Treatment of isoniazid-resistant tuberculosis in southeastern Texas.
BACKGROUND
Isoniazid-resistant tuberculosis (INHr-TB) can be treated successfully with several treatment regimens. However, the optimal regimen and duration are unclear.


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


METHODS
Retrospective cohort study.


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


METHODS
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.


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.
Escalante
P
P
Sections of Pulmonary and Critical Care, Institute for the Study of Human Bacterial Pathogenesis, Baylor College of Medicine, Houston, TX, USA. Patricioe@aol.com
Graviss
E A
EA
Griffith
D E
DE
Musser
J M
JM
Awe
R J
RJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000995:Antitubercular Agents / Q000008:administration & dosage*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004334:Drug Administration Schedule; D004352:Drug Resistance, Microbial; D005260:Female; D006801:Humans; D007223:Infant; D007538:Isoniazid / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013781:Texas; D016896:Treatment Outcome; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy*
D000995:Antitubercular Agents; D007538:Isoniazid