Mucolytic agents for chronic bronchitis or chronic obstructive pulmonary disease

Poole P, Black PN

Published Online:

February 17, 2010

Twenty-eight trials with 7042 participants were included in this review of trials. The evidence suggests that if patients take the medicines regularly through the winter months this could result in a 21% reduction in the number of exacerbations (approximately 0.5 fewer per year), especially in people not already taking inhaled corticosteroids. There is considerable variation between the results of different studies in this review that is not fully explained. These medicines do not alter the loss of lung function in COPD, but they are very safe and well tolerated.

Abstract (click to read)

Background:

Individuals with chronic bronchitis or chronic obstructive pulmonary disease (COPD) may suffer recurrent exacerbations with an increase in volume and/or purulence of sputum. Because of the personal and healthcare costs associated with exacerbations, any therapy that reduces the number of exacerbations is useful. There is a marked difference between countries in terms of prescribing of mucolytics depending on whether or not they are perceived to be effective.

Objectives:

To assess the effects of oral mucolytics in adults with stable chronic bronchitis or COPD.

Search strategy:

We searched the Cochrane Airways Group Specialised Register and reference lists of articles on eight separate occasions, the most recent being in September 2008.

Selection criteria:

Randomised trials that compared oral mucolytic therapy with placebo for at least two months in adults with chronic bronchitis or COPD. We excluded studies of people with asthma and cystic fibrosis.

Data collection and analysis:

One review author extracted data. We contacted study authors and drug companies for missing information.

Main results:

Twenty-eight trials involving 7042 participants were included. Compared with placebo, there was a significant reduction in the number of exacerbations per patient with oral mucolytics (weighted mean difference (WMD) -0.04 per month, 95% confidence interval -0.05 to -0.03). Using a weighted annualised rate of exacerbations in the control patients of 2.4 per year, this is a 21% reduction. The number of days of disability also fell (WMD -0.56, 95% confidence interval (CI) -0.77 to -0.35). One recent study has shown that the benefit may apply only to patients not already receiving inhaled corticosteroids. The number of patients who remained exacerbation-free was greater in the mucolytic group (odds ratio (OR) 1.93 (95% CI 1.71 to 2.17)). There is no strong evidence of improvement in lung function and treatment is not associated with any increase in adverse effects. Patients on mucolytics may be less likely to be hospitalised during the study period.

Authors' conclusions:

In participants with chronic bronchitis or COPD, treatment with mucolytics was associated with a small reduction in acute exacerbations and a reduction in total number of days of disability. Benefit may be greater in individuals who have frequent or prolonged exacerbations, or those who are repeatedly admitted to hospital with exacerbations with COPD. Mucolytics should be considered for use, through the winter months at least, in patients with moderate or severe COPD in whom inhaled corticosteroids (ICS) are not prescribed.

This record should be cited as:

Poole P, Black PN. Mucolytic agents for chronic bronchitis or chronic obstructive pulmonary disease. Cochrane Database of Systematic Reviews 2010, Issue 2. Art. No.: CD001287. DOI: 10.1002/14651858.CD001287.pub3

Assessed as up to date:

November 1, 2008

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Primary Review Group:

Airways Group

Health topics:

Lungs & airways > Chronic obstructive pulmonary disease (stable) > Other medications

Cochrane Summaries^beta

Independent high-quality evidence for health care decision making

Mucolytic agents for chronic bronchitis or chronic obstructive pulmonary disease

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