Amoxicillin Worsens Mortality from Viral Respiratory Tract Infection

Amoxicillin started during influenza A infection increases mortality and worsens secondary bacterial pneumonia severity in an animal model, with a more pronounced effect in males.

• Why it matters: Antibiotics are often prescribed during viral respiratory tract infections without microbiological data, but guidance is conflicting because prospective evidence is limited.
• What they did: The study developed an animal model to test antibiotic exposure during influenza A infection, comparing outcomes after amoxicillin initiation during infection.
• The result: Amoxicillin given during influenza A is linked to higher mortality and more severe secondary bacterial pneumonia, especially in males, informing antibiotic use during viral illness.