title: Factors related to response to intermittent treatment of Mycobacterium avium complex lung disease.
abstract: BACKGROUND
  Mycobacterium avium complex pulmonary disease (MAC-PD) is associated with substantial morbidity, and standard daily multidrug therapy is difficult to tolerate.
  
  
  OBJECTIVE
  To characterize response to a three-times-weekly (TIW) regimen of clarithromycin, ethambutol, and rifampin.
  
  
  METHODS
  A 1-yr prospective noncomparative trial of TIW treatment was conducted during 2000-2003 in 17 U.S. cities. Participants were 91 HIV-negative adults, diagnosed with moderate to severe MAC-PD, who originally participated in a trial of an inhaled IFN-gamma treatment. Improvement in sputum culture, high-resolution computed tomography (HRCT), and symptoms were assessed.
  
  
  RESULTS
  Treatment response rates (and median response times) were 44% (2 mo or longer) for culture, 60% (5.5-11.5 mo) for HRCT, and 53% (8.5 mo) for symptoms. Having noncavitary, compared with cavitary, disease increased culture response by 4.0 times (95% confidence interval [CI], 1.7-9.2) and HRCT response by 4.9 times (95% CI, 1.9-13.0). Culture response was 1.5 times (95% CI, 1.1-2.2) higher for older subjects and 2.2 times (95% CI, 1.0-4.7) higher for previously untreated subjects. Being smear-negative increased culture response by 2.3 times (95% CI, 1.1-5.2) but decreased HRCT response by 4.4 times (95% CI, 1.7-11.5). Increasing ethambutol use by 5 mo increased culture response by 1.5 times (95% CI, 1.0-2.1) but decreased symptom response. Not having chronic obstructive pulmonary disease, bronchiectasis, or poor lung function increased symptom response by 1.9 to 3.9 times.
  
  
  CONCLUSIONS
  TIW therapy was less effective for MAC-PD patients with cavitary disease and a history of chronic obstructive pulmonary disease, bronchiectasis, or previous treatment for MAC-PD. Further research is needed to study the long-term outcomes of TIW treatment.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, University of California, San Diego, San Diego, CA 92103-8374, USA.
authors.forename: Phung K
authors.initials: PK
authors.lastname: Lam
authors.forename: David E
authors.initials: DE
authors.lastname: Griffith
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Aksamit
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Ruoss
authors.forename: Stuart M
authors.initials: SM
authors.lastname: Garay
authors.forename: Charles L
authors.initials: CL
authors.lastname: Daley
authors.forename: Antonino
authors.initials: A
authors.lastname: Catanzaro
mesh_terms: D000368:Aged; D000995:Antitubercular Agents / Q000008:administration & dosage* / Q000009:adverse effects; D001987:Bronchiectasis / Q000188:drug therapy / Q000209:etiology; D017291:Clarithromycin / Q000008:administration & dosage* / Q000009:adverse effects; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D004977:Ethambutol / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D005540:Forced Expiratory Flow Rates; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D015269:Mycobacterium avium Complex; D015270:Mycobacterium avium-intracellulare Infection / Q000000981:diagnostic imaging / Q000188:drug therapy*; D011446:Prospective Studies; D011859:Radiography; D012293:Rifampin / Q000008:administration & dosage* / Q000009:adverse effects; D013183:Sputum / Q000382:microbiology; D016896:Treatment Outcome; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy* / Q000382:microbiology
chemical_list: D000995:Antitubercular Agents; D004977:Ethambutol; D017291:Clarithromycin; D012293:Rifampin