What are the treatment options for anemia?

Anemia Treatment

For iron deficiency anemia, prescribe ferrous sulfate 200 mg once daily (or 60-120 mg elemental iron daily for adults, 3 mg/kg/day for children) taken between meals, continuing for 2-3 months after hemoglobin normalizes to replenish iron stores. 1, 2

Initial Diagnostic Requirements

Before initiating treatment, obtain:

• Complete blood count (CBC) with hemoglobin, hematocrit, MCV, and RDW to classify anemia type 1, 2
• Serum ferritin - levels <15 μg/L confirm iron deficiency in the general population 1, 2
• Transferrin saturation (TSAT) and iron studies - ferritin <100 ng/mL with TSAT <20% suggests iron deficiency 2
• Vitamin B12 and folate levels to exclude other deficiencies 3, 2

Critical caveat: In inflammatory conditions, ferritin up to 100 μg/L may still reflect iron deficiency despite appearing "normal" 2. Don't be misled by falsely elevated ferritin in the setting of inflammation.

Oral Iron Therapy (First-Line)

Dosing regimen:

• Adults: Ferrous sulfate 200 mg once daily (preferred) or 60-120 mg elemental iron daily 1, 2
• Children: 3 mg/kg per day of iron drops administered between meals 3, 1
• School-age children: One 60-mg iron tablet daily 3
• Adolescent boys: Two 60-mg iron tablets daily 3

Why ferrous sulfate? It is the gold standard due to proven effectiveness and low cost 1, 4. Recent evidence shows that lower doses (100 mg elemental iron once daily) are sufficient for symptom-free patients, with 200 mg/day reserved for severe anemia or symptomatic patients 5.

Timing matters: Administer between meals to maximize absorption 3, 1. If gastrointestinal side effects occur, consider dosing every other day rather than stopping treatment 5.

Expected response:

• Recheck hemoglobin in 4 weeks - expect an increase of ≥1 g/dL (or hematocrit ≥3%) to confirm iron deficiency diagnosis 3
• Continue treatment for 2-3 months after hemoglobin normalizes to replenish iron stores 1
• Reassess 6 months after successful treatment completion 3

Intravenous Iron Therapy (Second-Line)

Indications for IV iron:

• Oral iron not tolerated or ineffective 2, 6
• Rapid hemoglobin correction required 2
• Gastrointestinal blood loss exceeds intestinal absorption capacity 6
• Specific conditions where IV iron is preferred: active inflammatory bowel disease with Hb <10 g/dL, dialysis-dependent chronic kidney disease, heart failure 2, 5

Available formulations:

• Avoid high-molecular weight iron dextran (Dexferrum) due to increased anaphylaxis risk 3
• Safer options include low-molecular weight iron dextran, ferric gluconate, iron sucrose, and ferric carboxymaltose 3
• Ferric carboxymaltose and ferric derisomaltose allow high doses (500-1000 mg) in a single infusion 4

Critical safety consideration: Always administer IV iron in medical facilities with trained staff to manage rare hypersensitivity reactions 4. Monitor phosphate levels, especially with ferric carboxymaltose, which carries increased hypophosphatemia risk 4.

Timing caveat: Do not administer IV iron on the same day as anthracyclines due to potential cardiotoxicity potentiation 3. Avoid during neutropenia as infused iron may be used by microorganisms 3.

Special Population Considerations

Pregnant women:

• Screen at first prenatal visit 1, 2
• Start low-dose (30 mg/day) iron supplements at first prenatal visit 1
• If anemic, treat with 60-120 mg/day elemental iron 1, 2
• Refer for further evaluation if Hb <9.0 g/dL 1

Cancer patients receiving chemotherapy:

• Correct iron deficiency first before considering erythropoiesis-stimulating agents (ESAs) 3
• For absolute iron deficiency (TSAT <20%, ferritin <30 ng/mL): IV iron monotherapy preferred 3
• For functional iron deficiency (TSAT 20-50% or ferritin 30-800 ng/mL): IV iron alone or combined with ESA 3
• ESAs are contraindicated when anticipated outcome is cure per FDA mandate 3, 7
• ESAs indicated only for Hb <10 g/dL in patients receiving palliative myelosuppressive chemotherapy 3, 7

Chronic kidney disease:

• Individualize ESA therapy based on rate of Hb fall, iron therapy response, transfusion risk, and symptoms 2
• IV iron is often preferred over oral in dialysis-dependent patients 5

Heart failure:

• Define iron deficiency as ferritin <100 ng/mL or ferritin 100-300 ng/mL with TSAT <20% 2
• IV iron is the preferred treatment in this population 2

Non-Responders to Oral Iron

If anemia does not respond after 4 weeks despite compliance and absence of acute illness:

• Further evaluate with MCV, RDW, and serum ferritin 3
• Ferritin ≤15 μg/L confirms iron deficiency; >15 μg/L suggests alternative cause 3
• Investigate for underlying blood loss or malabsorption - all adults with confirmed iron deficiency anemia require upper endoscopy with duodenal biopsies and colonoscopy to exclude celiac disease and colon cancer 2

Vitamin Deficiency Correction

Before or concurrent with iron therapy:

• Folic acid 1-5 mg PO daily for 3 months if serum folate <3.4 ng/mL 3
• Vitamin B12 2000 mcg PO daily for 3 months if B12 deficient 3
• Recheck levels in 3 months 3

What NOT to Do

• Do not rely on red blood cell transfusions to correct iron deficiency - transfused iron is not immediately available for erythropoiesis (takes 100-110 days for red cell turnover) 3
• Do not use ESAs as substitute for RBC transfusions when immediate correction needed 7
• Do not prescribe excessive oral iron doses - higher doses increase side effects without improving efficacy 5
• Do not use ESAs in cancer patients receiving curative chemotherapy 3, 7