Gold concentrations and toxicity during oral gold treatment with auranofin

The concentrations of gold in whole blood, serum, urine and blood cells of patients with rheumatoid arthritis were measured during 6 months of oral treatment either with Auranofin or placebo. Any adverse effects attributable to the treatments were also recorded. Although the time course of gold during Auranofin therapy was similar to that of injected gold, the blood and serum gold concentrations were significantly lower than those measured in patients receiving injected gold. Between 45 and 58% of Auranofin gold in the blood was associated with blood cells. In comparison, following injections of gold thiomalate, only about 4% of the gold was present in the blood cells. During the 6-month period, 2 patients receiving Auranofin withdrew because of diarrhoea and another because of rash. 1 placebo patient withdrew because of headaches. No laboratory evidence of haematological, renal or hepatic abnormality was encountered. It is suggested that the markedly lower concentrations of gold in the body sustained during treatment with Auranofin may be the critical factor towards a greater tolerance of the drug in the treatment of rheumatoid arthritis.