Interaction between ferric carboxymaltose and denosumab causing severe hypocalcaemia and hypophosphataemia in a patient without chronic kidney disease.

Coadministration of ferric carboxymaltose and denosumab may cause hypocalcaemia and hypophosphataemia; however, this interaction is not well-described in the literature and has typically been described in patients with chronic kidney disease (CKD). We present a case of this interaction in a patient without preexisting CKD. We suggest the use of alternative iron preparations and an interval of at least 4 weeks between administrations.