Common Registration Assessment, Part 1

Voriconazole loading and maintenance tablet doses 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.

A clinician adjusting an intravenous drip under operating theatre lights
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 voriconazole 200 mg film-coated tablets states that therapy must start with a loading dose regimen in the first 24 hours: for patients 40 kg and above, 400 mg every 12 hours by mouth.

After the first 24 hours, the maintenance dose for patients 40 kg and above is 200 mg every 12 hours; for patients under 40 kg the loading dose is 200 mg every 12 hours and the maintenance dose is 100 mg every 12 hours.

The same information allows the maintenance dose to be increased when response is inadequate, or reduced by 50 mg steps when the higher dose is not tolerated; tablets come in 50 mg and 200 mg strengths.

Each question fixes the values needed for its arithmetic. Distinguish loading (first 24 hours) from maintenance (after the first 24 hours) in every answer. All prescriptions and patients here are fictional; these are revision materials, not for patient care.

The method

  1. Check the stated body weight against the 40 kg threshold.
  2. Apply the loading doses only to the first 24 hours.
  3. Switch to the maintenance dose after the first 24 hours.
  4. Build doses from 200 mg and 50 mg tablets, larger strength first.

Three practice questions

Work each one on paper first, then open the answer. All patients and prescriptions are fictional.

Question 1

A fictional adult weighs 70 kg and starts oral voriconazole. What loading dose does the product information give for the first 24 hours, and how many 200 mg tablets does the whole loading day use?

Show the answer

Answer: 400 mg every 12 hours; four tablets across the day

Working: At 40 kg and above the oral loading dose is 400 mg every 12 hours, so two doses are given in the first 24 hours. Each dose is 400 / 200 = 2 tablets, so 2 x 2 = 4 tablets in total.

Question 2

The same fictional adult moves to maintenance dosing. What is the maintenance dose, and how many 200 mg tablets does a 14-day maintenance course need?

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Answer: 200 mg every 12 hours; 28 tablets

Working: Maintenance at 40 kg and above is 200 mg every 12 hours, which is 1 tablet per dose. Two doses a day for 14 days gives 2 x 14 = 28 tablets.

Question 3

A fictional adult weighs 38 kg and starts oral voriconazole. What maintenance dose applies after the first 24 hours, and how is each dose built from 50 mg tablets?

Show the answer

Answer: 100 mg every 12 hours; two 50 mg tablets per dose

Working: Under 40 kg the maintenance dose is 100 mg every 12 hours. Each 100 mg dose is 100 / 50 = 2 tablets of the 50 mg strength.

eMC SmPC: Voriconazole Milpharm 200 mg film-coated tablets

https://www.medicines.org.uk/emc/product/2049/smpc

Where marks are lost

  • Continuing 400 mg twice daily after the first 24 hours; that is the loading dose, not maintenance.
  • Applying the 40 kg-and-above doses to a patient under 40 kg.
  • Forgetting that maintenance changes move in 50 mg steps, so the 50 mg tablet strength matters.

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?

Check the weight against 40 kg, apply loading only to the first 24 hours, then count maintenance tablets at 200 mg or 50 mg per tablet.

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.