Enhanced expectoration of sputum may lead to a reduction in exacerbations of chronic obstructive pulmonary disease (COPD). Mucolytics are oral medicines that increase expectoration of sputum by reducing its viscosity.

The purpose of new study published in The Cochrane Database of Systemic Reviews were – to determine whether treatment with mucolytics reduces exacerbations and/or days of disability in patients with chronic bronchitis or COPD; to assess whether mucolytics lead to improvement in lung function or quality of life; and to determine frequency of adverse effects associated with use of mucolytics. 

Findings from 28 studies including 6 723 participants showed that patients receiving mucolytics may be more likely to be exacerbation-free during the study period compared to those given placebo. On the other hand, the type or dose of mucolytic did not seem to alter the effect size, nor did the severity of COPD, including exacerbation history. While longer studies depicted smaller effects of mucolytics than were reported in shorter studies. Mucolytic use was associated with a reduction of 0.43 days of disability per participant per month compared to the use of placebo. Additionally, the incidence of hospitalizations was lower among the group receiving mucolytics – moderate-certainty evidence. Investigators reported improved quality of life and reduced adverse events with mucolytics. However, no clear difference was noted between mucolytics and placebo for mortality.

It was concluded that in participants with chronic bronchitis or COPD, treatment with mucolytics leads to a small reduction in the likelihood of having an acute exacerbation, in days of disability per month and possibly hospitalizations. 

Source: The Cochrane Database of Systemic Reviews. 2019 May 20;5(5):CD001287. doi: 10.1002/14651858.CD001287.pub6.