The therapeutic scheme for initial pulmonary tuberculosis recommended by the SAEI is as follows: Initial phase, isoniazid, rifampin and pyrazinamide given daily for 2 months. In HIV(+) patients and immigrants from areas with a rate of primary resistance to isoniazid > 4%, ethambutol should be added until susceptibility studies are available. Second phase (continuation phase): rifampin and isoniazid, given daily or intermittently for 4 months in the general population. HIV(+) patients (< or = 200 CD4) and culture-positive patients after 2 months of treatment should receive a 7-month continuation phase. A 6-month regimen is recommended for extrapulmonary tuberculosis, with the exception of tuberculous meningitis, which should be treated for a minimum of 12 months and bone/joint tuberculosis, treated for a minimum of 9 months. Treatment regimens for multidrug resistant tuberculosis are based on expert opinion. These would include a combination of still-useful first-line drugs, injectable agents, and alternative agents, such as quinolones. Patients who present a special risk of transmitting the disease or of non-adherence should be treated with directly observed therapy.