Date	Event	Description
28 March 2008	New search has been performed	Searches conducted.
19 February 2008	Amended	Converted to new review format.
3 October 2006	New citation required but conclusions have not changed	A subgroup analysis of infants under two years old was added because of reports of paradoxical bronchial congestion and obstruction in infants under two years old receiving carbocysteine and acetylcysteine for acute cough.