Indications for Intravenous Iron in Iron Deficiency Anemia

Primary Indications for IV Iron

The American Gastroenterological Association recommends IV iron for patients who do not tolerate oral iron, when ferritin levels fail to improve with oral iron therapy, or when patients have conditions in which oral iron absorption is likely to be impaired 1, 2, 3
Oral iron intolerance is an indication for IV iron in patients who experience significant gastrointestinal side effects that prevent adherence to oral iron therapy 1, 2
Treatment failure, defined as no improvement in ferritin levels or hemoglobin despite adherence to oral iron supplementation, is an indication for IV iron 4
Impaired absorption conditions, such as post-bariatric surgery, active inflammatory bowel disease, and celiac disease, are indications for IV iron 1, 4, 5, 6
Ongoing blood loss, including portal hypertensive gastropathy and gastric antral vascular ectasia, is an indication for IV iron 4, 6, 7

In patients with chronic inflammatory conditions, such as inflammatory bowel disease, IV iron is preferred due to elevated hepcidin levels blocking oral iron absorption 1, 4
Severe anemia, defined as hemoglobin <10 g/dL, may benefit from IV iron for more rapid correction 8

The selection of IV iron formulation should prioritize those that can replace iron deficits with 1-2 infusions 9
All IV iron formulations have similar risk profiles, with true anaphylaxis being rare, and most reactions being complement activation-related pseudo-allergies 8
For mild reactions, temporarily stopping and restarting at a slower rate is often sufficient 4