Common Registration Assessment, Part 1

Nifedipine modified-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 1 November 2026. Independent revision material, not GPhC questions, not for patient care.

Person using a digital blood pressure monitor on their arm
Photo from Pexels, used under the Pexels licence. It is a stock image and does not show the exercise.

The NHS describes nifedipine as a medicine used to treat high blood pressure and angina.

The manufacturer's UK product information for Adalat LA lists a usual starting dose of 20 mg or 30 mg once a day, with a maximum of 90 mg once a day.

Adalat LA is a modified-release tablet, so each tablet releases nifedipine slowly across the day and the dose is counted once a day.

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; only compare a daily dose against the stated maximum 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 takes nifedipine modified-release 30 mg once a day. How many tablets and how many milligrams is a 28-day supply?

Show the answer

Answer: 28 tablets; 840 mg

Working: 1 tablet x 28 days = 28 tablets; 30 mg x 28 days = 840 mg.

Question 2

A fictional patient takes 30 mg once a day for 2 weeks, then 60 mg once a day for the next 2 weeks. How many milligrams is the full 4 weeks?

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Answer: 1,260 mg

Working: (30 mg x 14 days) + (60 mg x 14 days) = 420 mg + 840 mg = 1,260 mg.

Question 3

A fictional prescription reads nifedipine modified-release 60 mg once a day using 30 mg tablets. How many tablets are taken each day, and is this within the stated 90 mg daily maximum?

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Answer: 2 tablets a day; yes, 60 mg is within the 90 mg maximum

Working: 60 mg / 30 mg = 2 tablets; 60 mg is less than the stated 90 mg daily maximum.

NHS: Nifedipine

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

Where marks are lost

  • Counting a once daily modified-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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