[The study on the duration of treatment in the standard short course chemotherapy containing pyrazinamide].

Based on the results of a questionnaire for the tuberculosis specialists in the whole country, we investigated whether the standard short course chemotherapy containing pyrazinamide (four drugs regimen: HRZE/S) were given for adequate duration. The results of a questionnaire revealed that the duration of treatment was prolonged in 60% of 848 cases due to several reasons. The reasons for the longer duration of treatment were (1) complication of other disease, (2) delay in the improvement on chest X-ray, (3) delay in negative conversion of bacilli, (4) drug resistance, (5) patient's request, and (6) others. According to our own experience in the National Dohoku Hospital for the past four years, the duration of therapy was prolonged in 86% of cases treated with the four drugs regimen, and in 64% of cases with the three drugs regimen (HRE/S). Four drugs regimen was preferred for severer cases and the three drugs regimen for older patients. The reasons for the prolonged duration of treatment in our hospital were similar to those in the results of a questionnaire in the whole country. We recognized that the treatment was prolonged due to several meaningless reasons such as "no particular reason", "anxiety on relapse" and "patient's request". In order to decide the adequate duration of treatment, it is needed to know the relapse rate in cases with the short course chemotherapy and its relationship with complications. It is hoped to establish the guideline for tuberculosis treatment including the duration of treatment based on the results of detailed clinical studies.