drug-resistant tuberculosis extensively drug-resistant tuberculosis GARD:0026240 XDR-TB A type of drug-resistant tuberculosis that is resistant to any fluoroquinolone, and at least one of three second-line injectable drugs (capreomycin, kanamycin, and amikacin), in addition to resistance to rifampicin and isoniazid. MEDGEN:321809 UMLS:C1827301 MONDO:0100482 MESH:D054908 NCIT:C128417