How to manage a patient with iron deficiency anemia?

Management of Iron Deficiency Anemia

Oral iron therapy should be initiated at no more than 100 mg elemental iron per day and continued for 3 months after normalization of hemoglobin to replenish iron stores. 1

Diagnosis Assessment

Based on the lab results provided:

• Hemoglobin: 9.3 g/dL (low)
• MCV: 101 (elevated)
• Iron saturation: 14% (low, target >20%)
• Ferritin: 14 μg/L (low, <30 μg/L indicates definitive iron deficiency)
• Reticulocyte count: 5.6% (elevated, suggesting bone marrow response)

These values confirm iron deficiency anemia with a compensatory reticulocytosis. The macrocytosis (elevated MCV) despite iron deficiency is unusual and suggests a possible mixed deficiency or other complicating factors.

Treatment Plan

Initial Iron Replacement

• Start oral iron therapy with ferrous sulfate 325 mg daily (approximately 65 mg elemental iron) or on alternate days to minimize gastrointestinal side effects 1, 2
• Consider lower doses or alternate-day dosing if GI side effects occur, as this may improve adherence while maintaining efficacy 3
• Take iron supplements on an empty stomach with vitamin C (orange juice) to enhance absorption 1
• Avoid taking iron with:
  • Tea or coffee
  • Calcium supplements
  • Antacids
  • Proton pump inhibitors (PPIs) 4

Monitoring Response

• Check hemoglobin and red cell indices at 1 month to assess initial response 1
• Continue monitoring at 3-month intervals for one year, then after a further year 1
• Target parameters:
  • Ferritin >100 μg/L (indicates adequate iron stores)
  • Transferrin saturation >20% 1

Alternative Approaches

• If oral iron is not tolerated or ineffective after an adequate trial, consider parenteral iron therapy 1, 2
• Indications for IV iron include:
  • Intolerance to at least two oral preparations
  • Poor absorption (celiac disease, post-bariatric surgery)
  • Chronic inflammatory conditions
  • Ongoing blood loss 1, 2
• IV iron options include ferric carboxymaltose, iron sucrose, and ferric derisomaltose 1

Addressing Underlying Causes

• Investigate the underlying cause of iron deficiency:
  • For men and postmenopausal women: Refer for bidirectional endoscopy (upper GI endoscopy and colonoscopy) to investigate potential GI blood loss 1
  • For premenopausal women: Evaluate for heavy menstrual bleeding 1, 2
  • Test for celiac disease with serology 1
  • Assess for other causes of malabsorption or blood loss 2

Dietary Recommendations

• Encourage consumption of iron-rich foods 1
• Add ascorbic acid (vitamin C) with meals to enhance iron absorption 1
• Avoid calcium-rich foods or supplements at the same time as iron supplements 1

Special Considerations

• The elevated MCV (101) despite iron deficiency is unusual and warrants further investigation:

  • Consider testing for vitamin B12 and folate deficiencies
  • Evaluate for potential alcohol use
  • Consider hemolysis or bone marrow disorders

• If patient is taking a PPI (like omeprazole), consider:

  • Discontinuing the PPI if clinically appropriate
  • Using higher iron doses
  • Switching to IV iron if oral therapy fails, as PPIs significantly reduce oral iron absorption 4

Common Pitfalls to Avoid

• Discontinuing iron therapy too early before replenishing iron stores 1
• Failing to investigate the underlying cause of iron deficiency 1
• Using excessive iron supplementation, which can cause iron overload in susceptible individuals 5
• Relying solely on hemoglobin improvement without monitoring iron stores (ferritin) 1
• Overlooking the potential impact of acid-reducing medications on iron absorption 4