Rifampin in the treatment of pulmonary tuberculosis.

Rifampin is a newer semi-synthetic derivative of rifamycin. Its advantages over other derivatives are good oral absorption, high blood levels, and slower excretion rate. Rifampin has been studied in 68 patients and results can be summarized as follows:* There has been no evidence of significant toxicity.* In a randomized study of active tuberculosis patients who had not received prior chemotherapy, isoniazid-rifampin and isoniazid-aminosalicylic acid regiments were equally effective.* In retreatment patients with active, positive tuberculosis, the regimen of isoniazid, rifampin, and ethambutol proved to be very effective, especially when the two latter drugs had not been used previously.* In patients with pulmonary infections caused by atypical acid-fast bacilli, results varied with the organism isolated and the extent of disease. Rifampin is a potent, relatively non-toxic drug especially useful in the retreatment of pulmonary tuberculosis in patients who have never received this drug previously. There is little justification for its use in initial therapy except in rare cases.