Prescrire Int. 2014 Oct;23(153):245-6.
Tuberculosis is said to be multi-drug-resistant (MDR-TB) when the mycobacterial strain is resistant to both isoniazid and rifampicin in vitro, and "extensively multidrug-resistant" (XDR-TB) when the strain is also resistant to fluoroquinolones and to at least one aminoglycoside or capreomycin. Multidrug resistance greatly increases the lethality of tuberculosis. Patients with multidrug-resistant tuberculosis are usually treated for at least 20 months with a combination of five antibiotics. For want of better alternatives, extensively resistant disease is often treated with antibiotics that have both uncertain efficacy and major adverse effects. Antitubercular drug combinations have multiple adverse affects and many drug interactions. In practice, the choice of drugs is usually empirical, being based on bacteriological criteria and using antibiotics with uncertain efficacy but documented harms.
当分枝杆菌菌株在体外对异烟肼和利福平均耐药时，结核病被称为耐多药结核病（MDR-TB）；当该菌株对氟喹诺酮类药物以及至少一种氨基糖苷类药物或卷曲霉素也耐药时，则被称为“广泛耐药结核病”（XDR-TB）。耐多药极大地增加了结核病的致死率。耐多药结核病患者通常要用五种抗生素联合治疗至少20个月。由于缺乏更好的替代方案，广泛耐药结核病往往使用疗效不确定且有严重不良反应的抗生素进行治疗。抗结核药物组合有多种不良反应和许多药物相互作用。在实际操作中，药物的选择通常是经验性的，基于细菌学标准，使用疗效不确定但有明确危害记录的抗生素。
