What is the best treatment approach for patients with chronic low iron (iron deficiency)?

Treatment Approach for Chronic Iron Deficiency

Ferrous sulfate 324 mg (65 mg elemental iron) once daily is the preferred first-line treatment for chronic iron deficiency, with alternative-day dosing as an option for improved tolerability. 1

Initial Treatment Algorithm

First-Line Therapy: Oral Iron

• Formulation: Ferrous sulfate is preferred as the least expensive iron formulation 1

  • Standard dose: 324 mg (65 mg elemental iron) 2
  • No single formulation has advantages over others 1

• Dosing frequency:

  • Once daily dosing (maximum) 1
  • Consider every-other-day dosing for better tolerance with similar absorption rates 1

• Administration tips:

  • Take on an empty stomach for optimal absorption
  • Add vitamin C (such as orange juice) to improve absorption 1
  • If GI side effects occur, try:
    • Alternate-day dosing
    • Different iron formulation (ferrous gluconate or ferrous fumarate)
    • Taking with small amounts of food if necessary 3

Second-Line Therapy: Intravenous Iron

Switch to IV iron when:

1. Patient does not tolerate oral iron 1
2. Ferritin levels don't improve with oral iron trial 1
3. Patient has conditions where oral iron absorption is impaired:
   • Inflammatory bowel disease with active inflammation [1, @9@]
   • Post-bariatric surgery 1, 4
   • Celiac disease not responding to gluten-free diet [1, @13@]
   • Ongoing blood loss 5

• Preferred IV formulations: Those requiring only 1-2 infusions to replace iron deficit 1
• Safety note: True anaphylaxis is rare; most reactions are complement activation-related pseudo-allergy 1

Monitoring Response

1. Initial follow-up: Check hemoglobin after 2-4 weeks

   • Critical decision point: Increase in hemoglobin of ≥10 g/L after 2 weeks strongly predicts successful treatment 3

2. Ongoing monitoring:

   • Continue monitoring every 4 weeks until hemoglobin normalizes 3
   • Long-term follow-up: Check hemoglobin and iron studies (ferritin, TSAT) every 3 months during maintenance phase 3

Special Populations

Inflammatory Bowel Disease

• Determine if iron deficiency is due to inadequate intake/absorption or blood loss 1
• Treat active inflammation to enhance iron absorption 1
• Use IV iron therapy in those with active inflammation and compromised absorption 1

Portal Hypertensive Gastropathy

• Start with oral iron supplements 1
• Switch to IV iron if ongoing bleeding with poor response to oral therapy 1
• Consider nonselective β-blockers to treat portal hypertension 1

Celiac Disease

• Ensure adherence to gluten-free diet to improve iron absorption 1
• Consider oral iron based on severity and tolerance 1
• Use IV iron if stores don't improve 1

Post-Bariatric Surgery

• IV iron therapy is recommended, particularly after procedures that disrupt duodenal iron absorption 1

Common Pitfalls to Avoid

1. Overtreatment: Excessive iron supplementation can cause iron overload 4
2. Premature discontinuation: Continue treatment until both clinical symptoms and laboratory parameters normalize 3
3. Inadequate monitoring: Follow hemoglobin and iron studies regularly 3
4. Ignoring non-response: Evaluate for ongoing blood loss or absorption issues if no improvement 3
5. Mistaking infusion reactions for anaphylaxis: Most IV iron reactions are pseudo-allergic 1
6. Using inappropriate ferritin cutoffs in patients with inflammation 3

Iron deficiency is the most common nutritional deficiency worldwide, affecting approximately 2 billion people 5. Proper diagnosis and treatment are essential to prevent complications including fatigue, reduced exercise tolerance, and impaired cognitive function.