title: Clinical characteristics and treatment outcomes of patients with isoniazid-monoresistant tuberculosis.
abstract: BACKGROUND
  Risk factors and treatment outcomes under program conditions for isoniazid (INH)-monoresistant tuberculosis have not been well described.
  
  
  METHODS
  Medical charts were retrospectively reviewed for all cases of culture-confirmed, INH-monoresistant tuberculosis ( n = 137) reported to the San Francisco Department of Public Health Tuberculosis Control Section from October 1992 through October 2005, and those cases were compared with a time-matched sample of drug-susceptible tuberculosis cases (n = 274)
  
  
  RESULTS
  In multivariate analysis, only a history of treatment for latent tuberculosis (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.5-6.4; P = .003) or for active tuberculosis (OR, 2.7; 95% CI, 1.4-5.0; P = .002) were significantly associated with INH-monoresistant tuberculosis. Of the 119 patients who completed treatment, 49 (41%) completed a 6-month treatment regimen. Treatment was extended to 7-12 months for 53 (45%) of the patients and to >12 months for 17 (14%). Treatment was most commonly extended because pyrazinamide was not given for the recommended 6-month duration (35 patients [29%]). Despite variation in treatment regimens, the combined end point of treatment failure or relapse was uncommon among patients with INH-monoresistant tuberculosis and was not significantly different for patients with drug-susceptible tuberculosis (1.7% vs. 2.2%; P = .73).
  
  
  CONCLUSIONS
  A history of treatment for latent or active tuberculosis was associated with subsequent INH monoresistance. Treatment outcomes for patients with INH-monoresistant tuberculosis were excellent and were no different from those for patients with drug-susceptible tuberculosis. However, new, short-course regimens are needed because a small proportion of patients completed the 6-month treatment regimen recommended by the American Thoracic Society, Centers for Disease Control and Prevention, and Infectious Diseases Society of America, primarily because of pyrazinamide intolerance.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, University of California-San Francisco, San Francisco GeneralHospital, 1001 Potrero Ave., San Francisco, CA 94110, USA. acattamanchi@medsfgh.ucsf.edu
authors.forename: Adithya
authors.initials: A
authors.lastname: Cattamanchi
authors.forename: Raymund B
authors.initials: RB
authors.lastname: Dantes
authors.forename: John Z
authors.initials: JZ
authors.lastname: Metcalfe
authors.forename: Leah G
authors.initials: LG
authors.lastname: Jarlsberg
authors.forename: Jennifer
authors.initials: J
authors.lastname: Grinsdale
authors.forename: L Masae
authors.initials: LM
authors.lastname: Kawamura
authors.forename: Dennis
authors.initials: D
authors.lastname: Osmond
authors.forename: Philip C
authors.initials: PC
authors.lastname: Hopewell
authors.forename: Payam
authors.initials: P
authors.lastname: Nahid
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology / Q000627:therapeutic use*; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D007538:Isoniazid / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000302:isolation & purification; D011718:Pyrazinamide / Q000009:adverse effects / Q000627:therapeutic use; D012495:San Francisco; D016896:Treatment Outcome; D014376:Tuberculosis / Q000188:drug therapy* / Q000382:microbiology / Q000503:physiopathology*
chemical_list: D000995:Antitubercular Agents; D011718:Pyrazinamide; D007538:Isoniazid