MANEJO DA TUBERCULOSE DROGARRESISTENTE (TB-DR)

A transição para esquemas totalmente orais e o papel dos novos fármacos

Abstract

Drug-resistant tuberculosis (DR-TB) constitutes a major global public health threat, characterized by a high burden of undiagnosed and inadequately treated cases. In 2024, the WHO estimated 390,000 new cases of rifampicin resistance; however, only 44% were diagnosed and 42% initiated treatment, facilitating the transmission of resistant strains. In Brazil, although it is not among the countries with the highest DR-TB burden, warning signs are observed, such as high rates of treatment interruption for drug-susceptible tuberculosis, underdiagnosis, and reduced treatment success for DR-TB, in addition to a predominance of primary resistance. Social determinants strongly influence the occurrence of DR-TB, with significant economic impact on affected families.

Resistance can be classified as natural, acquired, or primary, resulting from genetic mutations, selective pressure due to inadequate management, and transmission of resistant bacilli. Additional mechanisms, such as drug efflux and target modification, contribute to intrinsic multidrug resistance. DR-TB is categorized as monoresistant, polyresistant, RR-TB, MDR-TB, pre-XDR, and XDR, with increasing therapeutic complexity.

Tuberculosis treatment requires regimens with high bactericidal and sterilizing activity, with rifampicin being the main first-line drug. Resistance to this medication implies the use of longer, more expensive, potentially more toxic, and less effective regimens. Recent advances include fully oral and shorter regimens, such as BPaL (bedaquiline, pretomanid, and linezolid), recommended in Brazil since December 2024.

The organization of the healthcare network in Brazil foresees management according to case complexity, with referral of people with DR-TB to specialized centers. Addressing DR-TB depends on timely diagnosis, treatment adherence, and intersectoral strategies aimed at mitigating social vulnerabilities.