H. pylori infection — ESEGH MCQ

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EasyTreatment of Helicobacter pylori InfectionH. pylori infectionESEGH

A 48-year-old man with newly diagnosed H. pylori infection asks about clarithromycin-based triple therapy. Local surveillance data show clarithromycin resistance >15%, and his H. pylori susceptibility is unknown. Which is the most appropriate counselling?

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Correct answer: B — Avoid clarithromycin triple therapy unless susceptibility testing proves sensitivity

When local clarithromycin resistance exceeds approximately 15% and susceptibility is unknown, international consensus (Maastricht VI/Florence, UK gastroenterology guidance 2024) and UK antimicrobial guidance recommend avoiding clarithromycin-based therapy empirically. **Option B is correct** because it appropriately counsels avoidance until susceptibility is proven. **Option D is wrong**—clarithromycin triple therapy is no longer first-line when resistance >15%. **Option E is incorrect**—azithromycin shares macrolide cross-resistance with clarithromycin (~34% global resistance) and is not a suitable alternative. **Option A is misleading**—whilst metronidazole is used in quadruple regimens, simple substitution of metronidazole for clarithromycin in triple therapy is not the evidence-based approach and doesn't address the high local clarithromycin resistance. **Option C is wrong**—H. pylori eradication is clinically indicated. The discriminating feature is the >15% resistance threshold: above this, empirical clarithromycin is contraindicated regardless of whether susceptibility testing has been performed.

Reference: https://www.nice.org.uk/guidance/conditions-and-diseases/digestive-tract-conditions