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COPD Exacerbation — SCE Infectious Diseases MCQ

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EasyAntimicrobial StewardshipCOPD ExacerbationSCE Infectious Diseases

A 65-year-old man with COPD is admitted with an infective exacerbation. Sputum culture grows Moraxella catarrhalis producing beta-lactamase. He was started on oral Amoxicillin 500 mg TDS. Why might this be inadequate?

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Correct answer: E — Over 90% of M. catarrhalis isolates produce beta-lactamase rendering Amoxicillin ineffective; Co-amoxiclav or Doxycycline is more appropriate

M. catarrhalis is one of the most common causes of acute exacerbation of COPD. Over 90% of isolates now produce BRO beta-lactamase, rendering plain Amoxicillin ineffective. Co-amoxiclav (Amoxicillin/Clavulanate) restores activity by inhibiting the beta-lactamase. Alternatives include Doxycycline or a macrolide. Second- and third-generation cephalosporins are also effective. This is an important stewardship point — empirical Amoxicillin alone may not cover a significant proportion of COPD exacerbation pathogens.

Reference: NICE NG115 2019 – COPD; BNF 2024 – Moraxella catarrhalis