Iron-deficiency anemia when oral iron supplementation has not worked
This protocol addresses patients with iron-deficiency anemia whose hemoglobin and ferritin did not respond adequately to a course of oral iron — and who therefore need a different approach.
When oral iron supplementation falls short
Oral iron supplementation — typically ferrous sulfate as the preferred first-choice formulation (with ferrous fumarate or ferrous gluconate as alternatives), taken once daily or on alternate days with vitamin C added to aid absorption — is the established first-line intervention.
This protocol becomes relevant when that approach has not achieved its targets:
- Hemoglobin has not increased by at least 1 g/dL within 2 weeks of adherent therapy, or
- Ferritin has not improved within one month.
What comes next
When oral iron has not been effective or is not tolerated, intravenous iron therapy is the indicated route — with specific formulations preferred for their ability to replenish stores efficiently. Full formulation selection and clinical decision criteria are in the complete protocol.
References
DOI: 10.1016/j.cgh.2024.03.046
- 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.
- Intravenous iron formulations that can replace iron deficits with 1 or 2 infusions are preferred over those that require more than 2 infusions.
- Because there is little difference in overall efficacy of iron repletion and similar risks, formulations that can replace iron deficits with 1 to 2 infusions are preferred.