[Biliary, renal and fecal elimination and distribution of gold after a single oral administration of auranofin, quantified by the instrumental neutron activation analysis method].

Three days after cholecystectomy, seven patients received a single dose of auranofin (5 tablets Ridaura = 4.35 mg gold). At defined time points thereafter the gold content in samples of blood, plasma, urine, bile, and feces was determined by instrumental neutron activation analysis (INAA). Maxima of the mean gold concentrations in blood (140 +/- 42 ng/ml) and plasma (173 +/- 54 ng/ml) are found 2 h after oral administration of the antirheumatic agent, after 16 h in urine (43 +/- 28 ng/ml) and bile (65 +/- 50 ng/ml), and after 24 h in erythrocytes (greater than 200 ng/ml). The mean terminal half-lives are 7.6 days (blood), 15 days (plasma), 5 days (erythrocytes), and 6.5 days (bile). The cumulative biliary gold excretion within 8 days after the administration of auranofin was 1.6%, compared with 4% and 40% for renal and fecal elimination, respectively. The gold concentration in plasma is always higher than that in bile. There is a close correlation between the areas under the concentration curves (AUC) in bile and plasma (r = 0.864).