Productive Cough
Expectorants
Mucolytics
Comparison between Expectorants and Mucolytics
Two random controlled double blind trials (RCDBT) were assessed
for the efficacy of guaiphenesin or bromhexine. (Parvez et al., 1996)
In the first RCDBT, the patients had some form of chronic
bronchopulmonary disease, namely bronchiectasis or Chronic
Obstructive Pulmonary Disease (COPD). In the Guaiphenesin RCDBT,
each patient was given 300mg or a placebo qid for 14 days, whist
in the Bromhexine RCDBT, each patient was given 16mg or a placebo
qid for 18 days.
The objective results from the guaiphenesin trial indicated that
the active patients (those given guaiphenesin) maintained a steady
sputum volume over the 14 day period, whilst the placebo group
showed a steady decline. The difference at the end of the 14 days
(37%) between the active and placebo groups, was statistically
significant (p<0.05). The active group also produced a greater
reduction in the average cough intensity than the placebo. This
result was also significant (p<0.05). The number of coughing
attacks reduced significantly from baseline in both groups, but
there was no statistical difference in the reduction between the
groups. The subjective results form the patients indicated that
the ease of expectoration in the active group, improved greatly
by day 10. This was a highly significant improvement (p<0.01)
between the two groups.
The objective results from the Bromhexine trial indicated
that the active patients (those given Bromhexine) expectorated
sputum at a steady rate over the 18 day period, whilst the
placebo group did not. The difference between the two groups
was statistically significant (p<0.05) at day 4. There was
however, no difference between the two groups in cough
intensity or from the baseline.
Overall Parvez et al. concluded that guaiphenesin did not
promote cough or worsen unlike bromhexine, but did continue
to maintain a constant expectoration of sputum. This
indicated that a cough treated with guaiphenesin was more
effective than a cough treated with bromhexine.
