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Beta-Lactamase H. influenzae — SCE Infectious Diseases MCQ

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EasyRespiratory InfectionBeta-Lactamase H. influenzaeSCE Infectious Diseases

A 60-year-old man with COPD develops acute exacerbation with purulent sputum. He has had 3 exacerbations in the past year, each treated with Amoxicillin. Current sputum culture grows Haemophilus influenzae with beta-lactamase production. What oral antibiotic is most appropriate?

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Correct answer: E — Co-amoxiclav 625 mg TDS for 5 days

Beta-lactamase-producing H. influenzae is resistant to Amoxicillin. Co-amoxiclav (Amoxicillin plus Clavulanic acid) restores activity by inhibiting the beta-lactamase. This is the recommended step-up for AECOPD when Amoxicillin-resistant H. influenzae is identified. Doxycycline is an alternative. Cefalexin (first-generation cephalosporin) has poor H. influenzae activity. For patients with frequent exacerbations, sputum culture guidance is important to direct targeted therapy and avoid unnecessary broad-spectrum use.

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