Common Registration Assessment, Part 1
Fexofenadine tablet strengths by age for the GPhC assessment
Three original practice questions, with the working shown. Read the stated prescription or plan before calculating.
Published 17 October 2026. Independent revision material, not GPhC questions, not for patient care.
The NHS lists fexofenadine tablets in three strengths: 30 mg, 120 mg and 180 mg.
For hay fever the usual dose is 120 mg once a day for adults and children aged 12 and over, and 30 mg twice a day for children aged 6 to 11, spaced 10 to 12 hours apart. For hives the usual dose is 180 mg once a day for adults and children aged 12 and over.
Each question fixes the values needed for its arithmetic. Write the unit beside every step and keep a daily total separate from a supply. All prescriptions and patients here are fictional; these are revision materials, not for patient care.
The method
- Identify the exact strength, dose, frequency and age band supplied in the question.
- Calculate one dose first, then the daily total from the stated frequency.
- For tablets divide prescribed mg by mg per tablet.
- Scale to the stated duration only when a total supply is requested.
- Check the strength matches the stated age band before reporting.
Three practice questions
Work each one on paper first, then open the answer. All patients and prescriptions are fictional.
Question 1
A fictional prescription specifies fexofenadine 30 mg twice a day for a 9 year old, using 30 mg tablets. How many tablets are needed for 7 days?
Show the answer
Answer: 14 tablets
Working: One 30 mg tablet per dose, twice a day: 2 tablets a day. 2 × 7 = 14 tablets.
Question 2
A fictional prescription specifies fexofenadine 120 mg once a day for hay fever. How many 120 mg tablets are needed for 30 days?
Show the answer
Answer: 30 tablets
Working: One 120 mg tablet a day for 30 days: 1 × 30 = 30 tablets.
Question 3
A fictional prescription specifies fexofenadine 180 mg once a day for hives. How many days does a pack of 30 tablets of 180 mg last, and what total mg is taken over those days?
Show the answer
Answer: 30 days, 5,400 mg
Working: One tablet a day, so 30 tablets last 30 days. 180 × 30 = 5,400 mg.
Exam approach
Fix the age band first, because it decides the strength and frequency. A twice-daily supply doubles the tablet count of a once-daily one.
Where marks are lost
- Using the adult strength for a child age band stated in the question.
- Reporting a daily total when the question asks for the course.
- Treating arithmetic as evidence that a real prescription is clinically suitable.
Frequently asked questions
Are these official assessment questions?
No. They are original revision exercises, not official GPhC questions and not for patient care.
Why does the age band matter?
The usual strength and frequency differ by age band, so the stated band fixes the arithmetic.
How should I check the answer?
Check the requested unit, then work backwards from the quantity to the stated dose and duration.
Sources
- NHS: How and when to take fexofenadine
- GPhC, Common Registration Assessment specification and permitted items for 2026
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
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See also the formula sheet, the eight sample questions and the approved calculator page.