Antibiotics for Acute COPD Exacerbations

8 for mortality

Benefits in NNT

1 in 8 were helped (life saved)
1 in 3 were helped (preventing failed treatment)
88.4% saw no benefit
11.6% were helped by being saved from death

Harms in NNT

1 in 20 were harmed (diarrhea)
5% were harmed by developing diarrhea
View As:

Efficacy Endpoints

Mortality, Treatment Failure (Lack of resolution, worsening, or death)

Harm Endpoints



Chronic obstructive pulmonary disease (COPD), a term that encompasses both patients diagnosed with chronic bronchitis and emphysema, is an obstructive lung disease, in many cases caused by tobacco smoking. It is thought that patients with COPD ‘exacerbation’ (increased shortness of breath or change in their chronic cough and sputum) may benefit from antibiotics, though the reasons for this are not well elucidated.

Benefits: Benefits were robust. 11 randomized trials are included from this review, totaling 817 subjects. The data suggest that overall COPD exacerbations benefit from antibiotics – both by reducing subjects’ short term (1-2 week) mortality and by reducing the chance of treatment failure (not getting better or getting worse). Mortality was reduced by 11.6%, a NNT of 8—a number that held consistently across subgroups. Treatment failure was reduced by 30.7% (NNT of 3) but this seemed most applicable to hospitalized subjects. The best effects on primary outcomes likely apply to the sickest patients: those admitted to the hospital and to the intensive care unit.

Harms: Only two studies collected data on diarrhea (a common side effect of antibiotics): antibiotics increased the risk of developing diarrhea by 5.0%, for a NNH of 20.


It isn’t clear if this translates well, or to what degree, for outpatients (patients who don’t require hospitalization). In addition, many of these studies were conducted in the mid- to late-20th century, possibly with a sicker-than-average group. Also, rates of smoking and packs-per-day have since declined. It is possible that different bacteria may be involved today. These studies also had a varying definition of COPD and COPD exacerbation. Finally, some studies used clinical criteria to rule out pneumonia, instead of using x-ray evaluation.


Graham Walker, MD


August 19, 2010