Drug interactions -- the influence of rifampicin and clofazimine on the urinary excretion of DDS.

Indication of an enhancing effect of Rifampicin on the urinary excretion of DDs has already been reported from this institution. Further observations on this aspect in 25 cases of lepromatous leprosy treated with a 15 day schedule of Rifampicin at a dose of 600 mg daily along with DDS are presented. The earlier findings that Rifampicin in the initial phase of administration enhance the urinary output of DDS are confirmed. An estimation of Rifampicin Creatinine levels in urine done concurrently also showed a quicker elimination of the drug in the earlier phase compared to later phases of the drug administration. As part of the study of drug interactions, the influence of Clofazimine administration on DDS metabolism was also studied. The findings indicate that Clofazimine does not exert any influence on DDs excretion by leprosy patients. The findings and their implications are discussed.