Effects of iron isomaltoside vs ferric carboxymaltose on hypophosphatemia in iron-deficiency anemia: two randomized clinical trials.

This article describes a new physiology via the upregulation of FGF23 by ferric carboxymaltose (FCM) with subsequent development of hypophosphatemia.  It provides a degree of caution with the long-term use of this formulation of IV iron but aptly points out that clinically significant hypophosphatemia is rare. 

What this should do is stimulate long-term evaluation of the safety of this widely used product. The paper also appropriately points out the need to monitor phosphorus levels as a routine part of FCM’s use.

The physiology is beautifully described and the reader will know much more about renal physiology after reading the manuscript. 

– Michael Auerbach