Iron chelation

Adequate iron chelation in thalassaemia has resulted in a striking improvement in survival, with a reduction of cardiac mortality at age 15 years from 14-3%, and a predicted survival at age 36 years of 85%. Long term desferrioxamine (DF) therapy in thalassaemic children should be started between 2-4 years of age. In addition to daily 8-12 h subcutaneous infusions, intermittent high dose (9-16 g) i.v. supplementation over 24-48 h may be given on the occasion of blood transfusions. In established myocardiopathy continuous i.v. DF infusion at 100-125 mg/kg/d may result in improved myocardial function. In addition, there is considerable current interest in the use of DF in conditions unrelated to iron overload by preventing the formation of free-radicals in inflammatory reactions, or by S-phase inhibition of cell proliferation. Although at present highly experimental, this novel approach may have important implications for the management of patients with inflammatory conditions and perhaps in the control of protozoal infections. Over the last decade several hundred candidate compounds have been studied in cell cultures and in animal models and a number of orally effective iron chelators have been identified, all of which are superior to DF in their in vivo iron chelating effect. Although we do not yet have a new drug which is immediately available for replacing DF in clinical practice, significant progress has already been made, and some of the most promising candidate drugs are currently undergoing extensive toxicity tests in anticipation of their development for large-scale clinical use.