Common Registration Assessment, Part 1
Eplerenone 25mg and 50mg tablet doses for the GPhC assessment
Three original practice questions, with the working shown. Read the stated prescription or plan before calculating.
Published 27 October 2026. Independent revision material, not GPhC questions, not for patient care.
The NHS lists eplerenone as 25 mg and 50 mg tablets; the usual starting dose is 25 mg once a day.
The NHS notes the dose may be increased to 50 mg once a day, or adjusted after blood tests that check potassium levels.
Each question fixes the values needed for its arithmetic. Write the unit beside every step and distinguish a single dose from a daily total or course supply. All prescriptions and patients here are fictional; these are revision materials, not for patient care.
The method
- Identify the exact formulation, strength, dose and frequency supplied in the question.
- Convert an X mg/5 mL strength to mg/mL if a dose-to-volume conversion is needed.
- Calculate one dose first; for tablets or capsules divide prescribed mg by mg per unit.
- Scale to the stated frequency and duration only when a total quantity is requested.
- Apply whole-container or complete-day rounding only if the question specifies it.
Three practice questions
Work each one on paper first, then open the answer. All patients and prescriptions are fictional.
Question 1
A fictional prescription specifies eplerenone 25 mg once a day for 28 days, using 25 mg tablets. How many tablets cover the course?
Show the answer
Answer: 28 tablets
Working: 1 tablet × 28 days = 28 tablets.
Question 2
A fictional plan increases eplerenone to 50 mg once a day, using 25 mg tablets. How many tablets is one dose?
Show the answer
Answer: 2 tablets
Working: 50 ÷ 25 = 2 tablets.
Question 3
A fictional plan is eplerenone 50 mg once a day for 30 days, using 50 mg tablets. How many tablets cover the course?
Show the answer
Answer: 30 tablets
Working: 1 tablet × 30 days = 30 tablets.
NHS: How and when to take eplerenone
https://www.nhs.uk/medicines/eplerenone/how-and-when-to-take-eplerenone/
Where marks are lost
- Using a remembered strength or schedule instead of the stated product.
- Reporting a daily total when the question asks for one dose or the course.
- Treating arithmetic as evidence that a real prescription is clinically suitable.
Frequently asked questions
Are these official assessment questions?
No. They are original revision exercises, not official GPhC questions and not for patient care.
Can a quantity calculation justify a formulation switch?
No. Follow the formulation and prescription in the exercise. Real switches and dose changes need clinical checks.
How should I check the answer?
Check the requested unit, then work backwards from the quantity to the stated dose and duration.
Sources
The questions above are original and use fictional patients and prescriptions. PreRegExamPrep is not affiliated with or endorsed by the General Pharmaceutical Council.
Practise until the method is automatic
Try 15 free questions with worked answers. No sign-up required.
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