Drug used in Standard regimens for new TB patients
(presumed, or known, to have drug-susceptible TB)
Intensive phase treatment Continuation phase
2 months 4 months
HRZE regimen HR regimen
Isoniazid (H) Isoniazid (H)
Rifampicin (R) Rifampicin (R)
Pyrazinamide (Z)  
Ethambutol (E)  
streptomycin  
In tuberculous meningitis, ethambutol should be replaced by streptomycin.
(in settings where the level of isoniazid resistance among new TB cases
is high and isoniazid susceptibility testing is not done
(or results are not available) before the continuation phase begins
Intensive phase treatment Continuation phase
2 months 4 months
HRZE regimen HRE regimen
isoniazid isoniazid
rifampicin rifampicin
pyrazinamide ethambutol
ethambutol  
Table 1: Adapted from Treatment of tubercolosis: guidelines for national programmes. Fourth edition. World Health Organization. http://www.who.int/tb/features_archive/new_treatment_guidelines_may2010/en/index.html