Treatment Outcome of Combination Therapy Including Clarithromycin for Mycobacterium avium Complex Pulmonary Disease

Background/Aims: The frequency of nontuberculous mycobacteria pulmonary disease in HIV-negative patients is increasing; the most common pathogen in Korea is the Mycobacterium avium complex (MAC). However, few studies have evaluated the treatment outcome of MAC pulmonary disease in Korea. Methods: The efficacy of a clarithromycin-containing regimen for MAC pulmonary disease was studied in 42 patients treated for more than 6 months between January 2005 and December 2008. All patients were treated with a regimen consisting of clarithromycin, rifampin, and ethambutol. Streptomycin was added in 10 patients. Results: Among the 42 patients, a negative culture conversion was achieved in 33 (78.6%), and the median duration of treatment in these patients was 19 months (interquartile range [IQR], 16 to 22). Of the 33 patients with a negative culture conversion, 14 completed treatment. During the follow-up period (median, 10 months; IQR, 4 to 20) for the 14 patients, one relapsed at 24 months after treatment completion. The culture conversion rate was significantly higher in patients who were treated with more than 500 mg/day clarithromycin (87.1% vs. 54.5%, p = 0.038). Conclusions: The combined regimen including clarithromycin was effective against MAC pulmonary disease. High-dose clarithromycin of more than 500 mg/day may improve the outcome of patients with MAC pulmonary disease.