Common Registration Assessment, Part 1

Entacapone tablets with each levodopa dose for the GPhC assessment

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

Published 13 November 2026. Independent revision material, not GPhC questions, not for patient care.

Hands holding an assortment of tablets and capsules
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 entacapone 200 mg film-coated tablets states that one 200 mg tablet is taken with each levodopa and dopa decarboxylase inhibitor dose.

The same information gives a maximum recommended dose of 200 mg ten times daily, that is 2,000 mg of entacapone per day.

Because each tablet is tied to a levodopa dose, the daily entacapone total is set by the number of levodopa doses, not by a fixed schedule of its own.

Each question fixes the values needed for its arithmetic. Count the levodopa doses first, then convert to entacapone tablets and mg. All prescriptions and patients here are fictional; these are revision materials, not for patient care.

The method

  1. Count the stated number of levodopa doses per day.
  2. Take one 200 mg entacapone tablet per levodopa dose.
  3. Multiply the tablet count by 200 mg for the daily total.
  4. Check the count against the printed maximum of ten doses (2,000 mg) per day.

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 levodopa with a dopa decarboxylase inhibitor four times a day, with entacapone alongside. How many entacapone tablets, and how many mg of entacapone, is that each day?

Show the answer

Answer: 4 tablets; 800 mg daily

Working: One 200 mg tablet goes with each levodopa dose, so 4 doses give 4 tablets, and 4 x 200 = 800 mg.

Question 2

A fictional adult takes levodopa with a dopa decarboxylase inhibitor six times a day, with entacapone alongside. What is the daily entacapone dose in mg, and how many tablets does a 28-day supply need?

Show the answer

Answer: 1,200 mg daily; 168 tablets

Working: 6 doses give 6 x 200 = 1,200 mg daily. For 28 days, 6 x 28 = 168 tablets.

Question 3

A fictional adult's levodopa schedule rises to eleven doses a day. Can entacapone still be taken with every dose, and what does the printed maximum say?

Show the answer

Answer: No; the printed maximum is ten doses, 2,000 mg of entacapone per day

Working: Eleven tablets would be 11 x 200 = 2,200 mg, which exceeds the printed maximum of 2,000 mg (ten 200 mg tablets) per day, so entacapone cannot cover all eleven doses within the stated maximum.

eMC SmPC: Entacapone Viatris 200 mg film-coated tablets

https://www.medicines.org.uk/emc/product/8818/smpc

Where marks are lost

  • Taking entacapone at times when no levodopa dose is due.
  • Counting past the printed maximum of ten tablets (2,000 mg) a day.
  • Treating entacapone as a standalone Parkinson's treatment rather than an add-on to levodopa with a dopa decarboxylase inhibitor.

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 dose?

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

How should I check the answer?

Count the levodopa doses, take one 200 mg tablet per dose, multiply for the mg total, then check against the ten-dose (2,000 mg) daily maximum.

Sources

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

Practise until the method is automatic

Try 15 free questions with worked answers. No sign-up required.

Try 15 free questionsSee pricing

More calculation topics

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