Maximum sterilising action is shown by which anti TB drug ?

Ans. is 'a' i.e., Rifampicin There are three main propeies of antitubercular drugs :- Bactericidal activity (tuberculocidal activity). Sterilizing activity. Ability to prevent resistance Bactericidal activity Isoniazid and rifampicin are the most powerful bactericidal drugs, active against all populations of TB bacilli. Pyrazinamide and streptomycin are also bactericidal against ceain populations of TB bacilli. Sterilizing activity Sterilizing acitivity is the ability to kill all the bacilli in lesions as rapidly as possible. Rifampicin is the most potent sterilizing antitubercular drug. Pyrazinamide is also having sterilizing action. To prevent resistance Ethambutol and thioacetazone are used in association with more powerful drugs to prevent emergence of resistance.