How to treat a patient with iron deficiency anemia, characterized by low iron, high Total Iron Binding Capacity (TIBC), low iron saturation, low ferritin, and low hemoglobin?

Treatment of Iron Deficiency Anemia

This patient requires immediate iron supplementation to correct severe iron deficiency anemia (hemoglobin 8.8 g/dL, ferritin 19.7 ng/mL, iron saturation 5.18%), and given the severity of anemia, intravenous iron should be strongly considered as first-line therapy rather than oral iron. 1

Immediate Treatment Decision

Start with intravenous (IV) iron as first-line therapy because this patient has:

• Hemoglobin below 10 g/dL (8.8 g/dL) 1
• Severe iron deficiency (ferritin 19.7 ng/mL, iron saturation 5.18%) 1
• Likely symptomatic anemia at this hemoglobin level 2

The 2020 ESPEN guidelines for inflammatory bowel disease (applicable principles for severe IDA) specifically recommend IV iron as first-line treatment when hemoglobin is below 100 g/L (10 g/dL), which applies to this patient. 1

Alternative: Oral Iron (if IV not feasible)

If IV iron is not immediately available or patient preference dictates oral therapy:

• Ferrous sulfate 325 mg once daily or every other day 2, 3
• The traditional dosing of 200 mg three times daily is outdated and based on poor-quality evidence 3
• For severe anemia like this case, 200 mg daily is appropriate 3
• Take on empty stomach with 250-500 mg vitamin C to enhance absorption 1
• If gastrointestinal side effects occur, switch to alternate-day dosing (equally effective with better tolerance) 3

Reassessment Timeline

Evaluate hemoglobin response at 14 days:

• If hemoglobin increases by ≥1.0 g/dL, continue oral iron 4
• If hemoglobin increases by <1.0 g/dL, immediately transition to IV iron 4
• This 14-day checkpoint has 90.1% sensitivity and 79.3% specificity for predicting overall response 4

Intravenous Iron Options

If IV iron is chosen (recommended for this severity):

• Ferric carboxymaltose (Ferinject): 1000 mg over 15 minutes 1
• Iron sucrose (Venofer): 200 mg over 10 minutes 1
• Low molecular weight iron dextran (Cosmofer): up to 20 mg/kg over 6 hours (requires test dose due to anaphylaxis risk) 1

The 2024 AGA guidelines note that IV iron is more effective, shows faster response, and is better tolerated than oral iron in appropriate patients. 1

Concurrent Diagnostic Workup

While initiating iron therapy, investigate the underlying cause:

Essential screening (all patients):

• Celiac disease serology (tissue transglutaminase antibody) - present in up to 4% of IDA cases 1
• Upper and lower gastrointestinal evaluation if postmenopausal female or male patient 1
• Helicobacter pylori testing 1

For premenopausal women:

• Assess menstrual blood loss (though history is unreliable) 1
• GI investigation only if age ≥50, strong family history of colorectal cancer, or persistent IDA after iron supplementation 1
• Still screen for celiac disease regardless 1

Additional considerations:

• Review medications (NSAIDs, proton pump inhibitors, H2-blockers impair iron absorption) 1, 2
• Assess dietary iron intake 1
• Check for inflammatory conditions (IBD, chronic kidney disease, heart failure) 2

Treatment Goals and Monitoring

Primary goals:

• Normalize hemoglobin (>12 g/dL women, >13 g/dL men) 1
• Replenish iron stores (ferritin >100 ng/mL) 1
• Continue iron for 3 months after hemoglobin correction to replenish stores 1

Monitoring schedule:

• Hemoglobin at 14 days (critical decision point) 4
• Hemoglobin and ferritin at 6-8 weeks 1
• Once normalized: every 3 months for 1 year, then annually 1

Critical Pitfalls to Avoid

• Do not delay treatment while awaiting diagnostic workup - start iron immediately 1
• Do not use blood transfusion unless patient has cardiovascular instability 1
• Do not continue oral iron beyond 14 days if inadequate response (<1.0 g/dL increase) 4
• Do not use faecal occult blood testing - it is insensitive and non-specific for IDA evaluation 1
• Do not assume menstrual loss explains IDA in women ≥50 years - full GI evaluation still required 1
• Do not use traditional high-dose oral iron (200 mg three times daily) - causes more side effects without better efficacy 3