Two 8-month regimens of chemotherapy for treatment of newly diagnosed pulmonary tuberculosis: international multicentre randomised trial. (Study A)

A WHO-recommended 8-month regimen based on ethambutol and isoniazid was evaluated in a randomised clinical trial against a 6-month standard regimen. 1355 patients with newly diagnosed smear-positive pulmonary tuberculosis were randomly assigned one of three regimens: daily ethambutol, isoniazid, rifampicin, and pyrazinamide for 2 months, followed by ethambutol and isoniazid for 6 months (2EHRZ/6HE); the same drugs but given three times weekly in the initial intensive phase (2[EHRZ]3/6HE); or the same initial intensive phase as the first regimen, followed by 4 months of daily rifampicin and isoniazid (2EHRZ/4HR). Follow-up was to 30 months after the start of chemotherapy. Sputum was regularly examined by microscopy and culture. Unfavourable outcome was defined as failure during treatment or relapse afterwards. Analyses were by intention to treat.