The subacute and chronic toxicity of SK&F 36914 and SK&F D-39162 in dogs

Effects of ligands on gold inhibition of selenium glutathione peroxidase

Gold inhibits selenium-dependent glutathione peroxidase (GSH Px) in vitro. Chrysotherapy has been used for over five decades without complete understanding of its pharmacodynamics. This study shows that gold is potentially an inhibitor of GSH Px in vivo. Reported are conditions for assay of GSH-Px activity showing that the inhibition by gold species can be reversed. The study demonstrates the high affinity of gold for the selenohydryl-active site of GSH Px relative to the affinities of other physiological ligands; GSH Px was inhibited to a greater extent by a small molecular-weight fraction isolated from kidneys of gold-treated rats than by the fraction isolated from kidneys of rats not treated with gold. The data provide a new perspective on the action of gold-containing drugs in vivo.

Auranofin: a unique oral chrysotherapeutic agent

Auranofin is a chemically unique gold coordination complex with demonstrated antiarthritic properties on oral administration. Its pharmacokinetic and immunologic profiles are distinct from injectable gold compounds. When auranofin is added to a regimen of salicylates and/or a nonsteroidal antiinflammatory drug for the treatment of RA, significant additional therapeutic benefit is observed. Published studies indicate that auranofin given 6 mg per day approaches the efficacy of parenteral gold salts in the treatment of rheumatoid disease. Noticeable improvement in clinical and laboratory parameters of disease activity has been observed by the third month of auranofin therapy. Further benefit occurs in some patients during the remainder of the first year of treatment. In the more than 3,000 patients treated with auranofin, the most frequently reported side effects were gastrointestinal (mainly diarrhea) and mucocutaneous. Most side effects were mild in nature and the withdrawal rate due to all adverse reactions averaged 11%. Auranofin differs from injectable gold by producing more gastrointestinal but fewer mucocutaneous reactions. The severity of these reactions is less with auranofin and causes fewer withdrawals from therapy.