Common Registration Assessment, Part 1

Rotigotine patch strengths and weekly titration steps for the GPhC assessment

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

Published 7 November 2026. Independent revision material, not GPhC questions, not for patient care.

A healthcare worker applying a white adhesive patch to a person's arm
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 rotigotine transdermal patches, for the symptomatic treatment of moderate to severe idiopathic Restless Legs Syndrome in adults, states that a single daily dose should be initiated at 1 mg/24 hours and may be increased in weekly increments of 1 mg/24 hours up to a maximum dose of 3 mg/24 hours.

The same information states that the need for continued treatment should be reconsidered every 6 months, that one patch is applied once a day at approximately the same time and remains on the skin for 24 hours before being replaced at a different site, and that the same application site should not be reused within 14 days.

It also states that treatment should be discontinued gradually, reducing the daily dose in steps of 1 mg/24 hours preferably every other day until complete withdrawal.

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 a supply period. All prescriptions and patients here are fictional; these are revision materials, not for patient care.

The method

  1. Identify the stated patch strength in mg per 24 hours and how often the dose changes.
  2. Count one patch for each 24 hour period at the stated strength.
  3. Multiply the daily patch count by the stated number of days for a supply quantity.
  4. Keep mg per 24 hours, patches and days 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 starts rotigotine 1 mg/24 hours, increased in weekly increments of 1 mg/24 hours up to 3 mg/24 hours. In which week of treatment is the 3 mg/24 hours dose first reached?

Show the answer

Answer: Week 3

Working: Week 1 at 1 mg/24 hours, week 2 at 2 mg/24 hours, week 3 at 3 mg/24 hours. The maximum is first reached in week 3.

Question 2

A fictional patient uses one rotigotine patch every 24 hours. How many patches are needed for a 28 day supply?

Show the answer

Answer: 28 patches

Working: One patch each day x 28 days = 28 patches.

Question 3

A fictional patient stops rotigotine from 3 mg/24 hours, reducing in steps of 1 mg/24 hours every other day. Each step lasts 2 days. How many days does the withdrawal take?

Show the answer

Answer: 6 days

Working: Three steps: 3 to 2 mg/24 hours, 2 to 1 mg/24 hours, then 1 to 0. 3 steps x 2 days = 6 days.

eMC SmPC: Rotigotine Luye 1 mg/24 hours Transdermal patch

https://www.medicines.org.uk/emc/product/100676/smpc

Where marks are lost

  • Counting the starting week as week 0, so the maximum appears to be reached a week earlier than it is.
  • Treating mg per 24 hours as a count of patches when only one patch is worn at a time.
  • Counting the withdrawal as daily reductions when the stated steps reduce the dose every other day.

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 rotigotine dose?

No. Follow the stated plan in the exercise. Real dosing for restless legs syndrome is titrated weekly, reviewed every 6 months and uses a different application site each day.

How should I check the answer?

Check the requested unit, then work backwards from the total to the stated patch strength and number of 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.