Intermittent antibiotic therapy for nodular bronchiectatic Mycobacterium avium complex lung disease

Although intermittent, three-times-weekly therapy is recommended for the initial treatment of noncavitary nodular bronchiectatic Mycobacterium avium complex (MAC) lung disease, supporting data are limited.

To evaluate the clinical efficacy of intermittent therapy compared with daily therapy for nodular bronchiectatic MAC lung disease.

A retrospective cohort study of 217 patients with treatment-naive noncavitary nodular bronchiectatic MAC lung disease. All patients received either daily (n = 99) or intermittent therapy (n = 118) that included clarithromycin or azithromycin, rifampin, and ethambutol.

Modification of the initial antibiotic therapy occurred more frequently in the daily therapy group than in the intermittent therapy group (46 vs. 21%; P < 0.001); in particular, ethambutol was more frequently discontinued in the daily therapy group than in the intermittent therapy group (24 vs. 1%; P ≤ 0.001). However, the rates of symptomatic improvement, radiographic improvement, and sputum culture conversion were not different between the two groups (daily therapy vs. intermittent therapy: 75 vs. 82%, P = 0.181; 68 vs. 73%, P = 0.402; 76 vs. 67%, P = 0.154, respectively). In addition, the adjusted proportion of sputum culture conversion was similar between the daily therapy (71.3%; 95% confidence interval, 59.1-81.1%) and the intermittent therapy groups (73.6%; 95% confidence interval, 62.9-82.2%; P = 0.785).

These results suggest that intermittent three-times-weekly therapy with a macrolide, rifampin, and ethambutol is a reasonable initial treatment regimen for patients with noncavitary nodular bronchiectatic MAC lung disease. Clinical trial registered with www.clinicaltrials.gov (NCT 00970801).