Many medical students and Pharmascholar clients tell me the same thing:
"I know the clinical knowledge, but I struggle when calculations, prescribing decisions and exam pressure are combined."
The Prescribing Safety Assessment (PSA) is designed to test practical prescribing skills, not just your ability to recall facts. The good news is that regular practice can significantly improve your confidence and performance. Below are five PSA-style questions covering calculations, prescribing and prescription review skills.
Try each question before revealing the answer.....
Question 1: Paediatric IV Infusion Calculation
A 2-year-old boy is admitted to the paediatric emergency department with status epilepticus. He weighs 11 kg and requires a loading dose of phenytoin 20 mg/kg IV. The required dose has been diluted to a total volume of 50 mL. The maximum rate of infusion is 1 mg/kg/minute. What is the maximum rate at which the infusion should be administered?
A. 1.0 mL/min
B. 2.0 mL/min
C. 2.5 mL/min
D. 5.0 mL/min
E. 10 mL/min
**Working
Loading dose:
20 mg/kg × 11 kg = 220 mg
Maximum administration rate:
1 mg/kg/min × 11 kg = 11 mg/min
220 mg is contained within 50 mL.
11 mg therefore corresponds to:
(11 ÷ 220) × 50
= 2.5 mL/min
Question 2: Dose Calculation
A 45-year-old man weighing 57 kg presents with persistent vomiting. Metoclopramide injection is available as 5 mg/mL. The maximum dose is 500 micrograms/kg/day, given in three divided doses. What volume should be administered every 8 hours?
A. 0.95 mL
B. 1.5 mL
C. 1.9 mL
D. 2.4 mL
E. 3.0 mL
**Working
Maximum daily dose:
500 micrograms × 57 kg
= 28,500 micrograms
= 28.5 mg/day
Three divided doses:
28.5 ÷ 3 = 9.5 mg
Volume required:
9.5 mg ÷ 5 mg/mL
= 1.9 mL
Question 3: Infusion Rate Interpretation
A 60 kg patient is receiving: Dobutamine 200 mg in 50 mL. The infusion runs at 4.5 mL/hour. What dose is being administered?
A. 2 micrograms/kg/min
B. 3 micrograms/kg/min
C. 4 micrograms/kg/min
D. 5 micrograms/kg/min
E. 6 micrograms/kg/min
**Working
Concentration:
200 mg ÷ 50 mL
= 4 mg/mL
Dose delivered:
4.5 × 4
= 18 mg/hour
18 mg/hour
= 18,000 micrograms/hour
18,000 ÷ 60
= 300 micrograms/minute
300 ÷ 60 kg
= 5 micrograms/kg/min
Question 4: Emergency Prescribing
A 22-year-old woman develops:
Tongue swelling
Widespread rash
Wheeze
Hypotension
One hour after taking amoxicillin. Which drug should be prescribed immediately?
A. Chlorphenamine
B. Hydrocortisone
C. Salbutamol
D. Adrenaline IM
E. Cetirizine
**Working
This is a classic presentation of anaphylaxis with airway involvement and cardiovascular compromise. Intramuscular adrenaline is the first-line emergency treatment.
Answer
✅ Adrenaline 500 micrograms IM once only
Question 5: Prescription Review
An elderly man develops acute urinary retention. Review his medicines and identify the THREE most likely contributors. Which option is correct?
A. Ramipril, atorvastatin, omeprazole
B. Amitriptyline, oxybutynin, hyoscine butylbromide
C. Metformin, amlodipine, aspirin
D. Furosemide, bisoprolol, ramipril
E. Simvastatin, folic acid, lansoprazole
**Working
All three medicines possess significant anticholinergic activity, reducing bladder contraction and increasing the risk of urinary retention, particularly in older patients.
Answer
✅ B. Amitriptyline, oxybutynin and hyoscine butylbromide
Want 10 More PSA Questions?
If you found these questions useful, I've created an additional 10 PSA-style questions with full answers and worked explanations, covering:
✅ Calculations
✅ Prescribing Skills
✅ Prescription Review
✅ Planning & Management
To receive your FREE PSA Question Pack, simply complete the Contact Us form and I'll personally email the resource directly to you.
I also offer a free 20-minute consultation for students preparing for the PSA, OSPAP assessments and prescribing examinations. Don't leave easy marks behind. Practise regularly, build confidence and approach your PSA with a clear strategy.
PSA Tutor UK
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