Search

Free thiomalate is measureable in the plasma and urine of patients with rheumatoid arthritis receiving sodium aurothiomalate (Myocrisin). Plasma concentrations and urinary excretion of free thiomalate were measured in 8 patients by high-performance liquid chromatography and electrochemical detection. After an initial intramuscular dose of 20 mg sodium aurothiomalate, free thiomalate was detected in plasma within 15 min, peak levels of up to 600 nmol/l occurring at 30 min. Plasma levels declined rapidly thereafter. During the first 24 h between 2 and 16% of the injected dose of aurothiomalate was recovered in the urine as free thiomalate, maximum excretion occurring during the first hour.

The excretory fate and plasma level of thiomalate were studied after intramuscular administration of auro-14C-thiomalate to 3 patients with rheumatoid arthritis. The gold and the thiomalate parts separated in vivo, and the free thiomalate was excreted in the urine, rapidly at first and then slowly. After one day about 60% of the 14C-label had been recovered in the urine. The plasma level also declined rapidly. The results are in complete agreement with those previously described in animal experiments.