Treatment of Pulmonary Mycobacterium avium Complex Lung Disease in Non-Acquired Immunodeficiency Syndrome (AIDS) Patients in the Era of the Newer Macrolides and Rifabutin

It is likely that the incidence and prevalence of lung disease caused by Mycobacterium avium complex (MAC) have been underestimated in the past. An explanation for the apparent increase in MAC lung disease can be found in the recent recognition that MAC may present as noncavitary lung disease in elderly nonsmoking women, in addition to the well-recognized cavitary form of disease seen primarily in men with underlying obstructive lung disease. Both forms of MAC lung disease can be progressive if left untreated. Previous therapy for MAC lung disease using only antituberculosis drugs was unsatisfactory. The most important advances in the treatment of MAC lung disease have been the introduction of the newer macrolide, clarithromycin; the closely related azalide, azithromycin; and rifabutin, a rifamycin similar to rifampin. Although effective, multidrug treatment regimens—including regimens that incorporate these agents—are associated with frequent adverse events and significant drug interactions that require close monitoring of patients. Even with better antimycobacterial agents, some patients with MAC lung disease do not respond to therapy. Further improvements in treatment of MAC lung disease are still needed.