MDR/RR tuberculosis — DTM&H MCQ

Correct answer: C — Fully oral WHO-recommended MDR/RR-TB regimen

The correct answer is C, the fully oral WHO-recommended MDR/RR-TB regimen. Rifampicin resistance detected on Xpert MTB/RIF defines RR-TB, which must be treated as multidrug-resistant TB regardless of isoniazid status, because rifampicin resistance predicts poor response to standard first-line therapy and drives further resistance if standard treatment is continued. With no prior exposure to bedaquiline, linezolid or pretomanid, no fluoroquinolone resistance, and a negative pregnancy test, this patient meets WHO eligibility criteria for the 6-month BPaLM regimen (bedaquiline, pretomanid, linezolid, moxifloxacin), which WHO now recommends over longer regimens for eligible MDR/RR-TB patients. This regimen is fully oral, shorter, and has superior efficacy and safety compared with older injectable-containing regimens. Why the other options are wrong: A. Rifampicin monotherapy with adherence support: the isolate is already rifampicin-resistant, so rifampicin would be ineffective and would only amplify resistance; adherence is not the problem here, drug resistance is. B. Ceftriaxone and azithromycin: these have no established role in first-line pulmonary TB treatment and are not part of any WHO or UK MDR/RR-TB regimen. E. Standard 6-month isoniazid-rifampicin regimen: this regimen relies on rifampicin, to which resistance has already been confirmed, so it would fail and promote amplification of resistance. D. Isoniazid preventive therapy: this is for latent TB infection prevention, not for active, microbiologically confirmed rifampicin-resistant pulmonary disease. Key point: any Xpert MTB/RIF-confirmed rifampicin resistance mandates management as MDR/RR-TB, and if bedaquiline, linezolid and pretomanid are all treatment-naive with no fluoroquinolone resistance and pregnancy excluded, the fully oral 6-month BPaLM regimen is the WHO-preferred choice.

Reference: WHO Consolidated Guidelines on Tuberculosis, Module 4: Treatment, Drug-Resistant Tuberculosis Treatment (2022, updated 2024/2025) - recommends the 6-month BPaLM regimen for eligible MDR/RR-TB patients without fluoroquinolone resistance and without prior exposure to bedaquiline, linezolid or pretomanid. https://www.ncbi.nlm.nih.gov/books/NBK588564/