CETP Pharmaceutical Calculations 2 — Questions and Answers
Question 1: A 72-year-old male weighs 80 kg and has a serum creatinine of 1.0 mg/dL. Using the Cockcroft-Gault equation [CrCl = (140 − age) × weight ÷ (72 × SCr)], what is his estimated creatinine clearance?
- 55 mL/min
- 65 mL/min
- 75 mL/min (Correct answer)
- 85 mL/min
Correct answer: 75 mL/min
(140 − 72) × 80 ÷ (72 × 1.0) = 68 × 80 ÷ 72 ≈ 75.6 mL/min.
Question 2: How many milliequivalents (mEq) of potassium chloride are contained in 30 mL of a 2 mEq/mL solution?
- 15 mEq
- 30 mEq
- 60 mEq (Correct answer)
- 120 mEq
Correct answer: 60 mEq
2 mEq/mL × 30 mL = 60 mEq of potassium chloride.
Question 3: Using the alligation method, what volumes of 70% alcohol and 30% alcohol are needed to prepare 500 mL of 50% alcohol?
- 200 mL of 70% and 300 mL of 30%
- 250 mL of 70% and 250 mL of 30% (Correct answer)
- 300 mL of 70% and 200 mL of 30%
- 350 mL of 70% and 150 mL of 30%
Correct answer: 250 mL of 70% and 250 mL of 30%
Parts of 70% = 50 − 30 = 20; parts of 30% = 70 − 50 = 20; equal ratio = 250 mL each.
Question 4: A pediatric patient has a body surface area (BSA) of 0.5 m². The adult dose of a medication is 200 mg. Using the BSA method (Pediatric dose = [Child BSA ÷ 1.73 m²] × Adult dose), what is the appropriate pediatric dose?
- 29 mg
- 58 mg (Correct answer)
- 100 mg
- 115 mg
Correct answer: 58 mg
(0.5 ÷ 1.73) × 200 mg = 0.289 × 200 ≈ 58 mg.
Question 5: An IV infusion is ordered at 30 drops/min using a 20 drops/mL administration set. What is the equivalent infusion rate in mL/hr?
- 45 mL/hr
- 60 mL/hr
- 90 mL/hr (Correct answer)
- 120 mL/hr
Correct answer: 90 mL/hr
30 drops/min ÷ 20 drops/mL = 1.5 mL/min × 60 min/hr = 90 mL/hr.
Question 6: A powder for reconstitution has a powder volume of 1.5 mL. The final volume after reconstitution should be 5 mL. How much diluent must be added?
- 2.5 mL
- 3.5 mL (Correct answer)
- 5.0 mL
- 6.5 mL
Correct answer: 3.5 mL
Diluent volume = final volume − powder volume = 5.0 − 1.5 = 3.5 mL.
Question 7: A patient is prescribed atenolol 50 mg once daily for 30 days. What quantity of 50 mg tablets should be dispensed?
- 15 tablets
- 30 tablets (Correct answer)
- 60 tablets
- 90 tablets
Correct answer: 30 tablets
1 tablet/dose × 1 dose/day × 30 days = 30 tablets.
CETP Pharmaceutical Calculations 2
A 72-year-old male weighs 80 kg and has a serum creatinine of 1.0 mg/dL.
Using the Cockcroft-Gault equation [CrCl = (140 − age) × weight ÷ (72 × SCr)], what is his estimated creatinine clearance?