Ferric carboxymaltose-induced hypophosphatemia - a case series

Hypophosphatemia may cause serious complications. Depending on its severity and duration, signs and symptoms range from fatigue to life-threatening events, like severe rhabdomyolysis and mental status changes. Long-term consequences include osteomalacia. Hypophosphatemia may be secondary to the use of parental iron, mostly associated with ferric carboxymaltose (FCM), with an incidence of around 45% to 70%. We describe three cases of hypophosphatemia in patients with chronic iron deficiency anemia, requiring repeated FCM infusions. The patients' presentation to the Rheumatology department included musculoskeletal symptoms of severe hypophosphatemia and long-term hypophosphatemic osteomalacia, with fractures. We aim to raise awareness for ferric carboxymaltose-induced hypophosphatemia, an entity increasingly described in the literature that can be responsible for severe disability or potentially life-threatening adverse events.