A steady decline in gold levels occurs when the interval between injections is lengthened, and small amounts may be found in the serum for months after discontinuance of therapy. The incidence of toxic reactions is apparently unrelated to the plasma level of gold, but it may be related to the cumulative body content of gold. Storage of gold in human tissues is dependent upon organ mass as well as upon the concentration of gold. The highest concentrations of gold are found in the lymph nodes, adrenal glands, liver, kidneys, bone marrow, and spleen. Relatively small concentrations are found in articular structures.
Gold passes the blood-brain barrier in hamsters.
Transfer of gold across the human placenta at the 20th week of pregnancy has been documented. In chronic, advanced cases of rheumatoid arthritis, gold therapy is less valuable. After improvement commences, these measures may be discontinued slowly as symptoms permit. See Precautions, Laboratory Tests and Dosage. A history of known hypersensitivity to any component of aurothioglucose contraindicates its use.