What is the approach to treating anemia?

Approach to Treating Anemia

The optimal approach to treating anemia requires identifying the underlying cause, investigating the etiology, and implementing appropriate iron repletion strategies based on the specific type and severity of anemia. 1

Diagnosis and Classification

• Anemia is defined as a reduction in hemoglobin concentration, red-cell count, or packed cell volume below normal levels 1, 2
• Severity is classified as:
  • Mild: Hb ≤11.9 g/dl and ≥10 g/dl
  • Moderate: Hb ≤9.9 and ≥8.0 g/dl
  • Severe: Hb <8.0 g/dl 1, 3
• Initial diagnostic workup should include:
  • Complete blood count (CBC) with indices to characterize anemia 2
  • Peripheral blood smear to confirm RBC morphology 1, 2
  • Morphologic classification based on mean corpuscular volume (MCV) to identify underlying cause 2
  • Assessment for occult blood loss in stool and urine 1, 3

Treatment Algorithm by Etiology

Iron Deficiency Anemia

• First-line therapy: Oral iron supplementation with ferrous sulfate 324 mg (65 mg elemental iron) daily or twice daily between meals 1, 3
• Add ascorbic acid (250-500 mg twice daily) to improve iron absorption 1
• Continue treatment for 2-3 months after hemoglobin normalization to replenish iron stores 1, 4
• Intravenous iron therapy is indicated when:
  • Oral iron is not tolerated
  • Malabsorption is present
  • Rapid repletion is needed 1, 3
  • For patients with chronic kidney disease on hemodialysis receiving epoetin therapy 5

Anemia of Chronic Disease/Inflammation

• Treat the underlying inflammatory condition to enhance iron absorption 2, 6
• Consider intravenous iron in cases with active inflammation 2
• Avoid erythropoiesis-stimulating agents (ESAs) in patients with mild to moderate anemia and heart disease 7, 2

Vitamin B12 Deficiency Anemia

• For pernicious anemia: Intramuscular vitamin B12 100 mcg daily for 6-7 days, then alternate days for seven doses, then every 3-4 days for 2-3 weeks, followed by 100 mcg monthly for life 8
• Administer folic acid concomitantly if needed 8

Transfusion Therapy

• Use restrictive red blood cell transfusion strategy (trigger hemoglobin threshold of 7-8 g/dl) in hospitalized patients, particularly those with coronary heart disease 7, 1, 2
• Reserve transfusion for severe symptomatic anemia or when rapid correction is needed 1, 3
• Be aware of potential complications including iron overload, infection transmission, and immune suppression 1, 3

Monitoring and Follow-up

• For iron deficiency anemia: Repeat hemoglobin measurement after 4 weeks of treatment 2, 3
• Monitor hemoglobin levels and red blood cell indices every 3 months for 1 year and then annually 1
• Administer additional iron supplementation if hemoglobin or MCV fall below normal 1

Common Pitfalls to Avoid

• Failure to identify and treat the underlying cause can lead to recurrence 1, 3, 9
• Using ESAs without considering risks including hypertension, thromboembolism, and potential tumor progression in cancer patients 1, 3
• Overreliance on transfusions rather than addressing the underlying cause 1, 3
• Inadequate duration of iron therapy leading to incomplete replenishment of iron stores 4
• Neglecting to investigate gastrointestinal sources of blood loss in men and postmenopausal women with iron deficiency anemia 9

Special Considerations

• For cancer-related anemia: Evaluate for multiple potential causes and assess factors related to production, destruction, or loss of red cells 1, 2
• In inflammatory bowel disease: Intravenous iron therapy is recommended with active inflammation 2
• For chronic kidney disease patients on hemodialysis: Consider ferric gluconate for iron deficiency anemia 5