Gold salts, adverse effects

With the combination of traditional DMARDs complete remissions are obtained in 30% of early RA over a period of 5 years. These remissions last on average less than 10 months. After 5 years only half of the patients continue with MTX and less than 25% stay on other DMARDs. After 5 years non-compliance is mostly due to adverse effects and lack of efficacy of NSAIDs, hydroxychloroquine, sulfasalazine, prednisone, d-penicillamine, azafhio-prine, and gold salts. Only MTX retains some efficacy. With these therapeutic modalities joint erosions progress to permanent joint destruction, deformities and disability. 

In rheumatoid arthritis the most commonly used gold salts are sodium aurothiomalate and aurothioglucose (3). There is some reason to believe that adverse effects are less frequent with the suspensions (of aurothioglucose or aurothiosulfate) than with the more rapidly absorbed solution (of sodium gold thiomalate) (SEDA-16, 233) (4). 

Adverse effects of gold salts occur in about one-third of systemically treated patients, the incidence varying from 25 to 40%. The dropout rate due to adverse reactions has been assessed as 22-26% (9). Children are considered to show the same pattern of adverse reactions as adults. 

Apart from the nitritoid cardiovascular reaction, which is unique to sodium aurothiomalate, and possible differences between slowly and rapidly absorbed gold salts in the relative frequency of adverse effects, the general pattern of adverse reactions is similar for all parenteral gold salts. 

Monovalent gold salts impacted metabolism of seleifium, copper, and zinc. Intravenous Au" " may adversely affect the availability of seleifium for synthesis of selenoenzymes. Rats given gold sodium thiomalate iv at 25.0 or 50.0 xmol/kg BW had sigifificantly altered seleifium deposition, as measured by radioselenium-75. These effects included the almost complete cessation of Se exhalation as dimethyl sulfide and the accumulation of Se in blood plasma. Direct chemical reaction with nucleophilic selenium metabolites in the body may underlie these alterations. Auranofin inhibited selenium-glutathione peroxidase in bovine erythrocytes this enzyme... 

It may be noted that many toxic metals are also essential for the body, at trace levels. Their absence from the diet can produce various deficiency syndromes and adverse health effects. Such essential metals include selenium, copper, cobalt, zinc, and iron. On the other hand, excessive intake can produce serious adverse reactions. Also, a number of metals, such as aluminum, bismuth, lithium, gold, platinum, and thallium, have been used in medicine. Despite their beneficial effects, excessive intake of these metals and their salts can cause serious poisoning. 

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