Antibiotics showed no clear difference in all adverse events compared with placebo or usual care (low certainty).
Antibiotics showed no clear difference in adverse events ‐ overall (any adverse events not specified) compared with placebo overall (moderate certainty).
Antibiotic treatment showed no clear difference in all adverse events compared with placebo or no treatment (low certainty).
It is very uncertain whether any antibiotic regimen plus N‐acetylcysteine changes allergic adverse events compared with the same regimen without N‐acetylcysteine (with or without placebo) (very low certainty).