What is the first line of treatment for anemia?

First-Line Treatment for Anemia

Oral iron supplementation is the first-line treatment for iron deficiency anemia in most patients, using ferrous sulfate 200 mg (65 mg elemental iron) once daily for approximately 3 months after hemoglobin normalization. 1

Initial Diagnostic Approach

Before initiating treatment, you must:

• Identify the type of anemia through complete blood count, reticulocyte count, serum ferritin, and transferrin saturation 2
• Assess inflammatory status using C-reactive protein or ESR, as ferritin is unreliable during inflammation 2
• Determine iron deficiency thresholds based on inflammation:
  • Without inflammation: ferritin <30 μg/L indicates iron deficiency 2
  • With inflammation: ferritin <100 μg/L may still indicate iron deficiency 2
  • Transferrin saturation <16-20% suggests iron deficiency 2

First-Line Treatment by Clinical Context

Iron Deficiency Anemia (Most Common)

Standard oral iron therapy is first-line for most patients 1, 3, 4:

• Dosing: Ferrous sulfate 200 mg once daily (or ferrous fumarate/gluconate equivalent) 1
• Duration: Continue for 3 months after hemoglobin normalizes to replenish iron stores 1, 5
• Expected response: Hemoglobin should rise by approximately 2 g/dL after 3-4 weeks 1
• Monitoring: Check hemoglobin at 4 weeks to confirm response 1

Intravenous iron should be first-line instead of oral iron in these specific situations 2, 1:

• Hemoglobin <10 g/dL 2, 1
• Active inflammatory bowel disease 2, 1
• Previous intolerance to oral iron 2, 1
• Impaired intestinal absorption (celiac disease, atrophic gastritis, bariatric surgery) 1, 5
• Need for erythropoiesis-stimulating agents 2, 1

Anemia in Myelodysplastic Syndromes (Lower-Risk)

Erythropoiesis-stimulating agents (ESAs) are first-line for lower-risk MDS without del(5q) 2:

• Dosing: EPO 30,000-80,000 units weekly or darbepoetin 150-300 μg weekly 2
• Patient selection: Baseline EPO level <200-500 U/L and minimal transfusion requirements 2
• Response rate: 40-60% achieve erythroid response 2
• Response timing: Occurs within 8-12 weeks 2
• Duration: Median response 20-24 months 2

For lower-risk MDS with del(5q), lenalidomide is first-line 2:

• Dosing: 10 mg daily for 3 weeks every 4 weeks 2
• Response rate: 60-65% achieve RBC transfusion independence 2
• Caveat: TP53 mutations confer resistance and require alternative approaches 2

Anemia in Inflammatory Bowel Disease

Treating the underlying inflammation is the essential first step, though rarely sufficient alone 2:

• Iron supplementation is mandatory when iron deficiency anemia is present 2
• Oral iron (100 mg elemental iron daily) for mild anemia (Hb >10 g/dL) with inactive disease 2
• Intravenous iron for active disease, hemoglobin <10 g/dL, or oral intolerance 2

Critical pitfall: Oral iron may exacerbate IBD through reactive oxygen species generation 2

Anemia of Chronic Disease

Treat the underlying condition first 6:

• Erythropoiesis-stimulating agents may be considered if treating the underlying disease is insufficient 6
• Iron supplementation only if true iron deficiency coexists (ferritin <100 μg/L with inflammation) 2, 6

Managing Oral Iron Intolerance

If standard oral iron causes side effects 1:

• Reduce frequency to every other day 1
• Switch formulations to ferrous gluconate, ferrous fumarate, or liquid preparations 1
• Consider intravenous iron if oral forms remain intolerable 1, 3

Adjunctive Measures

• Vitamin C may enhance iron absorption when response is poor 1
• Check vitamin B12 and folate at least annually or if macrocytosis is present 2
• Address underlying cause while initiating iron therapy—do not defer treatment except when colonoscopy is imminent 1, 5

Common Pitfalls to Avoid

• Stopping iron too early: Continue for 3 months after hemoglobin normalizes to replenish stores 1, 5
• Using blood transfusions as first-line: Reserve for cardiovascular instability only 1
• Ignoring inflammatory status: Ferritin interpretation requires knowing CRP/ESR levels 2
• Failure to investigate cause: Men and postmenopausal women require bidirectional endoscopy 1, 5, 4
• Misdiagnosing anemia of chronic disease as iron deficiency: This leads to treatment refractoriness 6