title: Oral mucolytic drugs for exacerbations of chronic obstructive pulmonary disease: systematic review.
abstract: OBJECTIVE
  To assess the effects of oral mucolytics in adults with stable chronic bronchitis and chronic obstructive pulmonary disease.
  
  
  METHODS
  Systematic review of randomised controlled trials that compared at least two months of regular oral mucolytic drugs with placebo.
  
  
  METHODS
  Twenty three randomised controlled trials in outpatients in Europe and United States.
  
  
  METHODS
  Exacerbations, days of illness, lung function, adverse events.
  
  
  RESULTS
  Compared with placebo, the number of exacerbations was significantly reduced in subjects taking oral mucolytics (weighted mean difference -0.07 per month, 95% confidence interval -0.08 to -0.05, P<0.0001). Based on the annualised rate of exacerbations in the control subjects of 2.7 a year, this is a 29% reduction. The number needed to treat for one subject to have no exacerbation in the study period would be 6. Days of illness also fell (weighted mean difference -0.56, -0.77 to -0.35, P<0.0001). The number of subjects who had no exacerbations in the study period was greater in the mucolytic group (odds ratio 2.22, 95% confidence interval 1.93 to 2.54, P<0.0001). There was no difference in lung function or in adverse events reported between treatments.
  
  
  CONCLUSIONS
  In chronic bronchitis and chronic obstructive pulmonary disease, treatment with mucolytics is associated with a reduction in acute exacerbations and days of illness. As these drugs have to be taken long term, they could be most useful in patients who have repeated, prolonged, or severe exacerbations of chronic obstructive pulmonary disease.
authors.affiliation: Department of Medicine, University of Auckland, Private Bag 92019, Auckland, New Zealand.
authors.forename: P J
authors.initials: PJ
authors.lastname: Poole
authors.forename: P N
authors.initials: PN
authors.lastname: Black
mesh_terms: D000208:Acute Disease; D000284:Administration, Oral; D001991:Bronchitis / Q000503:physiopathology / Q000517:prevention & control; D002908:Chronic Disease; D005100:Expectorants / Q000627:therapeutic use*; D006801:Humans; D008168:Lung / Q000503:physiopathology; D008173:Lung Diseases, Obstructive / Q000503:physiopathology / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic
chemical_list: D005100:Expectorants