Hypersensitivity

The FDA has
Feraheme (ferumoxytol) may cause serious hypersensitivity reactions, including anaphylaxis and/or anaphylactoid reactions. Serious hypersensitivity reactions were reported in 0.2% (3/1,726) of subjects administered Feraheme. Some other reactions potentially associated with hypersensitivity (e.g., pruritus, rash, urticaria or wheezing) were reported in 3.7% (63/1,726) of these subjects. It is necessary to monitor patients for signs and symptoms of hypersensitivity for at least 30 minutes following Feraheme injection and limit administration of the drug only to when personnel and therapies are readily available for the treatment of hypersensitivity reactions ^{FDA label}.

Ferumoxytol was not tested for carcinogenic effects. In general genotoxicity tests, ferumoxytol showed no evidence of mutagenic activity in an in vitro Ames test or clastogenic activity in either an in vitro chromosomal aberration assay or an in vivo micronucleus assay. No adverse effects on fertility were observed in animal studies. Ferumoxytol had no effect on male or female fertility or general reproductive function in rats ^{FDA label}.

Hypotension

Feraheme may cause significant hypotension.
In a clinical study with Feraheme in patients with IDA, regardless of etiology, moderate hypotension was reported in 0.2% of subjects receiving Feraheme administered as intravenous infusion for at least 15 minutes ^{FDA label}.

Iron overload

Excessive therapy with parenteral iron may lead to excess storage of iron with a possibility of iatrogenic hemosiderosis. Frequently monitor the hematologic response during parenteral iron therapy. It is advised not to administer Feraheme to patients with iron overload ^{FDA label}.

A note on MRI studies

Administration of Feraheme may transiently affect the diagnostic ability of MR imaging. Anticipated MR imaging studies should be done before the administration of Feraheme. Alteration of MRI imaging studies may persist for up to 12 weeks after the last Feraheme dose ^{FDA label}.