What is the first line treatment for iron deficiency anemia?

First-Line Treatment for Iron Deficiency Anemia

Oral iron supplementation is the first-line treatment for iron deficiency anemia, specifically ferrous sulfate 200 mg three times daily for at least three months after correction of anemia to replenish iron stores. 1

Diagnosis Confirmation

Before initiating treatment, confirm iron deficiency anemia with:

• Hemoglobin below normal range (per WHO definition)
• MCV < 76 fl
• Ferritin < 30 μg/L (without inflammation) or < 100 μg/L (with inflammation) 1, 2
• Transferrin saturation < 20% 2

Treatment Algorithm

1. First-Line Treatment: Oral Iron

For most patients with iron deficiency anemia:

• Ferrous sulfate 200 mg three times daily 1
• Alternative ferrous preparations with equivalent efficacy:
  • Ferrous gluconate
  • Ferrous fumarate 1, 3
• Continue for three months after normalization of hemoglobin to replenish iron stores 1

2. Special Considerations for Oral Iron

• Add ascorbic acid (vitamin C) to enhance iron absorption 1
• For patients with side effects:
  • Consider liquid preparations if tablets are not tolerated 1
  • Consider alternate-day dosing to reduce gastrointestinal side effects 2, 4
  • Try lower doses (100 mg daily) for asymptomatic patients with mild anemia 4
  • Switch between different iron formulations (ferrous gluconate or fumarate) if side effects persist 2

3. When to Use Intravenous Iron (Second-Line)

Intravenous iron should be considered as first-line in specific situations:

• Clinically active inflammatory bowel disease 1
• Previous intolerance to oral iron 1
• Hemoglobin below 100 g/L 1
• Patients requiring erythropoiesis-stimulating agents 1
• Malabsorption disorders 2, 5
• Ongoing blood loss 2
• Chronic kidney disease 2, 5
• Heart failure 2, 5
• Second and third trimesters of pregnancy when indicated 2, 5

Monitoring Response

• Check hemoglobin and red cell indices after 4 weeks of treatment 2
• Expected increase: 2 g/dL in hemoglobin after 3-4 weeks 2
• Continue monitoring every 3 months for one year, then after another year 1, 2
• Target parameters: ferritin ≥50 μg/L and transferrin saturation >20% 2

Common Pitfalls and Caveats

1. Inadequate duration of therapy: Many clinicians stop iron supplementation once hemoglobin normalizes, but treatment should continue for 3 months after normalization to replenish iron stores 1

2. Ignoring side effects: Gastrointestinal side effects (constipation, diarrhea, nausea) can reduce compliance. Consider:

   • Taking iron with food (though may reduce absorption)
   • Alternate-day dosing
   • Different iron formulations 2

3. Missing underlying causes: Always investigate and treat the underlying cause of iron deficiency (e.g., gastrointestinal bleeding, malabsorption, menorrhagia) 1, 5

4. Overlooking inflammation: In inflammatory states, ferritin may be falsely elevated. Use higher cutoff values (up to 100 μg/L) for diagnosing iron deficiency when inflammation is present 1, 2

5. Excessive dosing: Recent evidence suggests that lower doses (100 mg daily) may be sufficient for asymptomatic patients with mild anemia, with fewer side effects 4

By following this evidence-based approach to iron deficiency anemia treatment, clinicians can effectively restore hemoglobin levels and replenish iron stores while minimizing side effects and improving patient compliance.