Abstract
Background: Prevalence of multi drug resistant (MDR) TB in Mumbai is estimated to be as high as 24% among patients newly diagnosed with TB. Analysis of consecutive 238 Rif-resistant TB culture isolates at our institute in 2014 concluded that the five most effective drugs were second-line injectables, ethionamide, fluoroquinolones, para-amino salicylic acid (PAS) and clofazimine (Presented at ERS annual congress 2015).
Aim: To validate the above 5-drug-regimen in a cohort of Rif-resistant isolates.
Methods: From June to September 2015, 491 consecutive TB culture isolates were analysed and the adequacy of the above regimen was tested. An adequate regimen was one that met the WHO criteria of a minimum of 4 effective drugs. All drugs were weighted equally.
Results: Of 491 isolates, 259(52%) were Rif-resistant. The derivation and validation cohorts had similar drug susceptibilities (Figure 1).
A prescription with the above 5 drugs would result in 132(51%) patients being treated with at least 4 effective drugs, and 209(81%) being treated with a minimum of 3 effective drugs.
Conclusion: Prescribing the 5 most susceptible drugs failed to provide an effective regimen for almost half of our cohort. In the absence of line probe assays, we recommend the addition of drugs such as cycloserine or linezolid (untested here) for empiric treatment, while awaiting results of cultures and susceptibility tests.
- Copyright ©the authors 2016