Therapy with either
deferiprone (
DFP) or
deferoxamine (DFO) is inadequate in achieving negative
iron balance in many patients with
thalassemia. There are mounting theoretical, experimental, and clinical evidences of increased efficacy when
therapy includes both
chelating agents.
DFP and DFO chelate excess
iron in different ways without affecting each other's metabolism. When both
chelators are administered simultaneously, they interact either in an additive or synergistic manner, probably through "shuttling"
iron from
DFP to DFO.
Iron-balance studies have shown that the use of both agents on the same day can induce negative
iron balance in all patients. Long-term combined
therapy with DFO with
DFP results in considerable reduction of both
ferritin levels and liver
iron concentration as well as significant improvement in cardiac
siderosis and function. This therapeutic regimen is well tolerated and safe, even though it may be related to a small increase in the incidence of
agranulocytosis compared with
DFP monotherapy. Apart from using both agents simultaneously, sequential administration of
DFP and DFO has also shown promising results. Combining the available
iron chelators offers many therapeutic options that can be tailored to each patient individually. It is an exciting advance in treating
hemosiderosis in thalassemic patients.