[Effect of combined chemotherapy following the guidelines on treatment for Mycobacterium avium complex pulmonary disease]

We retrospectively investigated the clinical appropriateness of combined chemotherapy following the Japanese Society for Tuberculosis guidelines corresponding with those of the American Thoracic Society guideline for MAC pulmonary disease including a comparison with the past treatment for MAC pulmonary disease. The subjects of this study were 159 patients at several hospitals surveyed by the Chugoku-Shikoku Research Committee on Mycobacterium who were diagnosed as having MAC pulmonary disease between April 1995 and March 2001. Among them, 102 patients were treated using a regimen of antituberculous drugs with CAM, 33 patients received antituberculous drugs without CAM, and 24 patients were treated using other regimens. With a regimen of antituberculous drugs plus CAM, the sputum conversion rate was 45.1%, the relapse rate was 39.1% and clinical improvement was obtained in only 29.4%. On a regimen of only antituberculous drugs, the sputum conversion rate was 30.3%, the relapse rate was 70.0% and clinical improvement was obtained in 12.1%. Among the 102 patients receiving the regimen of antituberculous drugs plus CAM, 41 patients were treated with RFP, EB, SM and CAM following exactly the guidelines. The sputum conversion rate was 58.5%, the relapse rate was 37.5% and clinical improvement was obtained in 36.6%. Among 61 patients treated with other antituberculous drugs plus CAM, the sputum conversion rate was 36.1%, the relapse rate was 40.9% and clinical improvement was obtained in 24.6%. The clinical effect of the combined chemotherapy (RFP, EB, SM and CAM) was better than that of the other regimens throughout this study. However, the efficacy of this combined chemotherapy was unsatisfactory compared with the clinical effect for pulmonary tuberculosis. Therefore, the development of new companion drugs for the disease with mycobacteria other than M. tuberculosis is needed.