Metabolism of clofazimine in leprosy patients.
We have identified two metabolites of clofazimine (B663; Lamprene; 3-(p-chloroanilino)-10-(p-chlorophenyl)-2,10-dihydro-2-isopropyliminophenazine)  in our initial investigation of its metabolism in leprosy patients. Based on mass, ultraviolet, and visible spectrometry, we characterized an unconjugated (metabolite I, 3-(p-hydroxyanilino)-10-(p-chlorophenyl)-2,10-dihydro-2-isopropyliminophenazine ) and a conjugated (metabolite II, 3-(beta-D-glucopyranosiduronic acid)-10-(p-chlorophenyl)-2,10-dihydro-2-isopropyliminophenazine) metabolite from the urine of patients. Both metabolites were red in color, similar to clofazimine; however, both were considerably more polar than the parent drug. We suggest that metabolite I was formed by a hydrolytic dehalogenation reaction, and metabolite II by hydrolytic deamination followed by glucuronidation.
D002991:Clofazimine / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000378:metabolism* / Q000627:therapeutic use / Q000652:urine; D005260:Female; D006801:Humans; D007918:Leprosy / Q000188:drug therapy / Q000378:metabolism*; D008297:Male; D008954:Models, Biological
C033733:3-(4-hydroxyanilino)-10-(4-chlorophenyl)-2,10-dihydro-2-isopropyliminophenazine; C033734:3-(beta-D-glucopyranosiduronic acid)-10-(4-chlorophenyl)-2,10-dihydro-2-isopropyliminophenazine; D002991:Clofazimine