Categories of treatment regimens prescribed for US hospital-based patients with laboratory-confirmed Mycobacterium avium complex (MAC)

Treatment regimens meeting ATS/IDSA guidelines [2]Macrolide, ethambutol and rifamycin, optional parenteral aminoglycoside#
Treatment regimens that potentially promote macrolide resistance [15]Macrolide monotherapy
Macrolide plus fluoroquinolone
Macrolide plus rifampin
Treatment regimens that are of unknown clinical significance [2]Macrolide plus inhaled amikacin
Macrolide plus linezolid
Macrolide plus other agents
Treatment regimens that do not include macrolidesEthambutol plus rifamycin
Fluoroquinolone-based regimen
Parenteral aminoglycoside-based regimen
Linezolid-based regimen

Regimens focused on antimicrobials containing potentially active compounds targeting MAC. Drugs that had no efficacy against nontuberculous mycobacteria were not included in this analysis. ATS: American Thoracic Society; IDSA: Infectious Disease Society of America. #: aminoglycosides include amikacin and streptomycin; receiving these drugs qualified as “meeting guidelines” regardless of additional antibiotics received; : “alternative macrolide therapy”; see online supplementary table S2 for macrolide combinations.