Choosing the right ingredient for your Iron Infusion

At Effect Doctors, we use ferric derisomaltose (Monofer®) for all of our iron infusions. This decision is based on emerging evidence regarding the safety profile of different intravenous iron formulations, particularly their effects on phosphate levels.

Understanding Hypophosphataemia

Phosphate is an essential mineral involved in energy production, muscle function, bone health, and cellular repair. Low phosphate levels, known as hypophosphataemia, can cause symptoms including:

Fatigue
Muscle weakness
Bone pain
Difficulty concentrating
In severe cases, fractures and osteomalacia (softening of the bones)

Although many cases are mild and temporary, some patients develop significant or prolonged phosphate depletion after intravenous iron treatment.

What Does the Research Show?

A landmark randomised clinical trial published in JAMA by Wolf and colleagues compared two commonly used intravenous iron preparations: ferric carboxymaltose and ferric derisomaltose.

The study found that patients receiving ferric carboxymaltose were substantially more likely to develop hypophosphataemia than those receiving ferric derisomaltose. The difference was not small—it was one of the most striking safety findings reported in the intravenous iron literature.

Researchers demonstrated that ferric carboxymaltose can increase levels of a hormone called fibroblast growth factor 23 (FGF23). Elevated FGF23 causes the kidneys to excrete phosphate, leading to a drop in blood phosphate levels. Ferric derisomaltose had a much smaller effect on this pathway and was associated with significantly lower rates of hypophosphataemia.

Why This Matters to Patients

Most patients seeking iron infusions are already experiencing symptoms such as fatigue and reduced energy levels. We believe it is important to avoid treatments that may increase the risk of developing another cause of fatigue shortly after treatment.

While all intravenous iron products are effective at replacing iron, they are not identical. The available evidence suggests that ferric derisomaltose offers the benefits of rapid iron replacement while minimising the risk of clinically significant hypophosphataemia.

Our Approach at Effect Doctors

When selecting treatments, we consider both effectiveness and safety.

Ferric derisomaltose allows us to:

Deliver large iron doses in a single visit
Rapidly replenish iron stores
Reduce the risk of treatment-related hypophosphataemia
Provide a well-established and evidence-based treatment option

For these reasons, ferric derisomaltose is the intravenous iron preparation we have chosen to use routinely in our clinics.

The Bottom Line

Intravenous iron can be transformative for patients with iron deficiency, but the choice of iron formulation matters. High-quality clinical evidence has shown that ferric derisomaltose is associated with a substantially lower risk of hypophosphataemia compared with ferric carboxymaltose.

By using ferric derisomaltose as our standard iron infusion treatment, we aim to provide effective iron replacement while prioritising patient safety and long-term wellbeing.

Understand more about iron deficiency, our tests and our treatments here.

Reference

Wolf M, Rubin J, Achebe M, et al. Effects of Ferric Carboxymaltose vs Ferric Derisomaltose on Phosphate Homeostasis in Iron Deficiency Anemia: A Randomized Clinical Trial. JAMA. 2020;323(5):432–443.