APC Pharmaceutical Calculations 2 — Questions and Answers
Question 1: An IV infusion of 1000 mL must be administered evenly over 8 hours. What is the required flow rate in mL/hour?
- 100 mL/hr
- 125 mL/hr (Correct answer)
- 150 mL/hr
- 200 mL/hr
Correct answer: 125 mL/hr
Flow rate = 1000 mL ÷ 8 hours = 125 mL/hour.
Question 2: A child weighing 20 kg needs 10 mg/kg of ibuprofen. The available suspension contains 100 mg/5 mL. What volume is required per dose?
- 5 mL
- 10 mL (Correct answer)
- 15 mL
- 20 mL
Correct answer: 10 mL
Required dose: 20 kg × 10 mg/kg = 200 mg; volume: (200 ÷ 100) × 5 = 10 mL.
Question 3: An IV infusion set delivers 20 drops/mL. The prescribed rate is 150 mL/hour. What is the required drip rate in drops per minute?
- 25 drops/min
- 50 drops/min (Correct answer)
- 75 drops/min
- 100 drops/min
Correct answer: 50 drops/min
Drip rate = (150 mL/hr × 20 drops/mL) ÷ 60 min = 50 drops/min.
Question 4: A dobutamine infusion is prescribed at 2 mcg/kg/min for a 70 kg patient. What is the total infusion rate in mcg/min?
- 70 mcg/min
- 140 mcg/min (Correct answer)
- 210 mcg/min
- 280 mcg/min
Correct answer: 140 mcg/min
Rate = 2 mcg/kg/min × 70 kg = 140 mcg/min.
Question 5: A pharmacist prepares 50 g of a 1% w/w ointment. How many grams of active drug are needed?
- 0.5 g (Correct answer)
- 1 g
- 5 g
- 10 g
Correct answer: 0.5 g
1% w/w of 50 g = 0.01 × 50 = 0.5 g of active drug.
Question 6: A patient receives 15 mg of a drug three times daily. The maximum recommended daily dose is 60 mg/day. What percentage of the maximum dose is the patient receiving?
- 50%
- 60%
- 75% (Correct answer)
- 80%
Correct answer: 75%
Daily dose = 15 mg × 3 = 45 mg; percentage = (45 ÷ 60) × 100 = 75%.
Question 7: An antibiotic vial contains 500 mg of powder. After reconstitution with water, the final volume is 10 mL. What is the final concentration in mg/mL?
- 50 mg/mL (Correct answer)
- 100 mg/mL
- 25 mg/mL
- 200 mg/mL
Correct answer: 50 mg/mL
Concentration = 500 mg ÷ 10 mL = 50 mg/mL.
APC Pharmaceutical Calculations 2
An IV infusion of 1000 mL must be administered evenly over 8 hours.
What is the required flow rate in mL/hour?