Gold-containing drugs arepharmaceuticals that containgold. Sometimes these species are referred to as "gold salts". "Chrysotherapy" and "aurotherapy" are the applications of gold compounds to medicine.[1] Research on the medicinal effects of gold began in 1935,[2] primarily to reduceinflammation and to slowdisease progression in patients withrheumatoid arthritis. The use of gold compounds has decreased since the 1980s because of numerous side effects and monitoring requirements, limited efficacy, and very slow onset of action. Most chemical compounds of gold, including some of the drugs discussed below, are not salts, but are examples ofmetal thiolate complexes.
Investigation of medical applications of gold began at the end of the 19th century, whengold cyanide demonstrated efficacy in treatingMycobacterium tuberculosis in vitro.[3]
The use of injected gold compound is indicated for rheumatoid arthritis.[4] Its uses have diminished with the advent of newer compounds such as methotrexate and because of numerous side effects.[4] The efficacy of orally administered gold is more limited than injecting the gold compounds.[5]
The mechanism by which gold drugs affect arthritis is unknown.[5]
Gold-containing drugs for rheumatoid arthritis are administered by intramuscular injection but can also be administered orally (although the efficacy is low). Regular urine tests to check forprotein, indicatingkidney damage, andblood tests are required.
A 1997 review (Suarez-Almazor ME,et al)[6] reports that treatment with intramuscular gold (parenteral gold) reduces disease activity and joint inflammation. Gold-containing drugs taken by mouth are less effective than by injection. Three to six months are often required before gold treatment noticeably improves symptoms.
A noticeable side-effect of gold-based therapy is skin discoloration, in shades of mauve to a purplish dark grey when exposed to sunlight. Skin discoloration occurs when gold salts are taken on a regular basis over a long period of time.[7] Excessive intake of gold salts while undergoing chrysotherapy results – through complex redox processes – in the saturation by relatively stable gold compounds of skin tissue and organs (as well as teeth and ocular tissue in extreme cases) in a condition known aschrysiasis. This condition is similar toargyria, which is caused by exposure to silver salts and colloidal silver.Chrysiasis can ultimately lead toacute kidney injury (such as tubular necrosis, nephrosis, glomerulitis),[8] severe heart conditions, and hematologic complications (leukopenia, anemia).[9][10][11] While some effects can be healed with moderate success, the skin discoloration is considered permanent.
Other side effects of gold-containing drugs include kidney damage, itching rash, and ulcerations of the mouth, tongue, and pharynx. Approximately 35% of patients discontinue the use of gold salts because of these side effects. Kidney function must be monitored continuously while taking gold compounds.[5]
adverse effects including allergy to gold, tolerance to gold decreasing with age, skin and renal complications.