Which statement best guides antibiotic use when distinguishing acute bronchitis from COPD exacerbation?

• A. Antibiotics routinely given for acute bronchitis to prevent pneumonia.
• B. Antibiotics never used in COPD exacerbations.
• C. Acute bronchitis is usually viral and antibiotics are not routinely indicated; COPD exacerbations may require antibiotics if increased dyspnea and sputum changes.
• D. Antibiotics always indicated for both conditions.

Answer: (C)

Distinguishing when antibiotics are needed depends on the likely cause and the clinical signs that point to bacterial involvement. Acute bronchitis is typically viral, so antibiotics are not routinely indicated because they don’t shorten illness or prevent pneumonia and their overuse promotes resistance. In contrast, a COPD exacerbation can be driven by bacterial infection, and antibiotics are appropriate when there’s a clear signal of bacterial involvement—commonly increased dyspnea with changes in sputum, such as increased volume or purulence. This pattern aligns with guideline-based criteria that guide antibiotic therapy in COPD flares.

So, the statement recognizing that acute bronchitis is usually viral and antibiotics aren’t routinely used, while COPD exacerbations may require antibiotics if there is increased dyspnea and sputum changes, best reflects why antibiotics are appropriate in one scenario but not the other. The other options imply universal or universal-avoidance use, which does not fit real-world practice.