The Treatment of Human Pulmonary Tuberculosis With Cycloserine: Progress Report

Abstract

The discovery that streptomycin is an efficient antituberculosis drug revolutionized the treatment of pulmonary tuberculosis and has generated considerable optimism in regard to the outcome of this disease. Together with INH (isoniazid) or PAS (para-aminosalicylic acid) , it has been instrumental in saving innumerable lives. By promptly clearing the sputum of tubercle bacilli, it has made prolonged hospitalization unnecessary and has lessened the number of subjects who would otherwise have become infected by contact with the patient. The chronic toxicity of streptomycin for the eighth nerve made the discovery of isoniazid doubly welcome, because the drug was not very toxic and because it proved efFective in streptomycin-resistant cases. However, the rapid development of resistance by the tubercle bacilli to both streptomycin and INH has limited the usefulness of the drugs for a goodly proportion of cases. PAS, with its mild antituberculosis effects and its ability to delay the development of resistance to the other antimicrobial agents, extended the usefulness of both streptomycin and INH. The eventual emergence of resistance to the antimicrobial agents, despite the use of PAS, and the development of eighth nerve involvement, despite the use of reduced doses of streptomycin, left a hiatus in the treatment of tuberculosis for which there was no effective remedy. With the passage of time there has been an ever-increasing number of patients in sanatoria who have reached a limit of improvement with present antimicrobial therapy, and who, although they may retrogress upon discontinuance of treatment, do not continue to improve with it. For these reasons we were happy to have the opportunity to try the new antibiotic, cycloserine, in the treatment of a group of chronic cases who had reached a status quo with the other antimicrobial agents. A preliminary report on the use of cycloserine in the treatment of human pulmonary tuberculosis has been given elsewhere.1’ 2 TJp to that time cycloserine had been used on 37 cases, eight of whom were acute, previously untreated, and 29 chronic and clinically resistant to other antimicrobial