Assessment of age-related isoniazid hepatotoxicity during treatment of latent tuberculosis infection.

ABSTRACT

BACKGROUND: Since the introduction of new recommendations for the treatment of latent tuberculosis infection (LTB1) disregarding age as a limitation, increasing numbers of older individuals are expected to undergo treatment with isoniazid for the prevention of tuberculosis, raising the potential for an increase in isoniazid hepatotoxicity. OBJECTIVE: To compare the frequency of hepatotoxicity requiring withdrawal of isoniazid therapy for LTB1 in patients under and over 35 years of age, managed according to current practice guidelines. DESIGN: A retrospective analysis of 300 patients who underwent isoniazid therapy for LTB1 according to a protocol based on the current practice guidelines. SETTING: Public health clinic of Passaic County, NJMain outcome measures: The frequency of symptomatic isoniazid hepatitis in various age groups. RESULTS: Of 165 patients < 35 years of age, 3(2%) patients developed hepatitis (AST > 3 times the upper limit of normal). Of 135 patients > or = 35 years of age, 4(3%) patients developed hepatitis. Statistical comparison between the two groups failed to show a significant difference (p = 0.705). CONCLUSIONS: No difference was detected in the frequency of isoniazid hepatotoxicity between patients < 35 and > or = 35 years of age. Clinically monitored isoniazid therapy of LTB1 patients > or = 35 years of age may not predispose subjects to an increased risk of hepatotoxicity. Limitations of this work include the small sample size and the retrospective nature of the study.