All of the following are bactericidal drugs except-

Ans. is 'a' i.e., Ethambutol o All first-line drugs are tuberculocidal except ethambutol which is tuberculostatic. Tuberculocidal - Rifampin, INH, streptomycin, pyrazinamide. Tuberculostatic - Ethambutol, PAS, cycloserine, thioacetazone.