Cuprimine is an anti-rheumatic drug that treats patients who have active rheumatoid arthritis that other drugs have not cured, Wilson's disease, and cystinuria. Also called a Disease Modifying Anti-Rheumatic Drug or DMARD, Cuprimine appears to slow down the progress of the disease, such as the deformities of the joints. Though it is not known how the drug acts on rheumatoid arthritis, its functions are suspected to be related to the reduction of the formation of collagen, the tissue compound from which formation results as a scar tissue from inflammation. Cuprimine may also suppress the immune system. The drug has an agent that is metal binding or chelating which treats a disease caused by genetics that excessively accumulates copper in the body, called Wilson's disease. Cuprimine binds mercury, cysteine, iron and copper excreted in the urine, a vital mechanism to treat several diseases which are non-rheumatic.