Multicompartmental analysis of serum, urine and bile concentrations of rifampicin and desacetyl-rifampioin in subjects treated for one week

Abstract

Summary o 1) A multicompartmental analysis of the serum, urine and bile concentrations of rifampicin and of its desacetyl-derivat i ve was carried out in man in order to assess the simultan e ous distribution of the two compounds during repeated trea t ment. 2) The results have shown that the desacetyl-derivative repr e sents only a small fraction of the antibiotic present in serum and that this fraction decreases with time. This finding suggests that the decrease in biological half-life observed in the early phase of continuous treatment with rifampicin involves the antibiotic in its unchanged form. 3) The decrease in the serum rifampicin levels was accompanied by an increased biliary excretion which involves mainly the metabolic derivative. 4) The kinetic analysis appeared to indicate that the rate of intestinal absorption of the antibiotic increases with time as does the rate of biotrasformation of rifampicin into d e sacetyl-rifampicin.