Iron is a vital component of the human body, and its concentration is strictly regulated. While iron is essential for life, it can also be toxic to the cells. Iron overload is associated with multiorgan damage. This is due to a lack of ways to protect human cells from iron overload and iron function in the production of free radicals. Iron overload occurs when iron intake is increased over time, whether as a result of red blood cell transfusions, increased iron absorption through the gastrointestinal tract, repeated transfusions, iron misuse often as a supplement, chronic hepatitis, or hereditary hemochromatosis.

Iron chelators are used to treat iron overload in various clinical conditions. The three United States Food and Drug Administration-approved iron chelators are deferoxamine, deferiprone, and deferasirox.

Different types of Iron Chelators

1. DEFEROXAMINE (DFO)

DFO is the earliest iron chelator used clinically. It can combine with ferric ions to form a ferric amine complex. Continuous high-dose infusion of DFO can significantly reduce the cardiotoxicity caused by iron overload, improve ventricular function relatively quickly, reduce iron overload-related complications, and improve the overall survival rate and quality of life of patients. However, DFO cannot remove iron ions from transferrin, hemoglobin, or other heme-containing substances, and cannot effectively remove intracellular iron.

2. DEFERIPRONE (DFP)

DFP is the first iron-chelating agent to be taken orally after deferoxamine is used clinically. Both in vivo and in vitro studies have shown that DFP can remove intracellular iron, reticuloendothelial iron, transferrin-bound iron, and iron stored in the form of ferritin and hemosiderin. A number of prospective and retrospective studies have proved that DFP is significantly better than DFO in the treatment of cardiac iron overload in patients with thalassemia major.

3. DEFERASIROX (DFS)

DFS is the latest oral iron-removing agent on the market. It is recommended in the United States and Europe as the first-line drug for patients with iron overload in thalassemia over 6 years old. DFS can remove non-transferrin-bound free iron in plasma, iron in reticuloendothelial cells, and parenchymal organ cells, and can also prevent cardiomyocytes from taking up iron and remove excess iron directly from cardiomyocytes.

Overall, DFO, DFP, and DFS are all effective chelators for the treatment of iron overload. However, each agent has its own unique side effect profile and is suitable for different indications. DFO is particularly useful in the treatment of hemochromatosis, while DFP is indicated for the treatment of iron-deficiency anemia. DFS is a promising new oral chelator that is effective in the treatment of hemochromatosis and iron-deficiency anemia. Despite their differences, all three agents are safe and well-tolerated in the majority of patients.