Iron-chelating therapy.

Because of the catalytic action of iron in one-electron redox reactions, it has a key role in the formation of harmful oxygen derivatives and production of peroxidative damage to vital cellular structures. The clinical manifestations of iron overload may be prevented and even reversed by the effective administration of the iron-chelating drug deferoxamine (DF). Recent experimental evidence suggests that DF may also be useful in modifying disease conditions unrelated to iron overload by preventing the formation of free radicals, the powerful final effectors of tissue damage resulting from the respiratory burst of granulocytes and macrophages participating in the inflammatory response. Although much experimental work is still needed, this novel approach in iron-chelating therapy may have far-reaching implications in the management of autoimmune disease, adult respiratory distress syndrome, and organ transplantation. The poor intestinal absorption of DF, its almost prohibitive price, and short duration of action underline the need for new, orally effective iron chelators. A number of very promising orally effective drugs have been identified in recent years, such as the polyanionic amines, aryl hydrazones, and hydroxypyridones. Further development for clinical use of this new generation of iron-chelating drugs is a major challenge for future research.