What is the best treatment for iron deficiency anemia?

Treatment of Iron Deficiency Anemia

The first-line treatment for iron deficiency anemia is oral iron supplementation with ferrous sulfate, while intravenous iron should be reserved for patients who cannot tolerate oral iron, show inadequate response, or have conditions affecting iron absorption. 1, 2

Oral Iron Therapy

• Ferrous sulfate is the preferred oral iron formulation due to its low cost and effectiveness, with no single formulation having advantages over others 1, 2
• Standard dosing: 324 mg ferrous sulfate (65 mg elemental iron) once daily 3
• Administer oral iron once daily rather than multiple times per day to improve tolerance; every-other-day dosing may be better tolerated with similar absorption rates 1, 2
• Add vitamin C to oral iron supplementation to enhance absorption 1, 2
• The hemoglobin concentration should rise by approximately 2 g/dL after 3-4 weeks of treatment; failure to do so usually indicates poor compliance, misdiagnosis, continued blood loss, or malabsorption 1, 2

When to Use Intravenous Iron

Intravenous iron should be used in the following scenarios:

• Patient does not tolerate oral iron despite trying at least two different preparations 1
• Ferritin levels do not improve with a trial of oral iron 1, 2
• Patient has a condition in which oral iron is not likely to be absorbed 1, 2
• Specific conditions where IV iron is indicated:
  • Inflammatory bowel disease with active inflammation and compromised absorption 1, 2
  • Patients who have undergone bariatric procedures, particularly those that disrupt duodenal iron absorption 1
  • Portal hypertensive gastropathy with ongoing bleeding not responding to oral therapy 1

Intravenous Iron Administration

• Prefer IV iron formulations that can replace iron deficits with 1-2 infusions 1, 2
• Be aware that true anaphylaxis with IV iron is rare; most reactions are infusion-related pseudo-allergies 1, 2
• IV iron can achieve therapeutic targets more rapidly than oral iron in certain situations, though the rise in hemoglobin is generally not quicker than with oral preparations 1, 4

Disease-Specific Approaches

• Inflammatory Bowel Disease (IBD): Determine whether iron deficiency is due to inadequate intake/absorption or blood loss; treat active inflammation to enhance iron absorption; use IV iron in patients with active inflammation 1, 2
• Portal Hypertensive Gastropathy: Begin with oral iron supplements; consider nonselective β-blockers to treat portal hypertension; switch to IV iron for ongoing bleeding not responding to oral therapy 1, 2
• Celiac Disease: Ensure adherence to a gluten-free diet to improve iron absorption; use oral iron based on severity and tolerance; switch to IV iron if stores don't improve 1
• Gastric Antral Vascular Ectasia: Consider endoscopic therapy with band ligation or thermal methods for inadequate response to iron replacement 1

Monitoring and Follow-up

• A hemoglobin increase of ≥1.0 g/dL at day 14 of oral iron therapy predicts satisfactory overall response by day 42/56 (sensitivity 90.1%, specificity 79.3%) 5
• Consider transitioning to IV iron if hemoglobin response is <1.0 g/dL at day 14 of oral therapy 5
• Continue treatment until anemia is corrected and iron stores are replenished 2
• Resolution of anemia should be achieved by six months in 80% of patients 1
• Consider further investigation if anemia doesn't resolve within 6 months 1, 2

Common Pitfalls to Avoid

• Failing to diagnose iron deficiency in patients with inflammatory conditions who may have ferritin levels >45 mg/dL (usually <100 mg/dL) 1, 2
• Continuing oral iron therapy despite poor response or intolerance 1, 2
• Not addressing the underlying cause of iron deficiency while treating the anemia 2, 6
• Overlooking the need for multidisciplinary management in complex cases 1, 2
• Using parenteral iron when oral preparations would be effective 1, 7