Medication Summary
The goals of pharmacotherapy are to reduce iron levels, prevent complications, and reduce morbidity. Deferoxamine (Desferal) is used for chelation of iron in both acute and chronic toxicity.
The oral chelating agent deferasirox (Exjade) is approved by the US Food and Drug Administration (FDA) for the treatment of chronic iron overload due to blood transfusions in patients 2 year of age and older; it is also approved for treatment of chronic iron overload resulting from non–transfusion-dependent thalassemia.
Chelation agents
Class Summary
Deferoxamine is a specific iron chelator. In the presence of ferric iron, deferoxamine forms the complex ferrioxamine, which is excreted by the kidneys. This complex imparts a reddish, vin rosé, color to the urine. Deferoxamine does not bind iron that is present in hemoglobin, hemosiderin, or ferritin. Deferoxamine is a parenteral iron chelator. It is administered IV or IM in the management of acute iron toxicity.
Deferoxamine mesylate (Desferal)
Freely soluble in water. Approximately 8 mg of iron is bound by 100 mg of deferoxamine. Most effective when continuously provided to the circulation by infusion. May be administered either by IM injection or by slow IV infusion. Does not effectively chelate other trace metals of nutritional importance. Provided in vials containing 500 mg or 2 g of lyophilized sterile drug. Add 2 mL or 8 mL of sterile water for injection to each vial, bringing the concentration to 250 mg/mL. For IV use, this may be diluted in 0.9% sterile saline, 5% dextrose solution, or Ringer solution.
Deferasirox (Exjade)
Tab for PO susp. PO iron chelation agent demonstrated to reduce liver iron concentration in adults and children who receive repeated RBC transfusions. Binds iron with high affinity in a 2:1 ratio. Approved to treat chronic iron overload due to multiple blood transfusions. Treatment initiation recommended upon evidence of chronic iron overload (ie, transfusion of about 100 mL/kg packed RBCs [about 20 U for 40-kg person] and serum ferritin level consistently >1000 µg/L).
Whole bowel irrigation agents
Class Summary
Polyethylene glycol is used to increase GI transit time, decreasing absorption. It is not absorbed and is excreted entirely through the GI tract.
Polyethylene glycol (GoLYTELY, NuLytely, Colovage, Colyte)
Laxative with strong electrolyte and osmotic effects that has cathartic actions in GI tract.
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The oxidative potential of iron was first proposed by Fenton in 1894. The importance of reduced oxygen species in biological reactions became apparent with the discovery of superoxide dismutase by McCord and Fridovich in 1969. The potential role of metal ion catalysis was reported the following year. Subsequently, a plethora of evidence has accumulated linking chronic excess body iron to cardiovascular disease, carcinogenesis, aging, stroke, Alzheimer disease, and Parkinson disease. The organ damage that occurs in the hereditary iron overloading disorders is well documented and can be averted and improved by decreasing the excess iron. Acute iron overload likewise produces tissue and organ damage due to the presence of free ionic iron.
