Free NMC-CBT Drug Calculations and Numeracy Questions and Answers 1 — Questions and Answers
Question 1: A patient is prescribed 1 litre of Normal Saline to be infused over 8 hours. The giving set has a drop factor of 20 drops/mL. At what rate should the infusion be set in drops per minute (gtt/min)?
- 21 gtt/min
- 35 gtt/min
- 42 gtt/min (Correct answer)
- 50 gtt/min
Correct answer: 42 gtt/min
First, calculate the volume per hour (1000 mL / 8 hours = 125 mL/hr). Then, calculate the volume per minute (125 mL / 60 min ≈ 2.083 mL/min). Finally, multiply by the drop factor (2.083 mL/min * 20 gtt/mL ≈ 41.67 gtt/min), which rounds to 42 gtt/min.
Question 2: A patient is prescribed 120 mg of paracetamol suspension. The stock available is 250 mg in 5 mL. What volume in mL should you administer?
- 2.0 mL
- 2.4 mL (Correct answer)
- 4.8 mL
- 5.2 mL
Correct answer: 2.4 mL
The formula to use is (What you want / What you've got) x Volume it comes in. This translates to (120 mg / 250 mg) * 5 mL. This calculation equals 2.4 mL.
Question 3: An infusion pump must be set to deliver 500 mg of an antibiotic in 100 mL of fluid over 30 minutes. What rate should the pump be set to in mL/hour?
- 50 mL/hr
- 100 mL/hr
- 150 mL/hr
- 200 mL/hr (Correct answer)
Correct answer: 200 mL/hr
The pump needs to deliver 100 mL in 30 minutes. To find the hourly rate, you need to determine how much would be delivered in 60 minutes. Since 60 minutes is twice as long as 30 minutes, you multiply the volume by 2 (100 mL * 2 = 200 mL), so the rate is 200 mL/hour.
Question 4: A patient is prescribed 0.5 g of amoxicillin. The tablets available are 250 mg. How many tablets should be administered?
- 0.5 tablets
- 1 tablet
- 2 tablets (Correct answer)
- 4 tablets
Correct answer: 2 tablets
First, convert the prescribed dose to the same unit as the available stock. 0.5 grams is equal to 500 milligrams. Then, divide the prescribed dose by the stock strength (500 mg / 250 mg = 2).
Question 5: A patient weighing 72 kg is prescribed a drug at a dose of 5 mg per kg. What is the total dose required in mg?
- 14.4 mg
- 77 mg
- 360 mg (Correct answer)
- 720 mg
Correct answer: 360 mg
To calculate the total dose, multiply the patient's weight in kg by the prescribed dose per kg. The calculation is 72 kg * 5 mg/kg, which equals 360 mg. This ensures the patient receives a dose appropriate for their body weight.
Question 6: You need to administer 30 mg of a drug that is available as a 50 mg/2 mL solution. What volume in mL do you need to draw up?
- 0.6 mL
- 1.2 mL (Correct answer)
- 1.5 mL
- 3.3 mL
Correct answer: 1.2 mL
Using the formula (Dose required / Stock strength) x Stock volume, the calculation is (30 mg / 50 mg) x 2 mL. This simplifies to 0.6 x 2 mL, which equals 1.2 mL. This ensures the correct dose is administered from the available solution.
Free NMC-CBT Drug Calculations and Numeracy Questions and Answers 1
A patient is prescribed 1 litre of Normal Saline to be infused over 8 hours.
The giving set has a drop factor of 20 drops/mL.
At what rate should the infusion be set in drops per minute (gtt/min)?