Pharmacology Notes

Desferrioxamine is an iron chelator that has high affinity for free ferric ion in the plasma. The complex formed is highly stable and water-soluble and is readily excreted in the urine. Desferrioxamine is also able to remove iron bound to transferrin and haemosiderin within the intravascular compartment.

Desferrioxamine is indicated for any patient with established iron toxicity or at risk of developing such toxicity. Desferrioxamine should not be withheld in pregnant patients who meet the criteria for treatment. It has no proven teratogenic effects during pregnancy (ADEC Category B3, . Fetal loss may occur as a result of severe maternal iron toxicity. The total iron binding capacity or the 'chelation challenge' test should not be used to determine the need for desferrioxamine.

In the setting of acute iron poisoning, desferrioxamine is administered via a continuous infusion. In such situations the intramuscular route of administration is unreliable.

Infusion-related hypotension is common. Patients should be adequately hydrated before commencing desferrioxamine. Histamine release may cause hypotension, flushing and urticaria. Desferrioxamine chelated to iron generally turns the urine orange-red.

Due to the potential risk of acute respiratory distress syndrome and respiratory toxicity, desferrioxamine should only be continued beyond 24 hours in exceptional situations. Cases of such toxicity are, however, confounded by the fact that these complications have occurred in cases of severe iron poisoning even in untreated cases.

Desferrioxamine interferes with many routine assays used to determine serum iron concentrations.