Desferal Toxicity

There is only one safe and effective iron chelator available today: Desferal. Desferal (desferrioxamine) was isolated from a bacteria, Streptomyces pilosus, in the 1960's. Initially it was developed as an antibacterial agent, and later as a delivery vehicle for iron. Eventually, it was used as an iron chelator for children who had iron overload (hemosiderosis) from transfusion. It was not a particularly effective chelator until the introduction of small pumps to infuse the chelator over many hours.

Desferal can be used subcutaneously or intravenously to remove iron from children and adults who have hemosiderosis secondary to transfusions or ingestion. It is well documented that continuous use of this agent can produce a negative iron balance and is very effective in removing iron from the body. It is more effective is used with ascorbic acid (vitamin C). Vitamin C must be used only with Desferal in iron overloaded individuals, since larger doses without Desferal can cause an increase in free iron and increased toxicity, particularly cardiac toxicity.
An oral iron chelator (L-1 or deferiprone) has been studied and found to be less effective than Desferal. Recently, it has been shown to have severe side effects when used for many years. This drug has not been released by the Food and Drug Administration, and further testing is being done with this drug in the United States and around the world. This medication is used in countries where the potential side effects of hemosiderosis outweigh the dangers if L-1. There are numerous other chelators being developed, including a long-acting form of desferrioxamine.
Desferal itself has several side effects. The most common is irritation at the site of administration. Using more normal saline or sterile water to mix the Desferal makes it much less irritating. Usually Desferal is mixed as 500 mg/2 cc: a 25% solution; less irritating is a 12.5% solution. Occasionally, the needle is not in the subcutaneous space and blisters leading to scarring can occur. <page 2>