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

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.