Dosage Calculations Flashcards
7 cards from real CPHT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Dosage Calculations flashcards as text
A pharmacist prepares 120 mL of a 5% dextrose solution using a 50% dextrose stock. How many mL of the 50% stock are needed?
Answer: 12 mL
Using C1V1 = C2V2: 50% × V1 = 5% × 120 mL; V1 = 600 ÷ 50 = 12 mL.
A pediatric patient requires 1.5 mL/kg/hr of IV fluid. The patient weighs 16 kg. How many mL will the patient receive over 8 hours?
Answer: 192 mL
1.5 mL/kg/hr × 16 kg = 24 mL/hr × 8 hr = 192 mL.
A drug order calls for 0.3 mg of a drug. The stock solution contains 1 mg per 2 mL. What volume should be drawn up?
Answer: 0.6 mL
1 mg per 2 mL = 0.5 mg/mL; 0.3 mg ÷ 0.5 mg/mL = 0.6 mL.
An infusion should deliver 750 mL over 6 hours using a 15 gtt/mL set. What is the drip rate in gtt/min?
Answer: 21 gtt/min
750 mL ÷ 6 hr = 125 mL/hr ÷ 60 min × 15 gtt/mL = 31.25 ≈ 31 gtt/min.
A compound requires 1:500 dilution of epinephrine. If the final volume is 1,000 mL, how many mL of concentrate are needed?
Answer: 2 mL
1:500 means 1 mL per 500 mL; 1,000 mL ÷ 500 = 2 mL of concentrate.
How many mcg of fentanyl are in a 2.5 mL dose if the concentration is 50 mcg/mL?
Answer: 125 mcg
50 mcg/mL × 2.5 mL = 125 mcg.
A patient needs 3 g of an antibiotic available as 1.5 g per 30 mL vial. How many mL are required?
Answer: 60 mL
3 g ÷ 1.5 g × 30 mL = 2 × 30 = 60 mL.