[Safety of parenteral iron therapy]

Intravenous iron supplementation is generally required to optimize the action of agents stimulating erythropoiesis. All parenterally administrated iron preparations raise risk of acute or chronic side effects related to allergic reactions, cell toxicity, or endothelial dysfunction. Each product proposed has specific structural and biochemical characteristics explaining its specific pharmacological and biochemical properties. None of the available products contains free iron but all contain a small fraction of biologically active labile iron. The anaphylactoid reactions initially described after administration of high-molecular-weight iron dextran are rare with iron sucrose. In clinical practice, the problem is generally iron deficiency, iron overload generally not being a serious problem. The contribution of biologically active iron to increased oxidative stress in the dialysis patient is an important issue for debate. The cardiovascular risk of iron was pointed out by evidence from experimental studies but the epidemiological data have been contradictory, both in dialysis patients and in the general population, and are insufficient to confirm an increased cardiovascular risk in dialysis patients when the serum ferritin level is maintained within the recommended range. The risk of infection is related to the effect of iron on bacterial virulence and on the organism's defense mechanism against bacterial infection. An analysis of the clinical evidence obtained in dialysis patients suggests that the role iron i.v. might play in increased bacterial risk would require, if it truly exists, doses so high the real effect would be marginal compared with identified major risk factors.