The Food and Drug Administration has added a boxed warning, its most prominent safety label, to a widely used intravenous iron drug after concluding that patients continue to develop dangerously low blood phosphate levels and that the monitoring meant to catch the problem is rarely being done.
The drug is ferric carboxymaltose injection, marketed as Injectafer and approved by federal drug regulators in 2013. It treats iron deficiency anemia in patients aged one year and older who cannot tolerate or do not fully respond to iron taken by mouth. It is also approved for iron deficiency in adults with non-dialysis-dependent chronic kidney disease and in adults with New York Heart Association class II or III heart failure to improve exercise capacity.
