Empiric Addition of Quinolones to First-Line Tuberculosis Treatment Is Associated With Increased Odds of XDR-TB

Zarir F. Udwadia, Palak P. Patel, Samridhi Sharma, Amita Gupta, Jeffrey Tornheim

Research output: Contribution to journalArticlepeer-review


Background: Multidrug-resistant tuberculosis (MDR-TB) represents a significant clinical and public health challenge worldwide. Out of concern for possible resistance, some providers prescribe first- and second-line tuberculosis treatment together before completing drug susceptibility testing (DST), which may increase emergent resistance. Methods: MDR-TB patients at an Indian referral center were enrolled in an observational cohort. Participants with drug susceptibility test (DST) results were categorized as prescribed fluoroquinolones, streptomycin, both, or neither with first-line treatment before DST. Odds of additional resistance to fluoroquinolones and aminoglycosides (XDR-TB) were calculated in association with empiric combined first- and second-line treatment before DST. Results: Of 494 participants, 130 (26.3%) received a fluoroquinolone or streptomycin with first-line drugs before DST. Odds of XDR-TB were associated with fluoroquinolone prescription before DST [odds ratio (OR): 2.19, 95% confidence interval (CI): 1.26–3.76). The association with XDR-TB persisted in multivariable analysis (adjusted OR: 2.43, 95% CI: 1.19-4.91). Combined empiric first- and second-line treatment before DST was not associated with eventual outcomes. Conclusion: Many participants received empiric combined first- and second-line drugs before DST, which was associated with XDR-TB. To minimize emerging resistance, treatment-associated side effects, and provide the best possible care, this approach should be discouraged in favor of early DST and DST-guided TB treatment.

Original languageEnglish (US)
Article number779084
JournalFrontiers in Tropical Diseases
StatePublished - 2022


  • drug resistance
  • drug susceptibility testing
  • emerging resistance
  • fluoroquinolone resistance
  • streptomycin
  • XDR/TB-extensively drug resistance of tuberculosis

ASJC Scopus subject areas

  • Infectious Diseases
  • Microbiology (medical)
  • Public Health, Environmental and Occupational Health


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