Common Registration Assessment, Part 1
Betahistine tablet strengths and three daily doses for the GPhC assessment
Three original practice questions, with the working shown. Read the stated prescription or plan before calculating.
Published 4 November 2026. Independent revision material, not GPhC questions, not for patient care.
The manufacturer's UK product information for Serc-8 tablets states that adults initially take two tablets three times daily, preferably with meals.
The same information states that maintenance doses are generally in the range of 24 to 48 mg daily.
The NHS advises leaving six to eight hours between each betahistine dose.
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 a supply period. All prescriptions and patients here are fictional; these are revision materials, not for patient care.
The method
- Identify the stated dose per occasion and the number of doses per day.
- Multiply the dose by the number of daily doses for the daily total in milligrams.
- Divide the daily total by the tablet strength, or multiply the daily tablet count by the stated days for a supply.
- Keep milligrams and tablets separate; convert only when the question asks.
Three practice questions
Work each one on paper first, then open the answer. All patients and prescriptions are fictional.
Question 1
A fictional patient starts betahistine as two 8 mg tablets three times daily. How many milligrams is the total daily dose?
Show the answer
Answer: 48 mg
Working: 2 tablets x 8 mg = 16 mg per dose. 16 mg x 3 doses = 48 mg each day.
Question 2
A fictional patient's maintenance dose is betahistine 24 mg daily, taken as three divided doses using 8 mg tablets. How many tablets are taken each day?
Show the answer
Answer: 3 tablets
Working: 24 mg / 3 doses = 8 mg per dose. 8 mg / 8 mg per tablet = 1 tablet per dose, so 3 tablets each day.
Question 3
A fictional prescription reads betahistine 48 mg daily using 16 mg tablets, taken in three divided doses, for 28 days. How many tablets should be supplied?
Show the answer
Answer: 84 tablets
Working: 48 mg / 16 mg per tablet = 3 tablets each day. 3 tablets x 28 days = 84 tablets.
eMC SmPC: Serc-8 mg tablets
https://www.medicines.org.uk/emc/product/1171/smpc
Where marks are lost
- Reporting the amount per dose as the daily total when the schedule is three times daily.
- Mixing up 8 mg and 16 mg tablet strengths.
- Changing the arithmetic because doses are spaced six to eight hours apart.
Frequently asked questions
Are these official assessment questions?
No. They are original revision exercises, not official GPhC questions and not for patient care.
Does the six-to-eight-hour spacing change the tablet count?
No. It describes timing. Count the stated dose on each of the three daily occasions.
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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