Frequency of adverse events observed with second-line drugs among patients treated for multidrug-resistant tuberculosis

Abstract

Background: Multidrug-resistant tuberculosis (MDR-TB) is considered to be a worldwide problem with notoriously difficult and challenging treatment. Adverse events associated with second-line drugs (SLDs) can have severe impact on efficient management.

Objective: To know the frequency of adverse events due to SLDs in patients of MDR-TB.

Design: A prospective cohort analysis of 98 MDR-TB patients enrolled between June 2009 to February 2010 was conducted in Department of Pulmonary Medicine, King George Medical University, Lucknow, India. All the patients were provided standardized regimen. Adverse events associated with treatment were recognized primarily by clinical evidence and/or laboratory investigations that were advised at baseline and whenever clinically indicated during course of treatment. Adverse events were considered major if required permanent discontinuation or substitution of drugs.

Results: 119 adverse events were reported in 46 (46.9%) patients. The grouped adverse events were most commonly gastrointestinal that was observed with a frequency of 48 (40.3%) followed by ototoxicity in 28 (23.6%), and neurological in 21 (17.6%). 17 (17.4%) patients had major adverse events requiring permanent discontinuation or substitution of drugs that included deafness and tinnitus in 5 (5.1%) followed by psychosis in 4 (4.1%). None of the patients stopped complete regimen due to adverse events. The treatment success rate was observed to be 71 (72.4%).

Conclusions: MDR-TB can be cured successfully with appropriate combination of drugs if adverse events associated with them can be managed aggressively and timely. Newer and less toxic drugs are urgently needed to treat MDR-TB patients.

Keywords: Adverse events; DOTS PLUS; Second-line drugs.