What is the best treatment for iron deficiency anemia?

Treatment of Iron Deficiency Anemia

The best treatment for iron deficiency anemia is oral iron supplementation with ferrous sulfate 200 mg once daily, with vitamin C to enhance absorption, continued for three months after hemoglobin normalization to replenish iron stores. 1, 2

First-Line Treatment: Oral Iron Therapy

Oral Iron Formulation and Dosing

• Ferrous sulfate is preferred as the least expensive iron formulation (200 mg = 65 mg elemental iron) 1, 3
• Other effective options include ferrous fumarate (210 mg = 69 mg elemental iron) or ferrous gluconate (300 mg = 37 mg elemental iron) 2
• Give oral iron once daily at most - recent guidelines no longer recommend multiple daily doses 1
• Every-other-day dosing may be better tolerated with similar or equal absorption rates 1, 4
• Morning administration on an empty stomach is optimal for absorption 2

Enhancing Oral Iron Absorption

• Add vitamin C to oral iron supplementation to improve absorption 1, 2
• Avoid concurrent intake of tea, coffee, calcium supplements, and high-fiber foods which can inhibit absorption 2
• Increase dietary intake of iron-rich foods (both heme iron from meat and non-heme iron from plant sources) 2

Duration of Treatment

• Continue iron therapy for three months after correction of anemia to adequately replenish iron stores 2
• Monitor hemoglobin response within 4 weeks of starting therapy 2
• Expect hemoglobin to increase by approximately 2 g/dL after 3-4 weeks of treatment 2

Second-Line Treatment: Intravenous Iron Therapy

Indications for IV Iron

• Patient does not tolerate oral iron despite dose adjustments 1, 2
• Ferritin levels do not improve with a trial of oral iron (treatment failure) 1
• Patient has a condition in which oral iron is not likely to be absorbed: 1, 2, 5
  • Inflammatory bowel disease with active inflammation
  • Chronic kidney disease
  • Heart failure
  • Post-bariatric surgery
  • Malabsorption syndromes

IV Iron Administration

• IV iron formulations that can replace iron deficits with 1 or 2 infusions are preferred over those requiring multiple infusions 1
• All IV iron formulations have similar risks; true anaphylaxis is very rare 1
• Most reactions to IV iron are complement activation-related pseudo-allergy (infusion reactions) 1

Special Populations

Inflammatory Bowel Disease

• Determine whether iron deficiency anemia is due to inadequate intake/absorption or iron loss from GI bleeding 1
• Treat active inflammation effectively to enhance iron absorption or reduce iron depletion 1
• Use IV iron therapy in patients with active inflammation and compromised absorption 1

Portal Hypertensive Gastropathy

• Start with oral iron supplements to replenish iron stores 1
• Use IV iron therapy in patients with ongoing bleeding who don't respond to oral iron 1
• Consider treatment of portal hypertension with nonselective β-blockers 1

Bariatric Surgery Patients

• Use IV iron therapy in individuals who have undergone bariatric procedures, particularly those disrupting normal duodenal iron absorption 1

Monitoring and Follow-up

• Monitor hemoglobin and red cell indices at 3-month intervals for one year, then after another year 1
• Provide additional oral iron if hemoglobin or MCV falls below normal 1
• Further investigation is only necessary if hemoglobin and MCV cannot be maintained with supplementation 1

Common Pitfalls to Avoid

• Stopping treatment too early before iron stores are replenished 2
• Failing to investigate underlying causes, especially in men and postmenopausal women 2, 6
• Administering oral iron with absorption inhibitors 2
• Using excessive iron doses that cause gastrointestinal side effects and reduce compliance 4
• Overlooking the need to add vitamin C to enhance absorption 2

By following these evidence-based recommendations, iron deficiency anemia can be effectively treated while minimizing side effects and optimizing patient outcomes.