FDA Warning on Ferumoxytol

The US Food and Drug Administration (FDA) issued a strong warning on a drug used to treat iron deficiency anemia in patients with chronic kidney disease.

Injections of ferumoxytol (Feraheme/Amag Pharmaceuticals) can cause serious allergic reactions including death in patients who are sensitive to the drug, the FDA warned in a new boxed warning. The drug was approved in 2009 and there were no such problems reported in clinical trials.

Now the FDA says the drug should only be given when physicians are immediately available to treat anaphylaxis and other hypersensitivity reactions.

Physicians are advised to watch for those reactions for 30 minutes after giving the injection by IV infusion. That includes monitoring blood pressure and pulse.

The warning is based on post-marketing reports which have included “fatal, life-threatening, and serious anaphylactic-type reactions, cardiac/cardiorespiratory arrest, clinically significant hypotension syncope, unresponsiveness, loss of consciousness, tachycardia, angioedema, ischemic myocardial events, congestive heart failure, pulse absent and cyanosis,” the FDA reported in announcing the new warning.

The reactions have occurred both after a first dose of the drug, or later in patients who had no reaction the first time they got the injection. A full list of precautions is here.

In clinical trials there were milder adverse reactions, with about 3% of subjects reporting nausea.

Feraheme is a superparamagnetic iron oxide coated with a carbohydrate shell that isolates bioactive iron from plasma compoents until the iron-carbohydrate complex enters the reticuloendothelial system macrophages of the liver, spleen and bone marrow. The iron is released within vesicles in the macrophages and then is either sored incide cells or is transferred to plasma transferrin for transport to erythroid precursor cells for incorporation into hemoglobin.