| 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  | 
             |