Common Registration Assessment, Part 1

Quinine sulfate tablet doses for night cramps for the GPhC assessment

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

Published 12 November 2026. Independent revision material, not GPhC questions, not for patient care.

A lit silver bedside lamp in a dark bedroom
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 Quinine Sulfate 200 mg tablets states that for nocturnal leg cramps the recommended dose is 200 mg at bedtime, with a maximum of 300 mg.

The same information states that benefit may take up to 4 weeks to appear, that treatment should stop after a 4-week trial if there is no benefit, and that treatment should be interrupted about every 3 months to review the need.

For falciparum malaria, the product information states 600 mg every 8 hours for 7 days in adults and children aged 12 years and over.

Each question fixes the values needed for its arithmetic. Keep the bedtime cramps dose separate from the eight-hourly malaria schedule. All prescriptions and patients here are fictional; these are revision materials, not for patient care.

The method

  1. Identify whether the question is about cramps or malaria.
  2. Convert the stated milligrams into 200 mg tablets.
  3. Treat every 8 hours as 3 doses a day.
  4. Multiply the daily tablet count by the stated days for a course total.
  5. Count a 4-week trial as 28 nights.

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 quinine sulfate 200 mg at bedtime for night cramps. Using 200 mg tablets, how many tablets does the 4-week trial use?

Show the answer

Answer: 28 tablets

Working: 1 tablet each night; 4 weeks = 28 nights; 28 x 1 = 28 tablets.

Question 2

A fictional adult takes quinine sulfate 600 mg every 8 hours for 7 days for malaria. Using 200 mg tablets, how many tablets is the full course?

Show the answer

Answer: 63 tablets

Working: 600 mg / 200 mg = 3 tablets per dose; every 8 hours = 3 doses a day, so 9 tablets a day; 9 x 7 days = 63 tablets.

Question 3

A fictional adult is prescribed the maximum cramps dose of 300 mg at bedtime. Using 200 mg tablets, how many tablets is each dose?

Show the answer

Answer: One and a half tablets

Working: 300 mg / 200 mg = 1.5, so each bedtime dose is one and a half of the 200 mg tablets.

eMC SmPC: Quinine Sulfate 200mg Film-coated Tablets

https://www.medicines.org.uk/emc/product/101900/smpc

Where marks are lost

  • Counting every 8 hours as 2 doses a day instead of 3.
  • Carrying the 600 mg malaria dose into a cramps question, or the 200 mg bedtime dose into malaria.
  • Counting a 4-week trial as 30 days instead of 28.

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 quinine course?

No. Follow the stated prescription in the exercise. Real treatment follows the prescriber and the product information for the named tablet.

How should I check the answer?

Name the indication, divide the stated milligrams by 200 mg for tablets per dose, count every 8 hours as 3 doses a day, then multiply by the stated days.

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.