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 once daily is the first-line treatment for iron deficiency anemia, providing approximately 65 mg of elemental iron. 1

Oral Iron Therapy: The Standard Approach

Recommended Formulation and Dosing

• Ferrous sulfate is the preferred oral iron formulation due to its effectiveness, low cost, and established efficacy 2, 1
• Dosing recommendations:
  • Standard dose: 200 mg once daily (providing ~65 mg elemental iron) 1
  • Traditional approach of 200 mg three times daily is no longer recommended as it causes more side effects without improving efficacy 2, 1
  • Once-daily dosing is preferred over multiple daily doses 1
  • Alternate-day dosing may be considered for better tolerance with similar absorption rates 1

Optimizing Absorption and Tolerability

• Take with 80 mg vitamin C (ascorbic acid) to enhance absorption 1
• Avoid tea and coffee within one hour of taking iron 1
• Common side effects include constipation, diarrhea, and nausea 1
• Side effects can be minimized by:
  • Taking with food if needed (though may reduce absorption)
  • Using alternate-day dosing
  • Adding vitamin C 1

Duration of Treatment

• Iron therapy should be continued for three months after correction of anemia to replenish iron stores 2
• After normalization, hemoglobin concentration and red cell indices should be monitored at three-month intervals for one year and then after a further year 2

When to Consider Intravenous Iron

Intravenous iron should be considered as first-line treatment in specific situations 2, 1:

• Patients with clinically active inflammatory bowel disease
• Previous intolerance to oral iron
• Hemoglobin below 100 g/L
• Patients requiring erythropoiesis-stimulating agents
• Poor absorption (e.g., post-bariatric surgery)
• Ongoing blood loss

Monitoring Response to Treatment

• Check hemoglobin response after 3-4 weeks of therapy (should rise by approximately 2 g/dL) 1
• Complete follow-up iron studies after 8-10 weeks of treatment 1
• If hemoglobin or MCV falls below normal during follow-up, additional oral iron should be given 2
• Further investigation is only necessary if the hemoglobin and MCV cannot be maintained with supplementation 2

Special Considerations

• In patients with inflammation, ferritin levels up to 100 μg/L may still indicate iron deficiency 2
• Patients with inflammatory conditions may have reduced oral iron absorption and may benefit from IV iron 1
• Iron supplementation should be withheld during active infections 1

Treatment Algorithm

1. Assess severity and context:

   • Mild anemia without inflammation: Oral iron first-line
   • Severe anemia (Hb <100 g/L) or with inflammation: Consider IV iron

2. Start oral iron therapy:

   • Ferrous sulfate 200 mg once daily with vitamin C
   • If side effects occur, try alternate-day dosing

3. Monitor response:

   • Check hemoglobin after 3-4 weeks
   • If inadequate response, consider switching to IV iron

4. Continue treatment:

   • Maintain therapy for 3 months after anemia correction
   • Monitor hemoglobin and red cell indices every 3 months for 1 year

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 optimizing patient outcomes.