Bactericidal action of pulsed exposure to rifampicin, ethambutol, isoniazid & pyrazinamide on Mycobacterium tuberculosis in vitro.

ABSTRACT

The bactericidal action of pulsed exposure to rifampicin (R), ethambutol (Emb), isoniazid (I) and pyrazinamide (Z) together on alternate days (REmbIZ) and as REmb and IZ separately on alternate days (REmb/IZ) on M.tuberculosis H37Rv, two isolates of M.tuberculosis sensitive to these drugs, as well as four isolates resistant to one or more drugs, was studied using an in vitro method. The experimental duration was 6 days. REmbIZ and REmb/IZ appeared to have equally good bactericidal action on M.tuberculosis strains in the in vitro system. The results suggest that splitting REmbIZ into REmb and IZ on alternate days in short course chemotherapy regimens for tuberculosis may not affect the bactericidal action of the regimens.