Treatment of Low Ferritin Levels with Iron Infusion

Initial Assessment and Diagnosis

Low ferritin levels indicate iron deficiency, which should be treated when associated with anemia and/or low ferritin levels 2
A full investigation of iron status should be performed in cases of anemia and persistent major fatigue 2

Intravenous iron should be used if the patient does not tolerate oral iron, ferritin levels do not improve with a trial of oral iron, or the patient has a condition in which oral iron is not likely to be absorbed, as recommended by the American Gastroenterological Association 1
Oral iron supplementation is the first-line treatment for iron deficiency 2
Typical doses of oral iron supplements are 100-200 mg/day, in divided doses 2
Ferrous sulfate is preferred as the least expensive iron formulation, according to the American Gastroenterological Association 1
Consider once-daily or alternate-day dosing to improve absorption and reduce side effects 1, 2
Adding vitamin C to oral iron supplementation improves absorption, as recommended by the American Gastroenterological Association 1

IV iron administration is indicated in patients not reaching target therapeutic goals with oral supplementation 2
IV iron administration is indicated in those requiring rapid iron repletion (e.g., before elective surgery) 2
IV iron administration is indicated in cases of repeated failure of oral therapy 2, 1
IV iron administration is indicated in patients who cannot tolerate oral iron due to gastrointestinal side effects 1
IV iron administration is indicated in conditions with impaired iron absorption (e.g., inflammatory bowel disease, bariatric surgery) 1, 3
IV iron administration is indicated in patients with active inflammation and compromised absorption 4

Intravenous iron formulations that can replace iron deficits with 1 or 2 infusions are preferred over those requiring multiple infusions, as recommended by the American Gastroenterological Association 1
For significant iron deficiency, a single IV dose of whole-body iron replacement should be given, as 1 g of iron provided as a large single dose over 15 minutes using one of the recent carbohydrate products 2
The dose should be adjusted for each patient to maintain the lowest hemoglobin level sufficient to avoid red blood cell transfusion 5

Reactions during iron infusions are very infrequent (<1:250,000 administrations with recent formulations) but may be life-threatening 2
Iron supplementation in the presence of normal or high ferritin values is not recommended and potentially harmful 2

To measure the success of treatment, basic blood tests should be repeated after 8-10 weeks 2
Do not check iron studies earlier than 8-10 weeks after iron infusion as ferritin levels are falsely high immediately after infusion 2

In patients with chronic kidney disease, IV iron may be considered despite elevated ferritin if transferrin saturation is low, as recommended by the National Kidney Foundation 3
For patients with inflammatory bowel disease and iron-deficiency anemia with active inflammation, IV iron therapy is recommended due to compromised absorption, according to the American Gastroenterological Association 4
After bariatric procedures, particularly those disrupting normal duodenal iron absorption, IV iron therapy should be used, as recommended by the American Gastroenterological Association 1

Iron overload can occur with excessive supplementation, leading to chronic fatigue, joint pain, diabetes, and end-organ failure 2
Withhold iron therapy when ferritin exceeds 1000 ng/mL or transferrin saturation exceeds 50% in dialysis patients, as recommended by the National Kidney Foundation 3
In the presence of inflammation, serum ferritin can be falsely normal despite iron deficiency; transferrin saturation is a more reliable indicator, according to the National Kidney Foundation 3