Adverse effects of isoniazid preventative therapy for latent tuberculosis infection: a prospective cohort study

Abstract

Introduction

Isoniazid preventative therapy (IPT) is a widely used intervention for treatment of latent tuberculosis infection (LTBI), particularly in patients at high risk for reactivation. While treatment-limiting adverse effects have been well studied, few prospective studies have considered the range of adverse effects that patients may experience with IPT.

Methods

All patients commencing treatment for LTBI were prospectively enrolled in an ongoing database of LTBI treatment outcomes particularly related to adverse effects, treatment adherence, and treatment completion.

Results

Data on the first 100 patients who were prescribed IPT are presented. Fifty-six patients reported at least one adverse effect at some stage during treatment, with six experiencing at least one World Health Organization (WHO) Grade 3–4 adverse effect. Increased age was significantly associated with risk of adverse effects (odds ratio [OR] =1.05 per year; confidence interval [CI] of 1.02–1.08=95%). Eighty-five patients had documented completion of therapy locally, with ten patients ceasing IPT due to adverse effects.

Discussion

This report highlights a variety of somatic adverse effects that occurred in a real-world cohort of patients receiving IPT. While adverse effects were frequently identified in this study, the considerable majority were low grade and transient. Despite frequent adverse effects of LTBI in our treatment cohort, the study demonstrated high levels of treatment adherence and completion.

Keywords:

• latent tuberculosis infection
• isoniazid preventative therapy
• treatment toxicity

Acknowledgments

We thank the John Burge Trust Fund for financial support towards latent tuberculosis research during the period of this review.

Disclosure

The authors report no conflicts of interest in this work.