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Doxycycline counselling — GPhC CRA MCQ

Instant feedback + full explanation. One question, done properly.

ModerateInfectionsDoxycycline counsellingGPhC CRA

A 19-year-old man is prescribed doxycycline 100 mg daily for acne. He asks how to take it because he often takes supplements and goes to the gym before breakfast. What would you advise the patient?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: B — Take it with water while upright and separate from iron or zinc supplements

Doxycycline can irritate the oesophagus, so it should be taken with plenty of water while sitting or standing, avoiding lying down shortly after. Divalent and trivalent cations such as iron, zinc, calcium, and antacids can reduce absorption. Combining with isotretinoin without specialist supervision is inappropriate and increases safety concerns.

Reference: BNF; NICE CKS