Anti-tuberculous Drug-induced Hepatotoxicity: A Retrospective Look onto Abu-Dhabi Tertiary Health Care Center Sheikh Khalifa Medical City (SKMC) Tuberculosis Patients Over a 7 Years’ Period

Background: The most effective tuberculosis treatment currently available is the 6-months course regimen utilizing isoniazid (INH), rifampicin (RIF), Ethambutol (ETB) and pyrazinamide (PYZ). The most serious side effect, which limits the use of these first line anti-tuberculosis medications, is hepatotoxicity, which may be fatal. TB is one of the commonest infectious diseases in the United Arab Emirates (UAE), due to the large number of immigrant workers from countries endemic for TB. Sheikh Khalifa Medical City (SKMC) is the largest tertiary care hospital in the UAE and cares for a majority of tuberculosis patients in Abu-Dhabi.

The Purpose: To find our incidence of DIH, risk factors for developing DIH and which drug of the known 4 anti-tuberculous medications caused more hepatotoxicity. We also looked at the patterns of AFB drug-resistance on cultures to report the incidence of single-drug and multi-drug resistant strains.

Design: A retrospective observational study of all tuberculosis patients admitted to SKMC in UAE between 2005-2011.

Results: 1047 tuberculosis patients admitted between 2005-2011, 450 were excluded and 597 were included in this study. The incidence of DIH was 3.2%, the risk factors for DIH were ethnicity (Asians were 63.2%), female gender (47%) and diabetes as a comorbidity. The majority of DIH cases happened in the first 2 weeks of treatment (58%), and INH was the commonest drug causing DIH among anti-TB medications (57%).

Conclusion: Tuberculosis remains more common in Asian immigrants among any diverse population like UAE and USA. Incidence of DIH in tuberculosis patients in our diverse, multi-national population was similar to that reported from USA, supporting the recommendation of liver function testing every two weeks from initiating ATT treatment up to one month, then monthly follow up until the end of the treatment course or if any new symptoms occur.