Treatment of Nontuberculous Mycobacteria (NTM) Infections

Introduction to NTM Treatment

The American Thoracic Society recommends macrolide-based multidrug regimens as the cornerstone of therapy for most common NTM infections, requiring extended treatment until cultures remain negative for at least 12 months 1, 2, 3

For patients with Mycobacterium avium complex (MAC) pulmonary disease, a three-times-weekly regimen of clarithromycin or azithromycin, rifampin, and ethambutol is recommended 1, 4
For patients with fibrocavitary or severe nodular/bronchiectatic MAC disease, a daily regimen of clarithromycin or azithromycin, rifampin or rifabutin, and ethambutol with consideration of three-times-weekly amikacin or streptomycin early in therapy is recommended 1, 5
Azithromycin is preferred over clarithromycin due to better tolerance, fewer drug interactions, lower pill burden, and single daily dosing 6
For patients with disseminated MAC disease, therapy should include clarithromycin or azithromycin and ethambutol with or without rifabutin 2, 3
Prophylaxis for AIDS patients with CD4 counts <50 cells/μl using azithromycin 1,200 mg/week or clarithromycin 1,000 mg/day is recommended 3, 4
For patients with Mycobacterium kansasii pulmonary disease, a daily regimen of isoniazid, rifampin, and ethambutol is recommended 1, 4
For patients with Mycobacterium abscessus pulmonary disease, surgical resection of localized disease combined with clarithromycin-based therapy offers the best chance for cure 5, 7

For patients with NTM lymphadenitis, primarily treated by surgical excision with >90% cure rate 5, 7
For patients with skin and soft tissue infections, thorough surgical debridement is essential 9
Culture-directed antibiotic therapy based on susceptibility testing is recommended for skin and soft tissue infections 9

NTM species should be identified to the species level to guide appropriate therapy 2, 3
Susceptibility testing recommendations include testing for clarithromycin only for MAC, and testing for rifampin only for M. kansasii 2, 3, 4
Meeting diagnostic criteria for NTM disease does not automatically necessitate treatment - consider risks/benefits and disease severity 6, 10
Prevention of healthcare-associated NTM infections requires avoiding tap water exposure to surgical wounds, injection sites, and intravenous catheters 4, 5

Extended treatment duration leads to adherence challenges and medication side effects 10
Drug-drug interactions are common, especially in elderly patients with comorbidities 9
Close clinical and laboratory monitoring is necessary throughout treatment 9