Common Registration Assessment, Part 1

Felodipine prolonged-release tablets and once daily doses for the GPhC assessment

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

Published 2 November 2026. Independent revision material, not GPhC questions, not for patient care.

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The NHS describes felodipine as a medicine used to treat high blood pressure and angina, taken once a day in the morning.

The manufacturer's UK product information for felodipine prolonged-release tablets lists 2.5 mg, 5 mg and 10 mg strengths, with a recommended starting dose of 5 mg once a day and a usual maintenance of 5 mg to 10 mg once a day.

The same product information notes a 2.5 mg start can be considered in older patients, and that the tablets are swallowed whole in the morning without food or with a light meal.

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

  1. Identify the exact strength and frequency stated in the question.
  2. Count one tablet per day for each tablet taken once a day before scaling to the stated period.
  3. Calculate one day first, then scale to the stated number of days or weeks.
  4. Convert weeks into days by multiplying by 7 before counting doses.
  5. Keep milligrams and tablets separate; convert only if 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 takes felodipine prolonged-release 5 mg once a day. How many tablets and how many milligrams is a 28-day supply?

Show the answer

Answer: 28 tablets; 140 mg

Working: 1 tablet x 28 days = 28 tablets; 5 mg x 28 days = 140 mg.

Question 2

A fictional patient takes 5 mg once a day for 2 weeks, then 10 mg once a day for the next 2 weeks. How many milligrams is the full 4 weeks?

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Answer: 210 mg

Working: (5 mg x 14 days) + (10 mg x 14 days) = 70 mg + 140 mg = 210 mg.

Question 3

A fictional prescription reads felodipine prolonged-release 10 mg once a day using 5 mg tablets. How many tablets should be supplied for 28 days?

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Answer: 56 tablets

Working: 10 mg / 5 mg = 2 tablets a day; 2 tablets x 28 days = 56 tablets.

NHS: Felodipine

https://www.nhs.uk/medicines/felodipine/

Where marks are lost

  • Counting a once daily prolonged-release tablet more than once in a day.
  • Reporting milligrams when the question asks for a tablet count.
  • 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 dose-total calculation justify changing a real dose?

No. Follow the steps in the exercise. Real dose changes are gradual and 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.

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More calculation topics

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