Management of Iron Deficiency Anemia
The management of iron deficiency anemia requires oral iron supplementation with ferrous sulfate 200 mg three times daily as first-line therapy to correct anemia and replenish iron stores, with treatment continuing for three months after hemoglobin normalization. 1
Oral Iron Therapy
- Ferrous sulfate 200 mg three times daily is the most simple, effective, and inexpensive treatment option, though ferrous gluconate and ferrous fumarate are equally effective alternatives 1
- A liquid preparation may be better tolerated when tablets cause side effects 1
- Ascorbic acid (vitamin C) enhances iron absorption and should be considered when response to iron therapy is poor 1
- Hemoglobin concentration should rise by approximately 2 g/dL after 3-4 weeks of treatment 1
- Treatment should continue for three months after correction of anemia to adequately replenish iron stores 1
Monitoring Response
- Monitor hemoglobin concentration and red cell indices at regular intervals:
- Every three months for the first year after normalization
- Once more after another year
- Any time symptoms of anemia develop 1
- If hemoglobin fails to rise appropriately after 3-4 weeks, consider:
- Poor compliance
- Misdiagnosis
- Continued blood loss
- Malabsorption 1
- Resolution of anemia should be achieved in 80% of patients by six months 1
Parenteral Iron Therapy
- Reserve parenteral iron for patients with:
- Intolerance to at least two oral iron preparations
- Non-compliance with oral therapy
- Malabsorption 1
- Available intravenous preparations include:
- Iron sucrose (Venofer)
- Ferric carboxymaltose (Ferinject/Injectafer)
- Iron dextran (Cosmofer) 1
- For patients ≥50 kg with iron deficiency anemia, ferric carboxymaltose (Injectafer) can be administered as:
- 750 mg intravenously in two doses separated by at least 7 days (total 1,500 mg)
- Or as a single dose of 15 mg/kg up to maximum 1,000 mg 2
- Cautions with parenteral iron:
- Risk of anaphylactic reactions (resuscitation facilities should be available)
- More expensive than oral therapy
- Painful when given intramuscularly 1
Special Considerations
Premenopausal Women
- Iron deficiency anemia occurs in 5-10% of menstruating women 1
- Common causes include menorrhagia, pregnancy, and breastfeeding 1
- Screening for celiac disease is recommended for all premenopausal women with IDA 1
- Gastrointestinal investigation is recommended for:
- Women ≥50 years old
- Women <50 with gastrointestinal symptoms
- Family history of colorectal cancer
- Persistent IDA after iron supplementation and correction of potential causes 1
Optimizing Oral Iron Therapy
- Recent research suggests alternate-day dosing may improve absorption and reduce side effects 3
- Morning doses may be more effective due to circadian variations in hepcidin levels 3
- Lower doses (60-120 mg) given on alternate days may optimize absorption while minimizing gastrointestinal side effects 3
Common Pitfalls and Caveats
- Failure to investigate the underlying cause of iron deficiency, especially in patients >45 years old 1
- Inadequate duration of therapy - treatment should continue for 3 months after normalization of hemoglobin 1
- Discontinuing therapy prematurely due to gastrointestinal side effects without trying alternative formulations 1
- Not considering malabsorption (e.g., celiac disease) in patients with poor response to oral iron 1
- Using parenteral iron as first-line therapy when oral iron would be appropriate 1