From the Guidelines
Iron infusions are indicated when the iron saturation percent is less than 20%. This recommendation is based on the guideline provided by the American Journal of Kidney Diseases, which states that if TSAT is < 20%, supplemental iron should be administered 1. The guideline also emphasizes the importance of maintaining TSAT > 20% to ensure adequate iron stores.
Key Considerations
- The decision to administer iron infusions should be individualized based on the patient's clinical condition, severity of anemia, and underlying cause of iron deficiency.
- Ferritin levels should also be considered, as there is insufficient evidence to recommend IV iron if ferritin > 500 ng/mL 1.
- Common iron infusion preparations include iron sucrose, ferric carboxymaltose, and iron dextran, with dosing regimens varying by product.
Assessment and Monitoring
- Before initiating iron infusions, a complete blood count, iron studies including ferritin, transferrin saturation, and renal function should be assessed.
- Iron infusions work by bypassing the gastrointestinal absorption limitations of oral iron, directly replenishing iron stores and allowing for more efficient hemoglobin synthesis and red blood cell production.
Important Notes
- The safety of IV iron administration when ferritin > 500 ng/mL has not been established, and therefore caution should be exercised in these cases 1.
- The guideline provides a clear indication for iron infusions when TSAT is < 20%, but emphasizes the need for individualized decision-making and careful monitoring of patients receiving iron infusions.
From the FDA Drug Label
Inclusion criteria prior to randomization included ... ferritin ≤100 ng/mL or ferritin ≤300 ng/mL when transferrin saturation (TSAT) ≤30%. Inclusion criteria included hemoglobin (Hb) ≤11. 5 g/dL, ferritin ≤ 100 ng/mL or ferritin ≤300 ng/mL when transferrin saturation (TSAT) ≤ 30%. Iron deficiency was defined as serum ferritin <100 ng/mL or 100 to 300 ng/mL with TSAT <20%.
Iron infusions are indicated for patients with iron deficiency anemia with a transferrin saturation (TSAT) of ≤30% or <20% in certain cases 2.
From the Research
Iron Saturation Percent for Iron Infusions
- Iron infusions are indicated for patients with iron deficiency when oral preparations are ineffective or cannot be used 3, 4.
- The main treatment target for intravenous iron is an improvement of the quality of life, for which hemoglobin is a surrogate marker 5.
- Iron deficiency is diagnosed by low serum ferritin or by transferrin saturation (iron/total iron binding capacity × 100) less than 20% 4.
- According to current guidelines, iron deficiency is defined by a serum ferritin level <100 ng/ml or a transferrin saturation (TSAT) <20% if the serum ferritin level is 100-299 μg/L 6.
- A low baseline TSAT-but not serum ferritin level-appears to be a reliable indicator of the effect of intravenous iron to reduce major heart failure events 6.
- Iron deficiency state in patients with heart failure should be defined by a TSAT <20% (as long as the serum ferritin level is <400 μg/L) 6.
Key Indications for Iron Infusions
- Oral iron intolerance or poor absorption 3, 4
- Chronic inflammatory conditions (CKD, HF, IBD, cancer) 3, 4
- Ongoing blood loss 4
- During the second and third trimesters of pregnancy 4
- Severe iron deficiency anemia 7
Important Considerations
- Individual selection of the appropriate iron therapy and evaluation of treatment response are mandatory to safely deliver improved outcome through intravenous iron therapies 5.
- Adverse events occurring with intravenous iron can be anticipated according to when they typically occur, which provides a basis for educating and preparing staff and patients on how iron infusions can be administered safely and efficiently 3.