What is COPD?
COPD is a common chronic respiratory disease mainly affecting people who smoke now or have done so previously. It could become the third leading cause of death worldwide by 2030. People with COPD experience gradually worsening shortness of breath and cough with sputum because of permanent damage to their airways and lungs. Those with COPD may have flare-ups (or exacerbations) that usually occur after respiratory infections. Exacerbations may lead to further irreversible loss of lung function with days off work, hospital admission, reduction in quality of life and they may even cause death.
Why did we do this review?
We wanted to find out if giving antibiotics to prevent a flare-up, 'prophylactic' antibiotics, would reduce the frequency of infections and improve quality of life. Studies that were taken into consideration used either continuous prophylactic antibiotics on a daily basis or prophylactic antibiotics that were used intermittently.
What evidence did we find?
We found seven randomised controlled trials (RCTs) involving 3170 patients. All studies were published between 2001 and 2011. Five studies were of continuous antibiotics and two studies were of intermittent antibiotic prophylaxis. The antibiotics investigated were azithromycin, erythromycin, clarithromycin and moxifloxacin. On average, the people involved in the trials were 66 years old and had either moderate or severe COPD. Three trials included participants with frequent exacerbations and two of the trials recruited participants requiring systemic steroids or antibiotics, or both, or who were at the end stage of their disease and required oxygen.
Results and conclusions
We found that with the use of continuous daily antibiotics the number of patients who developed an exacerbation reduced markedly. For every eight patients treated, one person would be prevented from suffering an exacerbation. There may have been a benefit on patient-reported quality of life with the antibiotics. On the other hand, use of antibiotics did not significantly affect the number of deaths due to any cause, the frequency of hospitalisation, or the loss of lung function during the study period.
Even though there may be fewer exacerbations with continuous antibiotics there are considerable drawbacks. First, there were specific adverse events associated with the antibiotics, which differed according to the antibiotic used; second, patients have to take antibiotics regularly for years or months; finally, the resulting increase in antibiotic resistance will have implications for both individual patients and the wider community through reducing the effectiveness of currently available antibiotics.
Because of concerns about antibiotic resistance and specific adverse effects, consideration of prophylactic antibiotic use should be mindful of the balance between benefits to individual patients and the potential harms to society created by antibiotic overuse.