Therapeutic efficacy of rifampin in newly detected pulmonary tuberculosis.

A comparison was made of the therapeutic efficiency and tolerance of rifampin-based regimens and that of the standard triple-drug combination in the treatment of 92 newly diagnosed cases of pulmonary tuberculosis. The three drug regimens investigated were: A, rifampin-INH; B, rifampin-INH-streptomycin; and C, INH-PAS-streptomycin. Therapeutic progress was measured in terms of sputum conversion on culture and microscopy. The rifampin combinations produced a somewhat earlier sputum conversion. With regimens containing this potent antibiotic the phenomenon of microscopically-positive but culture-negative specimens was more frequently observed. The tolerance exhibited to the rifampin regimens was far greater than that to the conventional triple-drug combination. Nevertheless, periodic laboratory examinations are essential during rifampin therapy for safe utilization of the drug. An incidental finding of this study was the increase in primary resistance to streptomycin particularly among recent immigrants to Canada.