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Free nursing drug dosage calculation practice

Tablets, liquids, weight-based doses and infusion rates, with every step worked out.

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About this question pool

Drug dosage calculations has 4608 free practice questions that fit these exams: NCLEX-RN, NMC CBT, Gulf exams.

The questions are original. They were drafted with automated tools and checked by automated review steps. They are not official exam material and have not been reviewed one by one by a licensed nurse. How we make and check content

Exam guides: NCLEX-RN, NMC CBT and OSCE, Prometric, DHA and Gulf exams

Countries that use this practice: United Kingdom, United States, Australia, Canada, Ireland, New Zealand, Germany, Saudi Arabia, United Arab Emirates, Qatar, Kuwait, Oman

Three sample questions

1. The prescriber orders captopril 50 mg orally. Available: captopril 25 mg tablets. How many tablets will you give? Tablets are scored and may be halved; give the answer to the nearest half tablet.

  1. 2 tablets
  2. 0.5 tablets
  3. 20 tablets
  4. 2.5 tablets
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A. 2 tablets

Desired ÷ have = 50 mg ÷ 25 mg = 2 tablets. Inverting the ratio (have ÷ desired) or slipping a decimal place gives the wrong distractors. Practice calculation only: always follow your local protocol and prescriber's order.

2. Infuse 250 mL over 1 hour by gravity using a microdrip (paediatric) giving set with a drop factor of 60 drops/mL. How many drops per minute? Round to the nearest whole drop.

  1. 83 drops/min
  2. 250 drops/min
  3. 2,500 drops/min
  4. 252 drops/min
Show the answer

B. 250 drops/min

Drops/min = (volume × drop factor) ÷ time in minutes = (250 mL × 60 drops/mL) ÷ 60 min = 250 drops/min. Errors: leaving out the drop factor, dividing by hours instead of minutes, or using the wrong set's drop factor. Practice calculation only: always follow your local protocol and prescriber's order.

3. An infusion of 1,500 mL was due to run over 10 hours. At the 4-hour check, 360 mL has gone in. To complete it in the remaining time as prescribed, what rate in mL/h is required? Round to the nearest whole number.

  1. 150 mL/h
  2. 190 mL/h
  3. 114 mL/h
  4. 250 mL/h
Show the answer

B. 190 mL/h

Volume left = 1,500 − 360 = 1,140 mL. Time left = 10 − 4 = 6 h. New rate = 1,140 ÷ 6 = 190 mL/h. Keeping the original rate (150 mL/h) or dividing by the full time are the usual errors. Large catch-up rates need the prescriber's agreement and a fluid-overload check. In practice, check the result against the prescription and local protocol.

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