Most important drug for persistors of TB :

Rifampicin (RMP) RMP is a powerful bactericidal drug. It is a better sterilizing agent than INH. It permeates all tissue membranes including the blood – brain and placental barriers. It is equally effective against intracellular as well as extracellular bacilli. It is the only bactericidal drug active against the “persisters” or dormant bacilli which are found in the solid caseous lesions, all other drugs being inactive. In this regard, it has a distinct advantage over INH. Rifampicin is of special value when the bacilli resists other drugs. In combination with INH, it can cure even extensive tuberculosis in about 9 months.