Treatment of isoniazid-resistant tuberculosis in southeastern Texas

Chest. 2001 Jun;119(6):1730-6. doi: 10.1378/chest.119.6.1730.


Background: Isoniazid-resistant tuberculosis (INHr-TB) can be treated successfully with several treatment regimens. However, the optimal regimen and duration are unclear.

Study objective: To analyze the efficacy of treatment regimens used for INHr-TB in the southeastern Texas region.

Design: Retrospective cohort study.

Setting: Health-care facilities reporting tuberculosis (TB) patients in the Houston and Tyler areas.

Subjects: All patients reported to have INHr-TB from 1991 to 1998. Exclusion criteria included poor compliance, additional first-line drug-resistance (except aminoglycosides), and death before completion of 1 month of treatment.

Measurements and results: Main treatment outcomes were treatment failure, relapse, and TB-related death. Fifty-three of 83 patients were included in the study; aminoglycoside resistance coexisted in 37.5% of isolates. Seven types of treatment regimens were identified. Eighteen patients (34%) received rifampin, pyrazinamide, and ethambutol thrice weekly for 9 months. Four patients (7.5%) had a total effective treatment duration of < 9 months. Thirty patients (56.6%) and 16 patients (30.2%) received thrice-daily and daily treatment regimens, respectively. Forty-nine patients achieved sputum conversion. Treatment failure and death occurred in one patient (1.9%). Three patients (5.7%) experienced relapses. There was a significant difference in total effective treatment time between patients with and without relapses (8.3 +/- 1.1 months vs 11.1 +/- 2.1 months; p < 0.02). Twice-weekly treatment regimens were associated with relapse (p = 0.05).

Conclusions: Several treatment regimens were prescribed for INHr-TB in southeastern Texas. INHr-TB treatment durations were > 7 months, and treatment regimen efficacy was adequate. Twice-weekly treatment was associated with relapse, whereas thrice-weekly and daily treatments performed similarly. A prospective study with different treatment durations is needed to determine the optimal treatment regimen for patients with INHr-TB.

Publication types

  • Clinical Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Antitubercular Agents / administration & dosage*
  • Child
  • Child, Preschool
  • Cohort Studies
  • Drug Administration Schedule
  • Drug Resistance, Microbial*
  • Female
  • Humans
  • Infant
  • Isoniazid / pharmacology*
  • Male
  • Middle Aged
  • Retrospective Studies
  • Texas
  • Treatment Outcome
  • Tuberculosis, Pulmonary / drug therapy*


  • Antitubercular Agents
  • Isoniazid