Common Registration Assessment, Part 1
Naproxen tablet strengths and daily maximums for the GPhC assessment
Three original practice questions, with the working shown. Read the stated prescription or plan before calculating.
Published 17 October 2026. Independent revision material, not GPhC questions, not for patient care.
The NHS lists naproxen tablets in 250 mg, 375 mg and 500 mg strengths, and a liquid containing either 25 mg or 50 mg in 1 mL.
Usual adult doses: 500 mg to 1,000 mg a day in 1 or 2 doses for joint conditions; 500 mg at first then 250 mg every 6 to 8 hours as needed for muscle and bone disorders and painful periods; 750 mg then 250 mg every 8 hours for gout. After the first day of painful periods, no more than 1,250 mg (five 250 mg tablets) in 24 hours.
Each question fixes the values needed for its arithmetic. Write the unit beside every step and check every total against a stated maximum. All prescriptions and patients here are fictional; these are revision materials, not for patient care.
The method
- Identify the exact strength, dose, frequency and maximum supplied in the question.
- Calculate one dose first, dividing prescribed mg by mg per tablet.
- Scale to a daily total using the stated frequency.
- Compare any daily total with the stated maximum before reporting it.
- Convert a liquid strength to mg/mL only if the question uses the liquid.
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 naproxen 1,000 mg a day in 2 doses using 500 mg tablets. How many tablets is each dose and each day?
Show the answer
Answer: 1 tablet per dose, 2 tablets a day
Working: 1,000 ÷ 2 = 500 mg per dose, which is one 500 mg tablet. 2 doses a day = 2 tablets a day.
Question 2
A fictional prescription specifies an initial naproxen dose of 750 mg for gout using 250 mg tablets. How many tablets is that one dose?
Show the answer
Answer: 3 tablets
Working: 750 ÷ 250 = 3 tablets.
Question 3
A fictional plan for painful periods specifies, after the first day, no more than 1,250 mg in 24 hours using 250 mg tablets. What is the maximum number of tablets in 24 hours, and how many full days does a pack of 30 tablets last at that maximum?
Show the answer
Answer: 5 tablets in 24 hours, 6 days
Working: 1,250 ÷ 250 = 5 tablets. 30 ÷ 5 = 6 days.
Exam approach
Per-dose and per-day are different checks. The stated maximum caps the daily total even when each single dose looks small.
Where marks are lost
- Exceeding a stated 24 hour maximum by counting only per dose.
- Mixing the two liquid strengths, which differ by a factor of two.
- 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.
Why is the 24 hour maximum a calculation check?
A schedule can stay within per-dose limits yet pass a daily maximum, so always compare the total.
How should I check the answer?
Check the requested unit, then work backwards from the quantity to the stated dose and duration.
Sources
- NHS: How and when to take naproxen
- GPhC, Common Registration Assessment specification and permitted items for 2026
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
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See also the formula sheet, the eight sample questions and the approved calculator page.