Free Drug Calculations and Dosage MCQs with Answers
50 Drug Calculations and Dosage MCQs from Nursing Pharmacology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Drug calculations apply measurement systems, unit conversions, dosage formulas, tablet and liquid doses, percentage and ratio strength, and weight based dosing. Work also includes calculating IV flow rates, infusion times and doses for children, while distinguishing the prescribed dose from the available concentration.
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50 questions · page 2 of 3
- A. 1 mL
- B. 2 mL
- C. 4 mL
- D. 5 mL
Explanation: First convert weight: 44 lb ÷ 2.2 = 20 kg. The required dose is 20 × 5 = 100 mg, and 100 mg ÷ 50 mg/mL = 2 mL.
Correct answer: 2 mL- A. 0.5 tablet
- B. 1 tablet
- C. 1.5 tablets
- D. 2 tablets
Explanation: Use the formula prescribed dose ÷ available dose: 750 mg ÷ 500 mg = 1.5 tablets.
Correct answer: 1.5 tablets- A. 30 drops/minute
- B. 40 drops/minute
- C. 50 drops/minute
- D. 60 drops/minute
Explanation: Apply the formula: 1,200 mL × 20 drops/mL ÷ 600 minutes = 40 drops/minute. The 10-hour infusion must first be converted to 600 minutes.
Correct answer: 40 drops/minute- A. 8 hours
- B. 10 hours
- C. 12 hours
- D. 15 hours
Explanation: Time equals total volume ÷ hourly rate: 1,500 mL ÷ 125 mL/hour = 12 hours. This calculation assumes the prescribed rate remains constant.
Correct answer: 12 hours- A. 5 mL
- B. 8 mL
- C. 10 mL
- D. 12 mL
Explanation: The daily dose is 18 × 30 = 540 mg, so each of three doses is 180 mg. Since 90 mg is in 5 mL, 180 mg requires 10 mL.
Correct answer: 10 mL- A. 0.45 g
- B. 4.5 g
- C. 9 g
- D. 45 g
Explanation: A 0.9% w/v solution contains 0.9 g in each 100 mL. For 500 mL, 0.9 × 5 = 4.5 g.
Correct answer: 4.5 g- A. 0.25 mL
- B. 0.5 mL
- C. 1 mL
- D. 2 mL
Explanation: Volume equals prescribed dose ÷ concentration: 75 micrograms ÷ 150 micrograms/mL = 0.5 mL.
Correct answer: 0.5 mL- A. 10 mL
- B. 12 mL
- C. 15 mL
- D. 20 mL
Explanation: Use 375 mg × 10 mL ÷ 250 mg = 15 mL. The available concentration is used rather than treating the prescribed milligram dose as a volume.
Correct answer: 15 mL- A. 150 mL/hour
- B. 180 mL/hour
- C. 200 mL/hour
- D. 225 mL/hour
Explanation: The pump rate is total volume ÷ time: 900 mL ÷ 5 hours = 180 mL/hour. This uses an electronic pump, so a drop factor is not needed.
Correct answer: 180 mL/hour- A. 0.65 mL
- B. 1.0 mL
- C. 1.3 mL
- D. 2.6 mL
Explanation: The concentration is 2,000 units ÷ 4 mL = 500 units/mL. The required volume is 650 units ÷ 500 units/mL = 1.3 mL.
Correct answer: 1.3 mL- A. 2.8 mL
- B. 3.0 mL
- C. 3.5 mL
- D. 4.0 mL
Explanation: First calculate the concentration: 80 mg ÷ 2 mL = 40 mg/mL. Then calculate 140 mg ÷ 40 mg/mL = 3.5 mL.
Correct answer: 3.5 mL- A. 0.8 micrograms
- B. 8 micrograms
- C. 80 micrograms
- D. 800 micrograms
Explanation: One milligram equals 1,000 micrograms, so 0.08 mg × 1,000 = 80 micrograms.
Correct answer: 80 micrograms- A. 4.5 mL
- B. 6 mL
- C. 9 mL
- D. 18 mL
Explanation: The daily dose is 12 kg × 18 mg = 216 mg. Each of two doses is 108 mg, and the concentration is 60 mg ÷ 5 mL = 12 mg/mL.
Correct answer: 9 mL- A. 8 hours
- B. 10 hours
- C. 12 hours
- D. 14 hours
Explanation: Infusion time equals total volume ÷ hourly rate. The calculation is 1,440 mL ÷ 120 mL/hour = 12 hours.
Correct answer: 12 hours- A. 0.24 g
- B. 2.4 g
- C. 24 g
- D. 240 g
Explanation: A 3% w/v solution contains 3 g in every 100 mL. For 80 mL, the calculation is 3 g × 80 ÷ 100 = 2.4 g. The percentage is not 3 g per 1 mL.
Correct answer: 2.4 g- A. 12 mg
- B. 20 mg
- C. 24 mg
- D. 60 mg
Explanation: One gram equals 1,000 mg, so the concentration is 1,000 mg ÷ 500 mL = 2 mg/mL. In 12 mL, the amount is 12 × 2 = 24 mg.
Correct answer: 24 mg- A. 1.2 mL
- B. 1.5 mL
- C. 1.7 mL
- D. 2.0 mL
Explanation: The concentration after reconstitution is 750 mg ÷ 3 mL = 250 mg/mL. The required volume is 425 mg ÷ 250 mg/mL = 1.7 mL.
Correct answer: 1.7 mL- A. 0.72 mL
- B. 1.08 mL
- C. 1.44 mL
- D. 2.88 mL
Explanation: The prescribed dose is 72 kg × 0.08 mg/kg = 5.76 mg. At a concentration of 4 mg/mL, the volume is 5.76 mg ÷ 4 mg/mL = 1.44 mL.
Correct answer: 1.44 mL- A. Two tablets
- B. Three tablets
- C. Four tablets
- D. Five tablets
Explanation: First convert 1.2 g to 1,200 mg. Then divide 1,200 mg by 400 mg per tablet, giving 3 tablets.
Correct answer: Three tablets- A. 0.5 mL
- B. 1 mL
- C. 1.5 mL
- D. 2 mL
Explanation: Use the formula: volume = prescribed dose divided by available dose, multiplied by available volume. Thus, 2.5 mg ÷ 5 mg × 2 mL = 1 mL.
Correct answer: 1 mL