What is the recommended iron supplementation protocol for patients with iron deficiency anemia?

Iron Supplementation Protocol for Iron Deficiency Anemia

For patients with iron deficiency anemia, oral ferrous sulfate 325 mg (containing approximately 65 mg elemental iron) once daily in the morning is the recommended first-line treatment, with the option of adding vitamin C to enhance absorption. 1, 2

Diagnosis Confirmation

• Confirm iron deficiency with:
  • Serum ferritin <30 μg/L
  • Transferrin saturation <16%
  • Hemoglobin <12 g/dL (women) or <13 g/dL (men)
  • In inflammatory states, ferritin values <100 μg/L may indicate iron deficiency 2

Oral Iron Supplementation Protocol

First-Line Therapy

• Formulation: Ferrous sulfate is preferred as the least expensive iron formulation 1
• Dosing:
  • Once daily dosing (not multiple times per day) 1
  • Every-other-day dosing may be better tolerated with similar absorption rates 1, 3
• Timing: Morning administration is optimal as the circadian increase in plasma hepcidin is augmented by a morning iron dose 3
• Enhancement: Add vitamin C (250-500 mg) to oral iron supplementation to improve absorption 1, 2
• Duration: Continue treatment for three months after correction of anemia to replenish iron stores 2

Monitoring Response

• Expect hemoglobin increase of 1-2 g/dL within 4-8 weeks of starting therapy 2
• Monitor hemoglobin and reticulocyte count at 2-4 weeks
• Check ferritin and transferrin saturation at 4-8 weeks after treatment initiation 2
• An increase in hemoglobin of at least 2g/dL within 4 weeks of treatment is an acceptable response 1

Indications for Intravenous Iron Therapy

Switch to intravenous iron if:

1. Patient does not tolerate oral iron
2. Ferritin levels do not improve with a trial of oral iron (after 4-8 weeks)
3. Patient has a condition in which oral iron is not likely to be absorbed 1, 2

Specific conditions warranting first-line IV iron:

• Clinically active inflammatory bowel disease 1
• Hemoglobin below 10 g/dL 1
• Post-bariatric surgery patients 1
• Active inflammation with compromised absorption 1
• Patients requiring erythropoiesis-stimulating agents 1

Intravenous Iron Protocol

• Preferred formulations: Those that can replace iron deficits with 1-2 infusions 1
• Dosing options:
  • For patients ≥50 kg: 750 mg IV in two doses separated by at least 7 days (total 1,500 mg) 4
  • Alternative: 15 mg/kg body weight up to 1,000 mg as a single dose 4
  • For patients <50 kg: 15 mg/kg body weight in two doses separated by at least 7 days 4
• Administration: Administer as undiluted slow IV push or by infusion over at least 15 minutes 4
• Safety: All IV iron formulations have similar risks; true anaphylaxis is rare 1

Special Considerations

Patients with Inflammatory Conditions

• In inflammatory bowel disease: Treat active inflammation to enhance iron absorption 1
• In celiac disease: Ensure adherence to a gluten-free diet to improve iron absorption 1

Patients Taking Proton Pump Inhibitors

• Consider higher iron doses or longer treatment duration as PPIs may decrease oral iron absorption 5

Patients with Portal Hypertensive Gastropathy

• Start with oral iron supplements
• Switch to IV iron if patient has ongoing bleeding and doesn't respond to oral therapy 1

Common Pitfalls to Avoid

1. Overdosing: Higher doses (200 mg elemental iron) are not more effective than lower doses (80 mg) and may cause more side effects 6
2. Multiple daily doses: Once-daily dosing is as effective as multiple daily doses and improves compliance 1, 3
3. Ignoring underlying causes: Always identify and address the cause of iron deficiency 7
4. Continuing ineffective oral therapy: Switch to IV iron after 4-8 weeks if no response to oral therapy 2
5. Taking iron with inhibitors: Avoid tea and coffee around meal times as they impair absorption 2

By following this protocol, you can effectively treat iron deficiency anemia while minimizing side effects and optimizing patient outcomes.