Common Registration Assessment, Part 1

Linaclotide 290 microgram capsules and once-daily courses for the GPhC assessment

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

Published 11 November 2026. Independent revision material, not GPhC questions, not for patient care.

Fingers holding a single clear capsule
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 Constella 290 micrograms hard capsules states that the recommended dose is one capsule (290 micrograms) once daily, and that the capsule should be taken at least 30 minutes before a meal.

The same information states that physicians should periodically assess the need for continued treatment, that if patients have not improved after 4 weeks of treatment they should be re-examined and the benefit and risks of continuing reconsidered, and that efficacy was established in studies for up to 6 months.

With one fixed strength and a once-daily schedule, the arithmetic is capsule counts over stated days and microgram totals from the count.

Each question fixes the values needed for its arithmetic. Write the unit beside every step and distinguish capsules from micrograms. All prescriptions and patients here are fictional; these are revision materials, not for patient care.

The method

  1. Read the stated number of days or weeks at one capsule daily.
  2. Multiply days by one for the capsule count.
  3. Multiply the capsule count by 290 micrograms for a total in micrograms, only when asked.
  4. Keep capsules, micrograms, days and weeks 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 linaclotide at the label dose. How many capsules are taken in a 7-day week, and how many micrograms of linaclotide is that in total?

Show the answer

Answer: 7 capsules; 2030 micrograms

Working: One capsule once daily for 7 days = 7 capsules. 7 x 290 = 2030 micrograms.

Question 2

A fictional adult takes linaclotide once daily and is re-examined at the label's 4-week point for lack of improvement. How many capsules have been taken by that review?

Show the answer

Answer: 28 capsules

Working: 1 capsule x 28 days = 28 capsules over the 4 weeks.

Question 3

A fictional patient continues linaclotide once daily for 12 weeks, within the label's studied duration. How many capsules are needed, and what is the total in micrograms?

Show the answer

Answer: 84 capsules; 24,360 micrograms

Working: 12 weeks x 7 days = 84 days, one capsule daily: 84 capsules. 84 x 290 = 24,360 micrograms (24.36 mg), inside the up-to-6-months studied duration.

eMC SmPC: Constella 290 micrograms hard capsules

https://www.medicines.org.uk/emc/product/2041/smpc

Where marks are lost

  • Rounding micrograms into milligrams mid-question; keep totals in micrograms unless the question asks for mg.
  • Dropping the before-food timing; the label says the capsule is taken at least 30 minutes before a meal.
  • Assuming open-ended continuation; the label re-examines patients who have not improved after 4 weeks.

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 linaclotide course?

No. Follow the stated plan in the exercise. Real courses follow the prescriber and the product information.

How should I check the answer?

Count one capsule per day over the stated days or weeks, then multiply by 290 micrograms only when a total is asked.

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.