PTCB Sterile Compounding & Pharmacy Calculations 2 — Questions and Answers
Question 1: What does tonicity refer to in the context of IV fluids?
- The pH of the solution
- The osmotic pressure of a solution relative to blood plasma (Correct answer)
- The viscosity of the fluid
- The temperature of the solution
Correct answer: The osmotic pressure of a solution relative to blood plasma
Tonicity describes the effective osmotic pressure of a solution relative to plasma (approximately 285–295 mOsm/kg), determining its effect on cell volume.
Question 2: If an order reads 'KCl 40 mEq in 100 mL NS,' what type of solution is this considered?
- Large-volume parenteral (LVP)
- Small-volume parenteral (SVP) (Correct answer)
- Total parenteral nutrition (TPN)
- Ophthalmic solution
Correct answer: Small-volume parenteral (SVP)
Preparations ≤250 mL are classified as small-volume parenterals (SVPs), commonly called 'piggybacks' (IVPBs).
Question 3: How many micrograms are in 1 milligram?
- 10 mcg
- 100 mcg
- 1,000 mcg (Correct answer)
- 10,000 mcg
Correct answer: 1,000 mcg
There are 1,000 micrograms (mcg) in 1 milligram (mg).
Question 4: A drip order is for 500 mL over 4 hours with a drop factor of 20 gtts/mL. What is the drip rate?
- 25 gtts/min
- 42 gtts/min (Correct answer)
- 60 gtts/min
- 83 gtts/min
Correct answer: 42 gtts/min
(500 mL × 20 gtts/mL) ÷ (4 hr × 60 min/hr) = 10,000 ÷ 240 ≈ 41.7 ≈ 42 gtts/min.
Question 5: What PPE is required when handling hazardous drugs during compounding?
- Gloves only
- Gown only
- Double gloves, gown, eye protection, and respiratory protection as needed (Correct answer)
- Standard lab coat and single gloves
Correct answer: Double gloves, gown, eye protection, and respiratory protection as needed
USP <800> requires double gloves, a chemotherapy-rated gown, eye/face protection, and respiratory protection when handling hazardous drugs.
Question 6: A 1:1000 epinephrine solution contains how many mg per mL?
- 0.01 mg/mL
- 0.1 mg/mL
- 1 mg/mL (Correct answer)
- 10 mg/mL
Correct answer: 1 mg/mL
A 1:1000 ratio means 1 g per 1,000 mL = 1 mg/mL.
PTCB Sterile Compounding & Pharmacy Calculations 2
What does tonicity refer to in the context of IV fluids?