Serum iron determination in patients receiving therapy with iron dextran ("Imferon")

Imferon (Lakeside Labs., Inc.), an iron dextran complex, is widely used for parenteral therapy with iron. Colorimetry and atomic absorption spectroscopy give different values for serum iron concentration in patients receiving such therapy. Values determined by atomic absorption spectroscopy were usually much higher than those obtained by either a manual or an automated colorimetric procedure, and also were higher than the total serum iron-binding capacity of the same sera. This difference is attributed to circulating iron being present both as iron dextran as as transferrin-bound iron. We conclude that atomic absorption spectroscopy should be used to determine serum iron in patients receiving Imferon.