What is the recommended treatment for iron deficiency anemia using oral iron?

Oral Iron Treatment for Iron Deficiency Anemia

Oral iron supplementation is the first-line treatment for iron deficiency anemia in patients with mild anemia, clinically inactive disease, and no previous intolerance to oral iron. 1

Diagnosis of Iron Deficiency Anemia

• Laboratory screening should include complete blood count, serum ferritin, and C-reactive protein 1
• In patients without inflammation, serum ferritin <30 μg/L indicates iron deficiency 1
• In patients with inflammation, serum ferritin up to 100 μg/L may still be consistent with iron deficiency 1

Treatment Recommendations

First-Line Therapy: Oral Iron

• Standard oral iron therapy consists of ferrous sulfate 324 mg (65 mg elemental iron) daily 2
• The goal of treatment is to normalize hemoglobin levels and replenish iron stores 1
• An acceptable response is an increase in hemoglobin of at least 2 g/dL within 4 weeks of treatment 1
• Treatment should continue for 3 months after correction of anemia to replenish iron stores 3

Dosing Strategies

• Lower doses (60-100 mg elemental iron daily) may be as effective as higher doses while causing fewer side effects 4, 5
• Alternate-day dosing (120 mg elemental iron every other day) can be considered if daily dosing causes side effects, as it may improve absorption and tolerability 6
• Adding vitamin C can improve iron absorption 7

When to Consider Intravenous Iron Instead

Intravenous iron should be considered as first-line treatment in patients with:

• Clinically active inflammatory disease 1
• Previous intolerance to oral iron 1
• Hemoglobin below 10 g/dL 1
• Need for erythropoiesis-stimulating agents 1
• Conditions where gastrointestinal blood loss exceeds intestinal ability to absorb iron 8

Monitoring and Follow-up

• Monitor hemoglobin response after 4 weeks of treatment 1
• For patients in remission or with mild disease, check iron status every 6-12 months 1
• For patients with active disease, check iron status every 3 months 1

Common Pitfalls to Avoid

• Intramuscular iron is obsolete as injections are painful, damaging to tissues, and associated with unacceptable side effects 1
• Avoid iron overload by monitoring transferrin saturation (should be below 50%) and serum ferritin (should be below 800 μg/L) 1
• Poor compliance with oral iron therapy is common due to gastrointestinal side effects; consider alternate-day dosing or switching to IV iron if side effects are significant 3, 5

Special Considerations

• In patients with inflammatory bowel disease, oral iron may exacerbate inflammation and symptoms, so IV iron may be preferred even in mild anemia 1
• For patients with portal hypertensive gastropathy, both oral and IV iron can be used, but management of portal hypertension is also essential 1