36 - Management of iron overload

Summary

Iron overload is characterized by excessive iron deposition in and consequent injury and dysfunction of target organs, especially the heart, liver, anterior pituitary, pancreas, and joints (Chapter 5). Because physiologic mechanisms to excrete iron are very limited, patients with iron overload and its complications need safe, effective therapy that is compatible with their co-existing medical conditions. Worldwide, prevention of death due to cardiac siderosis is the most important potential benefit of therapy. The incidence of cardiac complications is greatest in patients with beta-thalassemia major and other heritable anemias treated with multiple transfusions. The liver is the primary target organ of iron overload in hemochromatosis and African iron overload, although maintaining normal hepatic function is important in all patients with iron overload. Preventing injury to endocrine organs is critical in children with iron overload. Successful treatment or prevention of iron overload increases quality of life and survival in many patients.

Therapeutic phlebotomy removes iron as hemoglobin, and is thus suitable for treatment of patients with iron overload without severe anemia in whom erythropoiesis is fundamentally normal (Table 36.1). Many reports substantiate the effectiveness, outcomes, and safety of phlebotomy therapy in HFE hemochromatosis and allied disorders. Chelation therapy employs drugs that preferentially bind excess iron and increase its excretion (Table 36.1). Some dietary maneuvers may decrease the absorption of dietary iron, and may be useful as adjunctive therapy for some patients with iron overload, although such treatments do not diminish body iron burdens.