DEFEROXAMINE MESYLATE

Chemistry - An iron chelating agent, deferoxamine mesylate occurs as a white to off-white powderthat is freely soluble in alcohol or water. Deferoxamine may also be known as desferoxaminemesylate or by the abbreviation DFO.

Storage, Stability, Compatibility

Store at room temperature. After reconstitution with sterilewater for injection, the solution may be stored at room temperature, protected from light for up toone week. It is recommended not to mix this agent with other drugs; do not use if solution is turbid.
Dilution in either normal saline, lactated Ringer's or dextrose 5% has been recommended whenadministering as an intravenous infusion.

Pharmacology - DEFEROXAMINE MESYLATE

Deferoxamine (DFO) binds ferric (Fe+++) ions to its three hydroxamic groupsforming ferrioxamine. This forms a stable, water soluble compound that is readily excreted by thekidneys. DFO does not appear to chelate other trace metals (except aluminum) or electrolytes inclinically significant quantities.
Uses, Indications - Deferoxamine is used for the treatment of either acute or chronic iron toxicity.
It is being evaluated as an iron chelator for adjunctive treatment of acute cardiac ischemia and as achelator for aluminum toxicity.

Pharmacokinetics - DEFEROXAMINE MESYLATE

DFO is poorly absorbed from the GI and is usually given parenterally. Thedrug is widely distributed in the body. DFO and ferrioxamine are excreted primarily in the urine.
Ferrioxamine will give the urine a reddish color ("vin ros") which indicates iron removal.

Contraindications, Precautions, Reproductive Safety

DFO is contraindicated in patients withsevere renal failure, unless dialysis is used to remove ferrioxamine.
Because deferoxamine has caused skeletal abnormalities in animals at dosages just above thoserecommended for iron toxicity, it should be used during pregnancy only when its benefits outweighit risks.

Adverse Effects, Warnings

There is little veterinary experience with this drug. Potential adverseeffects include, allergic reactions, auditory neurotoxicity (particularly with chronic, high-dosetherapy), pain or swelling at injection sites, and GI distress. Too rapid IV injection may cause rapidheart rates, convulsions, hypotension, hives, and wheezing.
Oral administration of DFO is controversial. Some have recommended oral administration afteroral iron ingestions, but DFO may actually increase the amount of iron absorbed from the gut. Atpresent, oral sodium bicarbonate solution 5% given as a gastric lavage is probably a better treatmentin reducing oral absorption of iron.

Overdosage, Acute Toxicity

See above adverse effects. Chronic high dose use may also lead tohypocalcemia and thrombocytopenia.

Drug Interactions

Vitamin C may be synergistic with deferoxamine in removing iron, but mayin fact, lead to increased tissue iron toxicity especially in cardiac muscle. It should be used withcaution, particularly in patients with preexisting cardiac disease.
Laboratory Considerations - DFO may interfere (falsely low values) with colorimetric ironassays. It may also cause falsely high total iron binding capacity (TIBC) measurements.