What do systematic reviews say?

Antibiotics vs placebo or usual care

Antibiotics showed no clear difference in all adverse events compared with placebo or usual care (low certainty).

• Antibiotics for exacerbations of asthma 2018 · Cochrane Headline outcomes only
  OR 0.99 [0.69, 1.43]
  3 studies · 506 participants
  Low

Antibiotics vs placebo

Antibiotics showed no clear difference in serious adverse events WMD of compared with placebo (moderate certainty).

• Prophylactic antibiotic therapy for chronic obstructive pulmonary disease (COPD) 2018 · Cochrane Headline outcomes only
  OR 0.88 [0.74, 1.05]
  9 studies · 2978 participants
  Moderate

Antibiotics vs placebo overall

Antibiotics showed no clear difference in adverse events ‐ diarrhoea compared with placebo overall (moderate certainty).

• Antibiotics for exacerbations of chronic obstructive pulmonary disease 2018 · Cochrane Headline outcomes only
  OR 1.68 [0.92, 3.07]
  5 studies · 1099 participants
  Moderate

Antibiotics vs placebo or usual care

Antibiotics showed no clear difference in serious adverse events Duration 3 days to 3 weeks compared with placebo or usual care (low certainty).

• Antibiotics for exacerbations of asthma 2018 · Cochrane Headline outcomes only
  RD 0
  3 studies · 502 participants
  Low

Antibiotics vs placebo overall

Antibiotics showed no clear difference in adverse events ‐ overall (any adverse events not specified) compared with placebo overall (moderate certainty).

• Antibiotics for exacerbations of chronic obstructive pulmonary disease 2018 · Cochrane Headline outcomes only
  OR 1.2 [0.89, 1.63]
  6 studies · 1544 participants
  Moderate

28 days on/off antibiotic regimen vs 28 days on/off placebo regimen

28 days on/off antibiotic regimen showed no clear difference in serious adverse events compared with 28 days on/off placebo regimen (low certainty).

• Intermittent prophylactic antibiotics for bronchiectasis 2022 · Cochrane Headline outcomes only
  OR 1 [0.68, 1.46]
  Studies not reported
  Low

14 days on/off antibiotic regimen vs 28 days on/off antibiotic regimen

14 days on/off antibiotic regimen showed no clear difference in serious adverse events compared with 28 days on/off antibiotic regimen (moderate certainty).

• Intermittent prophylactic antibiotics for bronchiectasis 2022 · Cochrane Headline outcomes only
  OR 0.83 [0.37, 1.86]
  Studies not reported
  Moderate

14 days on/off antibiotic regimen vs 14 days on/off placebo regimen

14 days on/off antibiotic regimen showed no clear difference in serious adverse events compared with 14 days on/off placebo regimen (high certainty).

• Intermittent prophylactic antibiotics for bronchiectasis 2022 · Cochrane Headline outcomes only
  OR 0.92 [0.63, 1.33]
  Studies not reported
  High

Macrolides vs placebo

Macrolides showed no clear difference in serious adverse events compared with placebo (low certainty).

• Macrolide antibiotics for bronchiectasis 2018 · Cochrane Headline outcomes only
  OR 0.43 [0.17, 1.05]
  1 study · 89 participants
  Low

Macrolides vs placebo

Macrolides showed no clear difference in serious adverse events compared with placebo (low certainty).

• Macrolide antibiotics for bronchiectasis 2018 · Cochrane Headline outcomes only
  OR 0.49 [0.2, 1.23]
  3 studies · 326 participants
  Low

Fluoroquinolones vs amoxicillin

• Head‐to‐head trials of antibiotics for bronchiectasis 2018 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 83 participants
  Low

Polymyxins vs aminoglycosides

• Head‐to‐head trials of antibiotics for bronchiectasis 2018 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 20 participants
  Very low

Macrolides vs no intervention

The review found no eligible studies for this question.

• Macrolide antibiotics for bronchiectasis 2018 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Macrolides vs no intervention

The review found no eligible studies for this question.

• Macrolide antibiotics for bronchiectasis 2018 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Oral + inhaled dual therapy vs oral monotherapy

It is very uncertain whether oral + inhaled dual therapy changes serious adverse events. Outcome assessed on day 42 compared with oral monotherapy (very low certainty).

• Dual antibiotics for bronchiectasis 2018 · Cochrane Headline outcomes only
  OR 0.48 [0.08, 2.87]
  1 study · 53 participants
  Very low