NMC CBT Drug Calculations and Numeracy 2

Question 1

A patient is prescribed 1.2 g of amoxicillin orally. The pharmacy supplies 500 mg capsules. How many capsules should be administered?

Accepted Answer

2.4 capsules — query the prescription

Answer

1.2 g = 1200 mg. 1200/500 = 2.4. Capsules cannot be divided, so query the prescription with the prescriber.

Question 2

An IV infusion of 1 litre of 0.9% NaCl is prescribed over 8 hours. The giving set delivers 20 drops per mL. What is the drip rate?

Accepted Answer

42 drops/min

Answer

Drip rate = (1000 x 20) / (8 x 60) = 20000/480 = 41.67, rounded to 42 drops/min.

Question 3

A child weighing 22 kg is prescribed paracetamol at 15 mg/kg. The oral suspension contains 250 mg in 5 mL. What volume should be administered?

Accepted Answer

6.6 mL

Answer

Dose = 15 x 22 = 330 mg. Volume = (330/250) x 5 = 6.6 mL.

Question 4

A 70 kg patient requires dopamine at 5 mcg/kg/min. The bag contains 400 mg in 250 mL. What is the infusion rate in mL/hr?

Accepted Answer

13.1 mL/hr

Answer

Dose/min = 5 x 70 = 350 mcg. Dose/hr = 350 x 60 = 21000 mcg = 21 mg. Concentration = 400/250 = 1.6 mg/mL. Rate = 21/1.6 = 13.1 mL/hr.

Question 5

A prescription states: 'morphine 10 mg in 10 mL 0.9% NaCl IV, give 3 mg.' How many mL should be drawn up?

Accepted Answer

3 mL

Answer

Concentration = 10 mg/10 mL = 1 mg/mL. Volume = 3/1 = 3 mL.

(NMC CBT) Nursing and Midwifery Council Computer-Based Test Practice Test