Methylxanthines for exacerbations of chronic obstructive pulmonary disease: meta-analysis of randomised trials

Objective To evaluate the addition of methylxanthines to standard treatments in patients presenting with acute exacerbations of chronic obstructive pulmonary disease (COPD). Design Meta-analysis of randomised controlled trials. Data source The Cochrane air-ways review group's COPD register. Two reviewers independently selected articles for inclusion, assessed methodological quality, and extracted data. Selection of studies Four trials met the inclusion criteria, with 169 patients. Main outcome measures Mean change in spirometry, clinical end points, symptom scores, and adverse events. Results Mean change in forced expiratory volume at one second at two hours was similar in methylxanthine and placebo groups but transiently increased with methylxanthines at three days. Non-significant reductions in admissions to hospital and length of stay were offset by a non-significant increase in relapses at one week. Changes in symptom scores did not reach significance. Methylxanthines caused more nausea and vomiting than placebo (odds ratio 4.6,95% confidence interval 1.7 to 12.6), and non-significant increases in tremor, palpitations, and arrhythmias were also observed. Conclusions The available data do not support the use of methylxanthines for the treatment of exacerbations of chronic obstructive pulmonary disease. Potential benefits of methylxanthines for lung function and symptoms were generally not confirmed at standard levels of significance, whereas the potentially important adverse events of nausea and vomiting were significantly increased in patients receiving methylxanthines.