Can IV (intravenous) ferric carboxymaltose (iron) and oral iron be given simultaneously?

Simultaneous Administration of IV Ferric Carboxymaltose and Oral Iron

IV ferric carboxymaltose and oral iron should not be administered simultaneously as there is no clinical benefit to this combination and it may reduce the efficacy of the IV iron preparation while increasing the risk of adverse effects. 1

Rationale for Not Combining IV and Oral Iron

• When IV iron is administered, it rapidly increases serum iron, ferritin, and transferrin saturation, making concurrent oral iron supplementation redundant 1
• Oral iron absorption is regulated by hepcidin, which increases after IV iron administration, thereby blocking intestinal iron absorption and rendering oral iron ineffective 1
• Oral iron is associated with significant gastrointestinal side effects in up to 60% of patients (constipation, diarrhea, nausea), which would unnecessarily add to the potential side effect burden 1
• IV iron preparations like ferric carboxymaltose are designed to deliver controlled amounts of iron to target tissues, and this careful dosing could be disrupted by simultaneous oral iron intake 2

Appropriate Iron Therapy Selection

For Absolute Iron Deficiency (TSAT <20% and Ferritin <30 ng/mL):

• IV iron (preferred) or oral iron monotherapy is recommended 1
• These therapies should not be combined simultaneously 1

For Functional Iron Deficiency (TSAT 20-50% or Ferritin 30-800 ng/mL):

• IV iron alone or IV iron with erythropoiesis-stimulating agents (ESAs) is recommended 1
• Oral iron is not effective for functional iron deficiency 1

Administration Considerations for IV Iron

• Ferric carboxymaltose can be administered as a single high dose (up to 1000 mg) over 15 minutes 1, 2
• Patients should be observed for at least 30 minutes following IV iron administration to monitor for hypersensitivity reactions 1
• IV iron should not be administered during periods of neutropenia due to increased risk of infection (RR 1.33) 1
• IV iron should not be administered on the same day as anthracyclines due to theoretical risk of potentiating cardiotoxicity 1

Monitoring After Iron Therapy

• Iron status should be re-evaluated approximately 3 months after IV iron administration 1
• Do not check iron parameters too early after IV iron infusion as ferritin levels will be falsely elevated 1
• Success of treatment is measured by improvement in hemoglobin levels and replenishment of iron stores 2

Common Pitfalls to Avoid

• Administering IV iron during active infection (contraindicated) 1
• Giving iron to patients with iron overload or disturbances in iron utilization 1
• Using high-molecular weight iron dextran (Dexferrum), which has higher risk of anaphylactic reactions compared to other iron formulations including ferric carboxymaltose 1
• Administering IV iron too rapidly, which increases risk of hypersensitivity reactions 3

In summary, while both IV ferric carboxymaltose and oral iron have their place in treating iron deficiency anemia, they should be used sequentially rather than simultaneously based on the patient's iron status and clinical condition 1.