Evaluation of a New Mucolytic Agent

¹ Associate in Medicine, Harvard Medical School; Research Associate, Thorndike Memorial Laboratory, Boston City Hospital, Boston
² Assistant Chief, Medical Service and Director, Cardiopulmonary Laboratory, Veterans Administration Hospital, West Roxbuty; Instructor in Medicine, Harvard Medical School
³ Research Assistant, Veterans Administration Hospital, West Roxbury

A controlled study was performed to determine whether an ascorbic acid-percarbonate-copper sulfate mixture would be of value in treating chronic bronchitis. A secondary purpose was to evaluate some methods of studying mucolytic agents. The drug Gumox was administered by inhalation to nine patients, each of whom on a different day also received isotonic saline solution as control material. The immediate physiologic effect of the drug mixture was not significantly different from that of the saline control, both being associated with comparable improvements in the one-second vital capacity (1-sec. VC), maximal expiratory flow rate (MEFR) and maximal voluntary ventilation (MVV). However, the delayed effect of the drug, registered one day after treatment, showed further improvement in all three functions tested, while these values following saline treatment had returned to or toward the starting baseline.

The mean viscosity (measured with the Brookfield cone-plate viscometer) of sputum expectorated by patients on drug or saline treatment was not significantly different from that produced on no treatment. However, sputum samples incubated for one hour at 37°C. with equal volumes of either saline or drug solution were generally less viscous than unincubated samples but not significautly different from each other. Neither patient treatment with drug or saline solution nor sputum incubation with drug or saline resulted in significant changes in sputum osmolality.

It is concluded that the drug may be of value in treating chronic bronchitis because a significant improvement in the 1- sec. VC was associated with its use. However, confirmation with observations over a longer period of time in a larger number of subjects, using a control of comparable osmolality seems desirable. The physiologic studies were considered more meaningful than the sputum viscosity and osmolality studies in assessing the value of a potentially useful drug for treating chronic bronchitis.