A large nationwide cohort study in JAMA compared amoxicillin-clavulanate vs amoxicillin for acute sinusitis in >500,000 adults. Treatment failure was low (~3%) with no significant difference between groups (RR 0.96). However, broader-spectrum therapy increased secondary infections, including yeast and C. difficile.

The message is clear: narrow-spectrum amoxicillin remains a rational first-line choice for uncomplicated sinusitis—balancing efficacy, safety, and stewardship.

Sometimes, the quiet drug wins the loud debate.