Overview of standard short-course therapy for tuberculosis

Modern regimens for fully drug-susceptible tuberculosis (TB) have an initial cure rate of over 98% and a five-year relapse rate of under 1%.

Standard short-course therapy requires 2 months of treatment with isoniazid, rifampicin, ethambutol and pyrazinamide (the ‘intensive phase’), followed by a further 4 months of treatment with isoniazid and rifampicin (the ‘continuation phase’)1. Quinolones (eg moxifloxacin) are not part of standard short-course therapy and should not be used for fully drug-susceptible TB, except in patients with tuberculous meningitis and those with kidney or liver impairment.

Standard short-course therapy is only suitable if:

  • the bacteria are susceptible to isoniazid, rifampicin and pyrazinamide (for drug-resistant infection, see Treatment of drug-resistant tuberculosis)
  • the patient tolerates and adheres to the regimen
  • tuberculous meningitis or other central nervous system TB, and complicated musculoskeletal TB, have been excluded
  • extensive cavitation is not present on the initial chest X-ray.

Use of daily and intermittent drug regimens:

  • For pulmonary TB, use the daily regimen for at least the first 2 months of therapy2. The intermittent (three-times-weekly) regimen can be used in the continuation phase on the advice of a TB specialist, but only after the patient demonstrates a clear clinical response to 2 months of daily therapy.
  • Whenever it is used, intermittent therapy is generally restricted to adults, and should only be considered if directly observed therapy (DOT) is available.
  • For extrapulmonary TB, it may be reasonable to start intermittent therapy earlier in the treatment course (ie during the intensive phase) in selected patients with paucibacillary disease (eg TB lymphadenopathy).
  • Use the daily regimen for the entire treatment course in HIV-infected patients, multidrug-resistant TB, or when there is no smear conversion after 2 months of treatment.

Monitor response to treatment, and extend the duration of therapy if the response is not satisfactory. Monitor the patient’s weight and adjust drug doses if necessary. For more information, see Monitoring tuberculosis therapy.

Additional information on management of tuberculosis is covered in the following sections:

1 Ethambutol should be discontinued once susceptibility to isoniazid and rifampicin is confirmed, even if this is before 2 months of therapy have elapsed; continue ethambutol if susceptibility results are not available at 2 months.Return
2 Intermittent therapy (twice or thrice weekly therapy) is no longer endorsed by the World Health Organization due to higher failure rates compared with daily therapy, particularly when intermittent therapy is used in the intensive phase.Return