Treatment of iron deficiency anemia: Are monomeric iron compounds suitablefor parenteral administration?

Iron deficiency is the most common nutritional problem worldwide, especiall y in the developing countries. Oral iron supplementation programs have fail ed because of noncompliance and gastrointestinal toxicity thereby necessita ting parenteral administration of iron. For parenteral administration, only iron-carbohydrate complexes are currently used, because monomeric iron sal ts release free iron, thereby causing oxidant injury. However, iron-carbohy drate complexes also have significant toxicity and they are expensive. We h ave proposed the hypothesis that monomeric iron salts can be safely adminis tered by the parenteral route if iron is tightly complexed to the ligand, t hereby causing clinically insignificant release of free iron, and the kinet ic properties of the compound allow rapid transfer of iron to plasma transf errin, A detailed analysis of the physicochemical and kinetic properties re veals that ferric iron complexed to pyrophosphate or acetohydroxamate anion s may be suitable for parenteral administration. We have demonstrated that infusion of ferric pyrophosphate into the circulation via the dialysate is safe and effective in maintaining iron balance in patients undergoing maint enance hemodialysis. Parenteral administration of monomeric iron compounds is a promising approach to the treatment of iron deficiency in the general population and merits further investigation.