Drug resistance antimycobacterial agents

Drug X is an antimycobacterial agent that inhibits other bacteria as well as poxviruses. However, It should not be used as a single agent because resistant mutants frequently form. The responsible mutation may alter the site of action of drug X [l.e., the deoxyribonucleic acid (DNA)-dependent ribonucleic acid (RNA) polymerase]. What Is drug X ... 

Capreomycin (capasiat) is an antimycobacterial cyclic peptide elaborated by Streptococcus capreolus. Bacterial resistance to capreomycin develops when it is given alone such microorganisms show cross-resistance with kanamycin and neomycin. Capreomycin is used only in conjunction with other appropriate drugs in treatment of pulmonary tuberculosis when bactericidal agents cannot be tolerated or when causative organisms have become resistant. 

F. Alternative Drugs The second-line antimycobacterial drags are used in cases that are resistant to first-line agents they are considered second-line drugs because they are no more effective, and their toxicides are often more serious than those of the major drags. 

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