Common Registration Assessment, Part 1

Pizotifen 0.5mg and 1.5mg tablets and daily dose maximums for the GPhC assessment

Three original practice questions, with the working shown. Read the stated prescription or plan before calculating.

Published 7 November 2026. Independent revision material, not GPhC questions, not for patient care.

A man with a headache pressing his fingers to his temple
Photo from Pexels, used under the Pexels licence. It is a stock image and does not show the exercise.

The manufacturer's UK product information for pizotifen 0.5 mg tablets states that adults usually take 1.5 mg daily, either as a single dose at night or in three divided doses, adjusted to individual requirements up to a maximum of 4.5 mg daily.

The same information states that up to 3 mg may be given as a single dose, and that children from 2 years of age may take up to 1.5 mg daily, usually as a divided dose, although up to 1 mg has been given as a single dose at night.

Each stated maximum is a total daily amount; a divided regimen splits that total across the day, and the tablet strength supplied decides the count.

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

  1. Identify the stated daily dose in milligrams and the tablet strength supplied.
  2. Divide the daily dose by the tablet strength to count tablets per day.
  3. For a divided regimen, split the daily count evenly across the stated doses.
  4. 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 adult takes pizotifen 1.5 mg daily in three divided doses using 0.5 mg tablets. How many tablets are needed for 28 days?

Show the answer

Answer: 84 tablets

Working: 1.5 mg / 0.5 mg per tablet = 3 tablets each day, one per divided dose. 3 tablets x 28 days = 84 tablets.

Question 2

A fictional adult takes the stated maximum of 4.5 mg daily using 1.5 mg tablets. How many tablets is this each day?

Show the answer

Answer: 3 tablets

Working: 4.5 mg / 1.5 mg per tablet = 3 tablets each day.

Question 3

A fictional adult takes the largest stated single night dose of 3 mg using 0.5 mg tablets. How many tablets is that one dose?

Show the answer

Answer: 6 tablets

Working: 3 mg / 0.5 mg per tablet = 6 tablets in the single dose.

eMC SmPC: Pizotifen 0.5mg Tablets

https://www.medicines.org.uk/emc/product/13264/smpc

Where marks are lost

  • Treating the 4.5 mg daily maximum as a single-dose maximum when only up to 3 mg may be given as a single dose.
  • Counting one tablet per day instead of one tablet per divided dose in a three times daily regimen.
  • Mixing the 0.5 mg and 1.5 mg tablet strengths within one count.

Frequently asked questions

Are these official assessment questions?

No. They are original revision exercises, not official GPhC questions and not for patient care.

Does this calculation decide a real pizotifen dose?

No. Follow the stated prescription in the exercise. Real dosing is adjusted to individual requirements within the stated daily maximum, with lower limits for children.

How should I check the answer?

Check the requested unit, then confirm the tablet strength before turning a daily dose into a count.

Sources

The questions above are original and use fictional patients and prescriptions. PreRegExamPrep is not affiliated with or endorsed by the General Pharmaceutical Council.

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More calculation topics

See also the formula sheet, the eight sample questions and the approved calculator page.