer

25,000 units ÷ 250 mL = 100 units/mL.

Question 4

A TPN requires 500 mL of 50% dextrose. How many grams of dextrose does this provide?

Accepted Answer

250 g

Answer

50% w/v = 50 g/100 mL; 50 g/100 mL × 500 mL = 250 g.

Question 5

A patient requires dopamine at 5 mcg/kg/min. Weight is 80 kg. The bag contains 400 mg/250 mL. What is the infusion rate in mL/hr?

Accepted Answer

7.5 mL/hr

Answer

Dose = 5 × 80 = 400 mcg/min = 0.4 mg/min; concentration = 400 mg/250 mL = 1.6 mg/mL; rate = 0.4/1.6 = 0.25 mL/min × 60 = 15 mL/hr — wait, let me recalculate: 400 mcg/min ÷ 1600 mcg/mL = 0.25 mL/min × 60 = 15 mL/hr.

CSPT - Compounded Sterile Preparation Technician Practice Test

CSPT - Compounded Sterile Preparation Technician Practice Test

CSPT Compounding Calculations 2