Clinical and physiological evaluation of mucolytic agents nebulized with soproterenol: 10 per cent N-acetylcysteine verus 10 per cent 2-mercaptoethane sulphonate.

In a controlled five-week cross-over study in 12 patients with chronic bronchitis, the effects of nebulized 10% N-acetylcysteine plus isoproterenol were compared with a new drug, sodium 2-mercaptoethane sulphonate, in 10% concentration also nebulized with isoproterenol. Both combinations were compared with a control aerosol of saline and a second control aerosol of saline plus isoproterenol. Both 10% 2-mercaptoethane sulphonate and 10% N-acetylcysteine were highly effective in thinning mucoid, mucopurulent or purulent sputum. Subjective improvement in these patients, however, was related to the isoproterenol rather than to the mucolytic agents. When nebulized with isoproterenol, neither mucolytic agent was associated with bronchospasm in any patient. Physical findings, spirometric values, and sputum volume were unaffected by these mucolytic agents.