# Side Effects of First-Line Anti-tubercular Therapy (ATT): Does an Alternative Regimen Exist?

## TL;DR

This study explores alternative tuberculosis treatment regimens when standard therapy causes side effects, finding that modified regimens can still lead to improvement.

## Contribution

The study evaluates the effectiveness of non-standardized anti-tubercular therapy regimens in patients with adverse drug reactions.

## Key findings

- Drug-induced liver injury and gastrointestinal intolerance were the main reasons for non-standard ATT.
- 76% of patients showed clinical improvement after the intensive phase of non-standard regimens.
- 60.1% of patients had radiological resolution by the end of the intensive phase.

## Abstract

Setting

Standard anti-tubercular therapy (ATT) typically involves a regimen of 2 months of HRZE intensive phase, followed by 4 months of HRE continuation phase - 2HRZE/4HRE (H-isoniazid, R-rifampicin, Z-pyrazinamide, E-ethambutol). However, adverse effects and comorbidities often necessitate alternative non-standardized regimens.

Objective

The aim of the study was to identify and evaluate the use, rationale, and outcome of non-standardized ATT regimens in patients with drug-sensitive tuberculosis.

Method

Our prospective observational study included 148 patients at a tertiary care hospital who were prescribed non-standard ATT due to various adverse effects and associated medical comorbidities on or after presentation. Patients were followed up through the intensive phase (two months) of the Directly Observed Treatment, Short-course (DOTS) regimen only, and their progress was assessed before the onset of the continuation phase.

Results

The most common reasons for non-standardized ATT were drug-induced liver injury (DILI) - 53.4%(79), and gastrointestinal (GI) intolerance - 21.6% (32). HRE was the most frequently used alternative regimen prescribed to 35.1% (52) of patients. At the end of the intensive phase, 76% (108) of patients reported clinical improvement, and 60.1%(89) showed radiological resolution. Three patients passed away during the course of the study, while four were lost to follow-up. No adverse effects were observed with modified regimens.

Conclusion

Non-standardized ATT regimens are often necessary due to adverse drug reactions, particularly hepatotoxicity. Most patients experienced symptomatic and radiological improvement on a non-standardized ATT regimen.