What is the treatment for anemia?

Treatment of Anemia

For iron deficiency anemia, initiate oral ferrous sulfate 324 mg (65 mg elemental iron) once or twice daily between meals, and continue for 2-3 months after hemoglobin normalizes to replenish iron stores. 1, 2, 3

Initial Diagnostic Workup

Before initiating treatment, obtain the following to characterize the anemia type and guide therapy:

• Complete blood count with indices (MCV, MCH, MCHC) to classify as microcytic, normocytic, or macrocytic 1, 2
• Peripheral blood smear to confirm RBC morphology 1, 4
• Iron studies: serum ferritin, transferrin saturation, and serum iron 2
• Assessment for occult blood loss in stool and urine 1, 4
• Vitamin B12 and folate levels if macrocytic anemia is present 2

Treatment Algorithm by Etiology

Iron Deficiency Anemia

First-line therapy is oral iron supplementation:

• Ferrous sulfate 324 mg (containing 65 mg elemental iron) daily or twice daily, taken between meals to maximize absorption 1, 2, 3
• Add ascorbic acid 250-500 mg twice daily to enhance iron absorption 1, 2
• Continue treatment for 2-3 months after hemoglobin normalization to fully replenish iron stores 1, 2, 4
• Repeat hemoglobin measurement after 4 weeks to assess response 1, 2, 4

Intravenous iron is indicated when:

• Oral iron is not tolerated due to gastrointestinal side effects 1, 2, 5
• Malabsorption is present (inflammatory bowel disease, celiac disease, post-gastric bypass) 1, 2, 4
• Rapid repletion is needed 1, 2, 4
• Ongoing blood loss exceeds intestinal absorption capacity 5

Critical step for men and postmenopausal women: Investigate for gastrointestinal blood loss with endoscopy, as iron deficiency in these populations indicates bleeding until proven otherwise 6

Anemia of Chronic Disease/Inflammation

• Treat the underlying inflammatory condition as primary therapy to enhance iron absorption and utilization 1, 7
• Intravenous iron may be more effective than oral iron due to hepcidin-mediated blockade of intestinal iron absorption 7
• Erythropoiesis-stimulating agents (ESAs) may be considered in select cases, but address the underlying disease first 7

Cancer-Related Anemia

For chemotherapy-induced anemia:

• Screen renal function prior to myelosuppressive chemotherapy to identify at-risk patients 1, 2
• Evaluate for multiple potential causes: blood loss, nutritional deficiencies, bone marrow infiltration, renal dysfunction 8, 1
• ESAs may be considered only when hemoglobin ≤10 g/dL in patients receiving palliative (not curative) myelosuppressive chemotherapy without absolute iron deficiency 8, 1, 2
• Correct iron deficiency first, as functional iron deficiency is common and limits ESA response 8
• Intravenous iron is preferred over oral iron in cancer patients due to better absorption and efficacy 8

ESA therapy restrictions and risks:

• ESAs are NOT indicated for patients receiving chemotherapy with curative intent per FDA mandate 8
• Risks include venous thromboembolism, hypertension, and potential tumor progression 8, 1, 2
• Approximately 50% of eligible patients decline ESA therapy after risk-benefit discussion 8
• Monitor hemoglobin weekly initially; if no response (< 1 g/dL increase) after 4-6 weeks, escalate dose 8

Anemia in Heart Disease

Use a restrictive transfusion strategy:

• Transfuse only when hemoglobin falls to 7-8 g/dL in hospitalized patients with coronary heart disease 8, 2, 4
• Do NOT use ESAs in patients with mild to moderate anemia and congestive heart failure or coronary heart disease 8, 2
• This is a strong recommendation based on moderate-quality evidence showing no benefit and potential harm 8

Transfusion Therapy

Reserve transfusions for specific situations:

• Severe symptomatic anemia requiring rapid correction 1, 2, 4
• Hemodynamic instability 8
• Use restrictive threshold (7-8 g/dL) rather than liberal transfusion strategies 8, 1, 2, 4

Transfusion complications to monitor:

• Iron overload with repeated transfusions 1, 2, 4
• Infection transmission risk 1, 2, 4
• Immune suppression 1, 2, 4
• Note that transfused red cells do not immediately provide bioavailable iron for erythropoiesis (average lifespan 100-110 days), so iron supplementation may still be needed 8

Monitoring and Follow-up

For iron deficiency anemia:

• Repeat hemoglobin after 4 weeks of oral iron therapy 1, 2, 4
• Monitor hemoglobin and red blood cell indices every 3 months for 1 year, then annually 1, 2
• Administer additional iron if hemoglobin or MCV falls below normal 1, 2

For ESA therapy in cancer patients:

• Monitor hemoglobin weekly regardless of ESA type or dosing frequency 8
• Reduce dose by 25% (epoetin) or 40% (darbepoetin) if hemoglobin increases > 1 g/dL in any 2-week period 8

Critical Pitfalls to Avoid

• Failing to identify and treat the underlying cause leads to recurrence and treatment failure 1, 2, 4
• Using ESAs in heart failure patients with mild-moderate anemia causes harm without benefit 8, 2
• Prescribing ESAs for cancer patients on curative-intent chemotherapy violates FDA restrictions 8
• Overlooking functional iron deficiency in cancer patients limits ESA response and wastes resources 8
• Over-relying on transfusions rather than addressing correctable causes (iron deficiency, nutritional deficiencies) 1, 2
• Assuming transfused red cells provide immediately available iron—they do not, and iron supplementation may still be needed 8
• Stopping oral iron too early before iron stores are replenished (must continue 2-3 months after hemoglobin normalizes) 1, 2, 4