Macrolide/Azalide therapy for nodular/bronchiectatic mycobacterium avium complex lung disease.
BACKGROUND
There is no large study validating the appropriateness of current treatment guidelines for Mycobacterium avium complex (MAC) lung disease. This is a retrospective single-center review evaluating the efficacy of macrolide/azalide-containing regimens for nodular/bronchiectatic (NB) MAC lung disease.


METHODS
Patients were treated according to contemporary guidelines with evaluation of microbiologic responses. Macrolide susceptibility of MAC isolates was done at initiation of therapy, 6 to 12 months during therapy, and on the first microbiologic recurrence isolate. Microbiologic recurrence isolates also underwent genotyping for comparison with the original isolates.


RESULTS
One hundred eighty patients completed > 12 months of macrolide/azalide multidrug therapy. Sputum conversion to culture negative occurred in 154 of 180 patients (86%). There were no differences in response between clarithromycin or azithromycin regimens. Treatment regimen modification occurred more frequently with daily (24 of 30 [80%]) vs intermittent (2 of 180 [1%]) therapy (P = .0001). No patient developed macrolide resistance during treatment. Microbiologic recurrences during therapy occurred in 14% of patients: 73% with reinfection MAC isolates, 27% with true relapse isolates (P = .03). Overall, treatment success (ie, sputum conversion without true microbiologic relapse) was achieved in 84% of patients. Microbiologic recurrences occurred in 74 of 155 patients (48%) after completion of therapy: 75% reinfection isolates, 25% true relapse isolates.


CONCLUSIONS
Current guidelines for macrolide/azalide-based therapies for NB MAC lung disease result in favorable microbiologic outcomes for most patients without promotion of macrolide resistance. Intermittent therapy is effective and significantly better tolerated than daily therapy. Microbiologic recurrences during or after therapy are common and most often due to reinfection MAC genotypes.
Department of Medicine, University of Texas Health Science Center at Tyler, Tyler, TX; Department of Microbiology, University of Texas Health Science Center at Tyler, Tyler, TX; Department of Pathology, University of Texas Health Science Center at Tyler, Tyler, TX.
Richard J
RJ
Wallace
Department of Microbiology, University of Texas Health Science Center at Tyler, Tyler, TX; Department of Medicine, University of Texas Health Science Center at Tyler, Tyler, TX.
Barbara A
BA
Brown-Elliott
Department of Microbiology, University of Texas Health Science Center at Tyler, Tyler, TX.
Steven
S
McNulty
Department of Medicine, University of Texas Health Science Center at Tyler, Tyler, TX.
Julie V
JV
Philley
Department of Microbiology, University of Texas Health Science Center at Tyler, Tyler, TX.
Jessica
J
Killingley
Department of Pathology, University of Texas Health Science Center at Tyler, Tyler, TX.
Rebecca W
RW
Wilson
Department of Microbiology, University of Texas Health Science Center at Tyler, Tyler, TX.
Deanna S
DS
York
Department of Pathology, University of Texas Health Science Center at Tyler, Tyler, TX.
Sara
S
Shepherd
Department of Medicine, University of Texas Health Science Center at Tyler, Tyler, TX. Electronic address: david.griffith@uthct.edu.
David E
DE
Griffith
D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D017963:Azithromycin / Q000008:administration & dosage*; D001987:Bronchiectasis / Q000188:drug therapy* / Q000382:microbiology; D017291:Clarithromycin / Q000008:administration & dosage*; D004269:DNA, Bacterial / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D006801:Humans; D008171:Lung Diseases / Q000188:drug therapy* / Q000382:microbiology; D018942:Macrolides / Q000008:administration & dosage*; D008297:Male; D015269:Mycobacterium avium Complex / Q000235:genetics / Q000302:isolation & purification*; D015270:Mycobacterium avium-intracellulare Infection / Q000188:drug therapy* / Q000382:microbiology; D017410:Practice Guidelines as Topic; D012008:Recurrence; D012189:Retrospective Studies; D013183:Sputum / Q000382:microbiology; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D018942:Macrolides; D017963:Azithromycin; D017291:Clarithromycin