Therapeutic uses of trace elements.

The properties of trace elements which feature in their therapeutic activity are: binding to macromolecules (enzymes, nucleic acids, etc.) with disturbance of biological function, and interaction with other elements. These properties, particularly the binding to large molecules, are far from specific, an observation which is reflected in the very wide range of diseases in which trace elements are employed. While metal compounds have been administered for several centuries, the scientific basis for treatment with trace elements began with the use of gold compounds, initially in patients with tuberculosis and later those with rheumatoid arthritis. Although many other drugs have been developed, some of which also include metal complexes, gold has retained an important position in the treatment of this condition. The gold-induced effects upon the immunological aspects of RA are also observed in other conditions with autoimmune involvement. The antineoplastic potential of metal complexes will be further exploited by the development of less toxic compounds--of platinum and possibly also of other metals. At the same time there are improvements in the protocols for administration which increase the range of cancers responding to treatment. Perturbation of gastrointestinal activity represents another area where trace elements have an important therapeutic role, both in the control of intraluminal acidity and in the adjustment of nutrient availability. A fourth significant area of trace element therapeutics involves the central nervous system where the use of lithium has provided spectacular results in the treatment of affective and other disorders. With a very wide range of other conditions in which they are employed, therapeutic uses provide somewhat unusual illustrations of the importance of trace elements in human disease.