Acute exacerbations of chronic obstructive pulmonary disease (COPD) refer to a condition of sudden worsening of COPD symptoms, including shortness of breath or color of phlegm. Several studies have suggested that beta-blockers, like metoprolol, may reduce the risk of acute exacerbations in COPD patients. This study aims to evaluate the efficacy of metoprolol in preventing acute exacerbations in patients with COPD.

 This prospective, randomized trial included a total of 532 patients aged 40-85 years with COPD. The patients were assigned in a 1:1 ratio to receive either extended-release metoprolol or placebo. The primary outcome of the study was the time until the first exacerbation of COPD during the treatment period.

The findings suggested no significant between-group difference in the median time until the first exacerbation (202 in metoprolol vs. 222 in placebo). In addition, metoprolol was associated with an increased risk of exacerbation leading hospitalization (hazard ratio 1.91). The incidence of treatment-related adverse events was similar in the two groups. A total of 11 deaths in the metoprolol group and 5 in the placebo group were reported during the treatment period.

The research concluded that COPD did not show a significant increase in time until the first COPD exacerbation, as compared with the placebo.