What is the recommended management for iron deficiency anemia?

Management of Iron Deficiency Anemia

Oral iron supplementation is the first-line treatment for iron deficiency anemia, with a recommended dose of 60-120 mg of elemental iron daily for adults, continued for 2-3 months after hemoglobin normalizes to replenish iron stores. 1

Diagnostic Evaluation

Before initiating treatment, proper diagnosis is essential:

• Ferritin <12 μg/dl is diagnostic of iron deficiency
• Transferrin saturation <30% helps confirm diagnosis
• For patients with unexplained iron deficiency anemia:
  • Upper GI endoscopy with small bowel biopsies (to rule out celiac disease)
  • Colonoscopy (unless upper endoscopy reveals carcinoma or celiac disease)

Treatment Protocol

First-Line Therapy: Oral Iron

• Dosing options:

  • Standard: 60-120 mg elemental iron daily 1
  • Alternative: 200 mg elemental iron in 2-3 divided doses daily 1
  • Optimal regimen: 60-120 mg elemental iron as a single morning dose on alternate days (maximizes absorption and reduces side effects) 2

• Formulations:

  • Ferrous sulfate 200 mg (provides 65 mg elemental iron)
  • Ferrous gluconate and ferrous fumarate are equally effective 3
  • Liquid preparations may be better tolerated when tablets are not 3

• Enhancing absorption:

  • Add vitamin C (ascorbic acid) to enhance iron absorption 3, 1
  • Take on an empty stomach if tolerated

• Expected response:

  • Hemoglobin should rise by 2 g/dl after 3-4 weeks 3
  • Continue treatment for 2-3 months after hemoglobin normalizes 1

Second-Line Therapy: Intravenous Iron

Indications for IV iron:

• Intolerance to at least two oral preparations
• Non-compliance with oral therapy
• Ongoing blood loss exceeding oral absorption capacity
• Active inflammatory bowel disease
• After bariatric surgery
• Hemoglobin <10 g/dL requiring rapid correction
• Chronic kidney disease with poor response to oral iron

IV Iron Dosing:

• For patients ≥70 kg:

  • Hb 10-13 g/dL (men) or 10-12 g/dL (women): 1500 mg
  • Hb 7-10 g/dL: 2000 mg 1

• For patients <70 kg:

  • Hb 10-13 g/dL (men) or 10-12 g/dL (women): 1000-1500 mg
  • Hb 7-10 g/dL: 1500 mg 1

Preferred IV formulation:

• Ferric carboxymaltose (Injectafer) can be administered up to 1000 mg in a single 15-minute infusion 1, 4
• For patients ≥50 kg: 750 mg IV in two doses separated by at least 7 days (total 1500 mg) 4
• For patients <50 kg: 15 mg/kg body weight IV in two doses separated by at least 7 days 4

Special Populations

Pregnant Women

• Start with 30 mg/day at first prenatal visit
• Increase to 60-120 mg/day if anemia develops
• Decrease to 30 mg/day once hemoglobin normalizes 1

Premenopausal Women

• Common cause of IDA (5-10% of menstruating women)
• Those >45 years should be investigated according to standard guidelines
• Those <45 years with upper GI symptoms should have endoscopy and small bowel biopsy
• Those <45 years without GI symptoms should have antiendomysial antibody testing to exclude celiac disease 3

Patients with Heart Failure

• For patients with iron deficiency and mild to moderate heart failure:
  • <70 kg, Hb <10 g/dL: 1000 mg on day 1,500 mg at week 6
  • <70 kg, Hb 10-14 g/dL: 1000 mg on day 1, no dose at week 6
  • ≥70 kg, Hb <10 g/dL: 1000 mg on day 1,1000 mg at week 6
  • ≥70 kg, Hb 10-14 g/dL: 1000 mg on day 1,500 mg at week 6 4

Monitoring and Follow-up

• Hemoglobin should rise by 2 g/dL after 3-4 weeks of therapy 3

• Target values:

  • Hemoglobin >12 g/dL for women and >13 g/dL for men
  • Ferritin >100 μg/L
  • Transferrin saturation >20% 1

• If no response to oral therapy, consider:

  • Poor compliance
  • Misdiagnosis
  • Continued blood loss
  • Malabsorption 3

Common Pitfalls to Avoid

• Stopping treatment too early before iron stores are replenished 1
• Using divided doses when a single daily dose may be better tolerated 1, 2
• Failing to add vitamin C to enhance absorption 3, 1
• Using parenteral iron when oral therapy would be effective 1
• Inadequate dosing that underestimates total iron deficit 1
• Delaying iron treatment until the underlying condition resolves 1

By following these evidence-based recommendations, iron deficiency anemia can be effectively managed with improved outcomes for patients in terms of morbidity, mortality, and quality of life.