All of the following are bactericidal drugs except?
Ethambutol
Isoniazid
Rifampicin
Pyrazinamide
Ans. is 'a' i.e., Ethambutol All first line drugs are tuberculocidal except ethambutol which is tuberculostatic. Tuberculocidal - Rifampin, INH, streptomycin, pyrazinamide. Tuberculostatic - Ethambutol, PAS, cycloserine, thioacetazone.