Short-course chemotherapy in pulmonary tuberculosis. A controlled trial by the British Thoracic and Tuberculosis Association.

A rigimen of rifampicin plus isoniazid, supplemented in the first two months by ethambutol or streptomycin, was given for six, nine, twelve, or eighteen months in a controlled study of 696 patients with culture-positive pulmonary tuberculosis. The results obtained in the thirty-three months since the start of treatment when all the patients in the six-month and nine-month groups had completed at least two years and those in the twelve-month group had completed twenty-one months of post-chemotherapy follow-up revealed no relapses among patients receiving nine months chemotherapy and a 1% relapse-rate in the twelve-month group. The same regimen given for only six months resulted in a relapse-rate of 5% during the subsequent twenty-seven months. There were adverse effects with streptomycin but not with ethambutol. It is concluded that treatment with rifampicin plus isoniazid for nine months, supplemented by ethambutol in a dose of 25 mg/kg for the first two months, is now acceptable as standard chemotherapy for pulmonary tuberculosis in Britain.