FDA Adds Boxed Warning to Ferric Carboxymaltose (Injectafer) for Risk of Serious Hypophosphatemia

The FDA has added a boxed warning to the labeling for Injectafer (ferric carboxymaltose) to highlight the risk of serious symptomatic hypophosphatemia. This condition, characterized by low serum phosphate, can lead to hospitalization, prolonged phosphate replacement, osteomalacia, and fractures. Clinicians are advised to check serum phosphate levels before repeat treatment in at-risk patients and to correct pre-existing hypophosphatemia. Patients should be counseled to report symptoms such as new or worsening fatigue, muscle weakness, or bone pain.