High-dose ethambutol: its role in intermittent chemotherapy. A six-year study.

The outcome of 81 patients receiving supervised ambulatory treatment with twice-weekly isoniazid and ethambutol is reported. The patients were divided into 2 groups, one of which received its entire outpatient treatment with isoniazid and ethambutol, the other receiving isoniazid and ethambutol after initial treatment with isoniazid and streptomycin. In both groups, there was a 100 per cent favorable response at completion of therapy and no relapes detected among those patients followed after treatment. We compared our results with other studies of intermittent-supervised therapy and concluded that twice-weekly isoniazid and ethambutol given up to 18 months after an adequate phase of daily treatment is a highly effective and well-tolerated regimen.