What is the first line treatment for iron deficiency anemia?

First-Line Treatment for Iron Deficiency Anemia

Oral iron supplementation with ferrous sulfate 200 mg three times daily is the first-line treatment for iron deficiency anemia in patients with clinically inactive disease who have not previously been intolerant to oral iron. 1

Treatment Selection Algorithm

For Mild Anemia with Inactive Disease

• Oral iron is first-line when hemoglobin is >100 g/L (>10 g/dL), disease is clinically inactive, and no prior oral iron intolerance exists 1, 2
• Ferrous sulfate 200 mg three times daily is the simplest and cheapest option, though ferrous gluconate and ferrous fumarate are equally effective 1
• Liquid preparations may be tolerated when tablets are not 1
• Consider adding ascorbic acid to enhance absorption if response is poor 1

When to Use Intravenous Iron as First-Line

Switch to intravenous iron when any of the following are present:

• Hemoglobin <100 g/L (<10 g/dL) 1, 2
• Clinically active inflammatory disease 1, 2
• Previous intolerance to at least two oral iron preparations 1
• Need for erythropoiesis-stimulating agents 1

Dosing Specifics

Oral Iron Dosing

• Target 100-200 mg elemental iron daily 3, 4, 5
• Continue for 3 months after correction of anemia to replenish iron stores 1
• Total treatment duration typically 3-6 months 6

Intravenous Iron Dosing

For hemoglobin 100-120 g/L (women) or 100-130 g/L (men):

• 1000 mg total dose if body weight <70 kg 2
• 1500 mg total dose if body weight ≥70 kg 2

For hemoglobin 70-100 g/L:

• 1500 mg total dose if body weight <70 kg 2
• 2000 mg total dose if body weight ≥70 kg 2

Monitoring Treatment Response

• Expected response: hemoglobin rise of ≥2 g/dL within 3-4 weeks 1, 2
• Failure to respond indicates poor compliance, misdiagnosis, continued blood loss, or malabsorption 1
• Monitor hemoglobin and red cell indices every 3 months for one year, then annually 1

Treatment Goals

The goal is to normalize both hemoglobin levels AND replenish iron stores, not just correct anemia. 1, 2, 6

• Re-treat when ferritin drops below 100 μg/L or hemoglobin falls below 12 g/dL (women) or 13 g/dL (men) 2
• In remission or mild disease, measure complete blood count, ferritin, and C-reactive protein every 6-12 months 1
• In active disease, measure at least every 3 months 1

Critical Pitfalls to Avoid

• Do not use oral iron in patients with active inflammation - absorption is compromised and intravenous iron is more effective 2
• Do not use iron dextran preparations without test dosing - they carry risk of serious anaphylactic reactions 2
• Parenteral iron is painful (intramuscular), expensive, and may cause anaphylactic reactions; the rise in hemoglobin is no quicker than oral preparations 1
• Only use parenteral iron when there is intolerance to at least two oral preparations or documented non-compliance 1

Diagnostic Considerations

• In patients without active inflammation, ferritin <30 mg/L indicates iron deficiency 1
• In the presence of inflammation, ferritin up to 100 mg/L may still indicate iron deficiency 1
• Always treat the underlying cause to prevent further iron loss 1