What is the first line of treatment for a patient presenting with Iron Deficiency Anemia (IDA)?

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First-Line Treatment for Iron Deficiency Anemia (IDA)

The initial treatment of Iron Deficiency Anemia (IDA) should be with one tablet per day of ferrous sulfate, fumarate or gluconate, along with addressing any underlying cause of iron loss. 1

Oral Iron Therapy

  • Oral iron supplementation is the first-line treatment for most patients with IDA due to its effectiveness, low cost, and safety 1
  • Standard dosing is ferrous sulfate 200 mg (containing 65 mg elemental iron) once daily 1, 2
  • Treatment should continue for approximately 3 months after normalization of hemoglobin levels to ensure adequate replenishment of iron stores 1
  • Patients should be monitored in the first 4 weeks for hemoglobin response to oral iron therapy 1
  • Ascorbic acid (vitamin C) may enhance iron absorption and can be considered when response to iron therapy is poor 1

Special Considerations for First-Line Treatment

Intravenous iron should be considered as first-line treatment instead of oral iron in specific situations:

  • Patients with clinically active inflammatory bowel disease 1
  • Previous intolerance to oral iron preparations 1
  • Hemoglobin below 10 g/dL 1
  • Patients who need erythropoiesis-stimulating agents 1
  • Cases where oral iron absorption is likely to be impaired 1, 3

Management of Oral Iron Intolerance

If standard dosing is not tolerated, consider these alternatives:

  • Reduced dose of one tablet every other day 1
  • Alternative oral iron preparations (ferrous gluconate, ferrous fumarate, liquid preparations) 1
  • If still not tolerated, parenteral (intravenous) iron should be considered 1

Addressing Underlying Causes

  • While initiating iron therapy, the underlying cause of IDA should be investigated and treated 1
  • Iron replacement therapy should not be deferred while awaiting investigations unless colonoscopy is imminent 1
  • In men and postmenopausal women, gastroscopy and colonoscopy should generally be the first-line GI investigations 1

Follow-up and Monitoring

  • Hemoglobin should rise by approximately 2 g/dL after 3-4 weeks of treatment 1
  • Failure to respond is usually due to poor compliance, misdiagnosis, continued blood loss, or malabsorption 1
  • Once normalized, hemoglobin concentration should be monitored at intervals (suggested every 3 months for 1 year, then after a further year) 1

Common Pitfalls to Avoid

  • Deferring iron therapy while awaiting investigations (except when colonoscopy is imminent) 1
  • Discontinuing iron therapy too early (before iron stores are replenished) 1
  • Overlooking the need to treat the underlying cause of iron deficiency 1
  • Using blood transfusions as first-line therapy (should be reserved for patients with or at risk of cardiovascular instability due to severe anemia) 1

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Management of iron deficiency.

Hematology. American Society of Hematology. Education Program, 2019

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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