What is the next step in managing a patient with iron deficiency anemia?

Management of Iron Deficiency Anemia

Start oral ferrous sulfate 200 mg three times daily immediately and investigate the underlying cause based on patient age and sex. 1, 2

Immediate Iron Replacement Therapy

Your patient has clear iron deficiency anemia (low iron, low ferritin, low saturation, elevated TIBC and transferrin). All patients require iron supplementation to correct anemia and replenish body stores. 1, 2

Oral Iron Regimen

• Ferrous sulfate 200 mg three times daily is the first-line treatment—most simple, effective, and inexpensive option 1, 2
• Alternative formulations if not tolerated: ferrous gluconate or ferrous fumarate (equally effective) 1
• Add ascorbic acid (vitamin C) if response is poor, as it enhances iron absorption 1, 2
• Take with meals if gastrointestinal discomfort occurs 3
• Continue for 3 months after hemoglobin normalizes to replenish iron stores 1, 2

Expected Response

• Hemoglobin should rise by 2 g/dL after 3-4 weeks 1, 2
• Failure to respond indicates poor compliance, misdiagnosis, continued blood loss, or malabsorption 1, 2

Mandatory Investigation for Underlying Cause

The elevated haptoglobin argues against hemolysis, so focus on blood loss and malabsorption. Investigation strategy depends critically on patient age and sex: 1, 4

If Patient is Male or Postmenopausal Female (ANY AGE)

Perform bidirectional endoscopy (upper endoscopy with small bowel biopsy AND colonoscopy) to exclude gastrointestinal malignancy and celiac disease 1, 4

• Upper GI endoscopy with duodenal biopsies to exclude celiac disease, atrophic gastritis, and upper GI malignancy 1, 4
• Colonoscopy to exclude colon cancer (7 times more common than upper GI cancer in this population) 4
• 90% of patients should have both investigations unless a firm cause is found with the first 1

If Patient is Premenopausal Woman

Age-based approach: 1

Age ≥45 years:

• Investigate as above with bidirectional endoscopy 1

Age <45 years without GI symptoms:

• Check anti-endomysial antibody (IgA type) AND total IgA level to exclude celiac disease (IgA deficiency makes the test unreliable) 1
• Assess for menorrhagia, pregnancy, or breastfeeding as likely causes 1, 2
• Only perform colonoscopy if there are specific indications (GI symptoms, family history of colorectal cancer, or persistent IDA after treatment) 1, 2

Age <45 years WITH upper GI symptoms:

• Perform upper endoscopy with small bowel biopsy 1

Monitoring Protocol

Follow hemoglobin and MCV every 3 months for the first year, then once more after another year: 1, 2

• Give additional oral iron if hemoglobin or MCV falls below normal 1
• Check ferritin in doubtful cases 1
• Further investigation only needed if hemoglobin and MCV cannot be maintained 1
• 80% of patients should achieve resolution by 6 months 1, 2

When to Use Parenteral Iron

Reserve intravenous iron for specific situations only: 1, 2

• Intolerance to at least two oral iron preparations 1, 2
• Documented malabsorption 2, 4
• Non-compliance with oral therapy 1, 2

Do not use parenteral iron as first-line therapy—it is painful (intramuscular), expensive, carries anaphylactic risk, and provides no faster hemoglobin rise than oral preparations 1, 3

Critical Pitfalls to Avoid

• Never skip investigation in men or postmenopausal women—failure to investigate can miss gastrointestinal malignancy 2, 5
• Do not stop iron therapy when hemoglobin normalizes—continue for 3 months to replenish stores 1, 2
• Separate oral iron from antibiotics by 2 hours to avoid absorption interference 3
• Consider malabsorption if no response after 3-4 weeks despite compliance 1, 2
• Keep iron products away from children under 6—accidental overdose is a leading cause of fatal poisoning in this age group 3