Does intravenous (IV) iron dextrose decrease International Normalized Ratio (INR)?

Does IV Iron Dextrose Decrease INR?

No, there is no evidence in the medical literature that intravenous (IV) iron dextran decreases International Normalized Ratio (INR). The available guidelines and research do not indicate any effect of IV iron preparations on coagulation parameters such as INR.

IV Iron Formulations and Their Effects

• IV iron preparations come in several formulations including iron dextran (INFeD and Dexferrum), ferric sodium gluconate (Ferrlecit), iron sucrose (Venofer), ferric carboxymaltose, and ferumoxytol 1
• These formulations differ in their complex chemistry, dosing, and safety profiles, but none are documented to affect coagulation parameters or INR 2, 3
• Modern IV iron formulations are composite nanoparticles composed of carbohydrate ferric oxy-hydroxides designed primarily to treat iron deficiency anemia 3

Clinical Considerations When Using IV Iron

Safety Profile and Adverse Effects

• The primary concerns with IV iron administration are:

  • Idiosyncratic reactions (anaphylactic-like reactions, hypotension) that are not dose-related 1
  • Dose-related adverse effects such as arthralgias and myalgias, particularly with higher doses 1
  • Life-threatening/serious acute reactions to IV iron dextran reported in approximately 0.65-0.7% of patients 1

• Notable adverse effects do NOT include alterations in coagulation parameters:

  • Delayed reactions characterized by arthralgias and myalgias are dose-related and rarely occur with doses of 100 mg or less 1
  • Ferric sodium gluconate may rarely be associated with hypotension, flushing, loin pain and gastric pain 1
  • Newer formulations may cause hypophosphatemia in some cases 3

Dosing and Administration

• For hemodialysis patients, small frequent doses (100 mg) are recommended to minimize dose-related adverse effects 1
• For CKD, home hemodialysis, or PD patients, larger single doses (500-1000 mg) may be administered but with increased risk of myalgias/arthralgias 1
• Pediatric dosing should be weight-adjusted according to established guidelines 1

Clinical Implications

• When monitoring patients on IV iron therapy, clinicians should focus on:

  • Hemoglobin levels and iron parameters (ferritin, transferrin saturation) 1
  • Potential adverse reactions during and after infusion 1
  • There is no recommendation to monitor INR or other coagulation parameters specifically due to IV iron administration 1

• The goal of IV iron supplementation is to:

  • Normalize hemoglobin levels and iron stores 1
  • Support erythropoiesis, especially in patients receiving erythropoiesis-stimulating agents 1
  • Improve quality of life and reduce morbidity associated with anemia 3

Pitfalls and Caveats

• Do not confuse spuriously high transferrin saturation levels that may occur shortly after IV iron administration with effects on coagulation parameters 1
• Test doses may be advisable for low-molecular-weight iron dextran but are no longer mandatory 1
• Patients who have shown severe reactions to one iron dextran preparation should not be administered another due to potential cross-reactivity 1
• When administering IV iron, be prepared to manage potential hypersensitivity reactions rather than monitoring for coagulation changes 2, 4