[Which is the best drug combination for the short-term therapy of tuberculosis? A prospective randomized study with...

190 patients with positive cultures for M. tuberculosis were treated in the initial phase as inpatients for 2-3 months at random with either pyrazinamide (Z) or ethambutol (E) in combination with isoniazid (H) and rifampicin (R). In the continuation phase as out-patients they were treated by their family doctor for a further seven months with a new randomization using either R or E combined with H. Regular controls of drug intake using urine test strips were 97% positive. The patients treated with Z showed a tendency to more rapid conversion to negative cultures despite the significantly shorter duration of initial-phase treatment. During the average observation period of 33 months after commencing therapy there were five relapses (without development of drug resistance). The distribution over the four patient groups did not allow statistical conclusions to be drawn. All of the relapses occurred during the first year after the treatment ended. All relapsing patients showed an unusually long delay (108 days) before the tuberculosis cultures proved negative, in comparison with only 48 days in all patients. The relapse rate of 3.6% equals comparable controlled studies in the literature of the last four years, in which patients were initially hospitalized for two months or received medication under direct supervision as out-patients. The family doctors treated their patients on average for ten months instead of the nine months recommended in the treatment scheme ("doctor's compliance"). This seems to be a direct consequence of the earlier recommendations in favour of a longer duration of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)