A 60-year-old man with COPD presenting with an acute bacterial exacerbation is penicillin-allergic; which first-line antibiotic is most appropriate?

A 60-year-old man with COPD presenting with an acute bacterial exacerbation is penicillin-allergic; which first-line antibiotic is most appropriate?

• A. Azithromycin
• B. Doxycycline
• C. Amoxicillin
• D. Levofloxacin

Answer: (B)

In COPD acute bacterial exacerbations, antibiotics are chosen to reliably cover the common respiratory pathogens (Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae) while avoiding beta-lactams in penicillin-allergic patients. Doxycycline fits this need because it has good activity against these typical pathogens and also covers atypicals, with excellent lung penetration and a favorable safety profile. It provides effective outpatient first-line therapy without using a beta-lactam, which is important for someone with a penicillin allergy. Other options either rely on beta-lactams (not suitable here) or involve broader-spectrum agents with more potential for resistance or adverse effects, making doxycycline the most appropriate first-line choice in this scenario.

In COPD acute bacterial exacerbations, antibiotics are chosen to reliably cover the common respiratory pathogens (Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae) while avoiding beta-lactams in penicillin-allergic patients. Doxycycline fits this need because it has good activity against these typical pathogens and also covers atypicals, with excellent lung penetration and a favorable safety profile. It provides effective outpatient first-line therapy without using a beta-lactam, which is important for someone with a penicillin allergy. Other options either rely on beta-lactams (not suitable here) or involve broader-spectrum agents with more potential for resistance or adverse effects, making doxycycline the most appropriate first-line choice in this scenario.