Early results (at 6 months) with intermittent clarithromycin-including regimens for lung disease due to Mycobacterium avium complex

We initiated a prospective noncomparative trial of treatment for lung disea se due to Mycobacterium avium complex (MAC) in human immunodeficiency virus -negative patients, with a regimen of clarithromycin (1000 mg), rifabutin ( 300-600 mg), and ethambutol (25 mg/kg) administered 3 times per week. Fifty -nine patients were enrolled. Twelve (20%) were lost to follow-up, and 6 (1 0%) developed clarithromycin intolerance. The remaining 41 patients (69%) c ompleted the initial 6 months of therapy The sputum of 32 of these patients (78%) converted to negative. When results were compared with the sputum re sponse rates at 6 months in previous studies with a regimen including daily clarithromycin and regimens including intermittent (3 times per week) azit hromycin with the same companion drugs, no differences in treatment respons es were evident. Adverse reactions related to rifabutin were a major proble m, and for 24 (41%) of 59 patients the dosage was decreased or the drug was withdrawn. Intermittent (3 times per week) administration of clarithromyci n appears to be as effective as daily administration in effecting sputum co nversion in pulmonary MAC disease.