[Chemotherapy with isoniazid and rifampicin for pulmonary tuberculosis]

Two-drug regimen of chemotherapy with isoniazid and rifampicin for pulmonary tuberculosis is the one of the standard methods of treatment for active pulmonary tuberculosis in Japan since 1996, while ATS/CDC and WHO/IUATLD recommended the three-drug or four-drug regimen containing chemotherapy pyrazinamide unless the prevalence of drug resistance, among new tuberculosis cases is low. We sent a questioners of 141 tuberculosis centers in Japan to investigate the rate of each standard chemotherapy regimen employed and reasons for selecting the two-drug regimen in each center. Of 3840 newly diagnosed cases in the 57 centers, 47.4% were treated with the four-drug regimen and 37.1% with the three-drug regimen, and two-drug regimen was employed in only 2.6%. Sputum smear-negative status was the major reason for selecting the two-drug regimen of chemotherapy. Though the two-drug regimen was used in few cases, taking into account the prevalence of primary resistance to isoniazid in Japan in 1997 was 4.4%, it was concluded to discontinue recommending the two-drug regimen as one of standard methods of treatment for pulmonary tuberculosis.