Common Registration Assessment, Part 1

Methyldopa 250 mg tablets and divided daily doses for the GPhC assessment

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

Published 12 November 2026. Independent revision material, not GPhC questions, not for patient care.

A clinician's open hand holding white tablets
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 Methyldopa 250 mg tablets states that the usual starting dose is 250 mg two or three times a day for the first two days.

The same information states that the dose is then adjusted at intervals of not less than two days, and that the maximum recommended daily dosage is 3 g.

The product information also states that in patients already on other antihypertensive treatment, methyldopa should be limited to an initial dose of not more than 500 mg daily.

Each question fixes the values needed for its arithmetic. Write the unit beside every step and distinguish a per-dose count from a daily total. All prescriptions and patients here are fictional; these are revision materials, not for patient care.

The method

  1. Identify whether the stated schedule is two or three times a day.
  2. Multiply the per-dose tablets by the daily frequency for the daily count.
  3. Divide a stated daily milligram figure by 250 mg for the tablet count.
  4. Respect the printed 3 g daily maximum before reporting any increased dose.
  5. Count review intervals as at least 2 days when scheduling increases.

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 methyldopa at 250 mg three times a day for two days. How many milligrams per day is that, and how many 250 mg tablets cover the two days?

Show the answer

Answer: 750 mg per day; 6 tablets

Working: 3 doses x 250 mg = 750 mg a day; 3 tablets a day x 2 days = 6 tablets.

Question 2

A fictional prescription reads methyldopa at the maximum recommended daily dosage of 3 g, in divided doses. Using 250 mg tablets, how many tablets per day is that?

Show the answer

Answer: 12 tablets per day

Working: 3 g = 3,000 mg; 3,000 mg / 250 mg = 12 tablets a day.

Question 3

A fictional adult already on other antihypertensives starts methyldopa at 500 mg daily. The daily dose is then increased by 250 mg at each review, with reviews no more often than every 2 days. What is the earliest day on which the daily dose can reach 1,500 mg?

Show the answer

Answer: Day 9

Working: 1,500 mg - 500 mg = 1,000 mg to add; 1,000 / 250 = 4 increases; at one increase every 2 days the earliest increases fall on days 3, 5, 7 and 9, so the dose first reaches 1,500 mg on day 9.

eMC SmPC: Methyldopa Tablets 250 mg

https://www.medicines.org.uk/emc/product/4667/smpc

Where marks are lost

  • Doubling a twice-daily schedule when the stated schedule is three times a day.
  • Exceeding the printed 3 g daily maximum when scaling up a maintenance dose.
  • Counting review intervals as 1 day when the product information sets a minimum of 2 days.

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 methyldopa dose?

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

How should I check the answer?

Fix the daily frequency first, multiply by 250 mg for the daily milligrams, divide any stated milligram total by 250 for tablets, and cap the day at 3 g.

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.