Comparative Biochemical Effects of Ferric Carboxymaltose and Iron Sucrose: Focus on Hypophosphatemia and Calcium Homeostasis

Abstract

Objective: To assess the frequency and severity of hypophosphatemia that arises after treatment with ferric carboxymaltose and consequent hypocalcaemia, compared with iron sucrose, to better understand their safety implications in clinical practice.

Study Design: Comparative study
Place and Duration of Study: This study was conducted at the Al-Diwaniyah Teaching Hospital Diwaniyah, Iraq from 1st October 2024 to 31st May 2025.

Methods: Thirty patients diagnosed with iron deficiency anemia were enrolled. Half received ferric carboxymaltose, while the remaining 15 were treated with iron sucrose. Biochemical evaluations (serum phosphate and calcium) levels were performed before treatment and repeated two weeks after the final infusion to assess potential alterations associated with each therapy.

Results: In ferric carboxymaltose group, a notable decrease in serum phosphate levels and a mild reduction in calcium concentrations were observed, whereas the iron sucrose group maintained stable mineral profiles. These changes suggest that ferric carboxymaltose exerts distinct effects on mineral metabolism, potentially mediated by its
pharmacodynamic properties.

Conclusion: The differential impact of FCM and IS on phosphate and calcium homeostasis underscores the importance of individualizing intravenous iron therapy choices. For patients with pre-existing mineral imbalances or risks of hypophosphatemia, careful consideration of metabolic effects is essential to optimize safety and clinical outcomes.