Intravenous Iron (III) Hydroxide Polymaltose Complex Infusion Related Severe Prolonged Hypophosphatemia

Intravenous iron infusion-related hypophosphatemia is an increasingly recognized phenomenon, potentially underdiagnosed in clinical practice. This case report describes the first known instance to the best of our knowledge, of severe hypophosphatemia following iron (III) hydroxide polymaltose complex (IPC) infusion in a 60-year-old woman with multiple comorbidities. The patient, with a history of diabetes mellitus type 2, hyperlipidemia, stable stage 3 chronic kidney disease, iron deficiency anemia, and osteoporosis, was found to have severe asymptomatic hypophosphatemia (<0.1 mmol/dL) during a general workup. She exhibited mild chronic numbness of the hands and feet, restless leg syndrome, and muscular pain in her shoulders, though her clinical examination was unremarkable. The patient had received three IPC infusions over two months prior to presentation. She was admitted and treated with intravenous phosphate followed by oral sodium phosphate. The patient remained well and asymptomatic throughout the treatment.