Multidrug resistance in TB is defined as resistance to
Multidrug Resistant TB (MDR-TB): Resistance to Isoniazid and Rifampicin “with or without resistance to other drugs‘

Treatment of MDR-TB must be done on the basis of sensitivity testing
Directly observed therapy certainly helps to improve outcomes and should be considered an integral part of the treatment of MDR-TB.

Extensive Drug Resistant TB (XDR–TB): Resistance to rifampicin and isoniazid as well as to any member of the quinolone family and at least one of the following second-line TB.
TB treatments: kanamycin, capreomycin, or amikacin.
Streptomycin, Rifampicin and Isoniazid
Isoniazid and Rifampicin
Streptomycin and Rifampicin
Streptomycin and Isoniazid