Abstract: Objective To compare the antituberculous activities of the Fixed-dose combination(FDC) in antituberculous made by different pharmaceutical companies and evaluate their potential contribution to treatment of tuberculosis. Methods The MICs of the FDC against M.tuberculosis H₃₇Rv、M.phlei and M.ravenal were determined by the tube doubling dilution method in vitro.The efficacy of antituberculosis was assessed by half survival time of the mice. Results In vitro, the MICs of main composition in the FDC(RFP,INH or RFP,INH PZA) against M.tuberculosis H37Rv、M.phlei and M.ravenal were lower than that of each composition used alone in the same media.In vivo,these FDC drugs had marked effect against experimental tuberculosis in mice and were superior to each agent used alone with the same dose. Conclusion The two-and three-drug FDC had significantly effective antituberculous activity.The same preparations from different companies had not significant difference in treatment of the mice infected with M.tuberculosis.

Key words: Isoniazid, Rifampicin, Pyrazinamide, AFDC, Tuberculosis