5. Contraindication to ferumoxytol (previous allergic drug reaction, any immune or inflammatory conditions (eg, systemic lupus erythematosus, rheumatoid arthritis, history of severe asthma, eczema or other atopic allergy)), evidence of known iron overload, hemochromatosis, known hypersensitivity to ferumoxytol or its components or anaemia not caused by iron deficiency.