What is the appropriate treatment for a patient with iron deficiency anemia?

Treatment of Iron Deficiency Anemia

Start oral ferrous sulfate 200 mg once daily on an empty stomach, add vitamin C 500 mg with each dose to enhance absorption, and continue for 3 months after hemoglobin normalizes to replenish iron stores. 1

Immediate Treatment Approach

Your laboratory values reveal severe iron deficiency (ferritin 22 ng/mL, iron saturation 10%, iron 43 μg/dL) with reactive thrombocytosis (platelets 508), indicating significant iron depletion requiring prompt treatment.

Oral iron is first-line therapy:

• Ferrous sulfate 200 mg once daily is the preferred formulation due to effectiveness and low cost 1
• Take on an empty stomach for optimal absorption, though taking with food is acceptable if gastrointestinal side effects occur 1
• Add vitamin C (ascorbic acid) 500 mg with each iron dose to enhance absorption, particularly critical given your severely low iron saturation of 10% 1
• Once-daily dosing is superior to multiple daily doses—it improves tolerability while maintaining effectiveness 1
• Alternative formulations (ferrous gluconate or ferrous fumarate) are equally effective if ferrous sulfate is not tolerated 1

Expected Response and Monitoring

• Hemoglobin should rise by approximately 2 g/dL after 3-4 weeks of treatment 1
• If no response occurs within 4 weeks, assess for non-adherence, malabsorption, or ongoing blood loss 1
• Continue oral iron therapy for 3 months after anemia correction to fully replenish iron stores 1
• Monitor hemoglobin and red cell indices every 3 months for the first year, then again after another year 1

When to Switch to Intravenous Iron

Consider IV iron if you meet any of these criteria:

• Intolerance to at least two different oral iron preparations 1
• Inadequate response to oral iron after 4 weeks of therapy 1
• Conditions affecting iron absorption: inflammatory bowel disease with active inflammation, celiac disease with ongoing gluten exposure, or post-bariatric surgery 2, 1
• Hemoglobin below 10 g/dL (100 g/L) with active inflammatory bowel disease 2
• Ongoing gastrointestinal blood loss exceeding oral replacement capacity 1

For IV iron, prefer formulations that can replace iron deficits with 1-2 infusions 1

Identify and Treat the Underlying Cause

Your elevated platelets (508) suggest chronic iron deficiency with reactive thrombocytosis, making identification of the underlying cause essential:

• In premenopausal women: assess menstrual blood loss patterns 3
• In men and postmenopausal women: perform gastrointestinal evaluation with upper endoscopy and colonoscopy to exclude malignancy 1, 4
• Consider celiac disease screening with antiendomysial antibody and IgA measurement 1
• Evaluate for other causes: atrophic gastritis, inflammatory bowel disease, chronic NSAID use, or dietary insufficiency 3

Critical Pitfalls to Avoid

• Do not prescribe multiple daily doses of oral iron—this increases side effects without improving efficacy 1
• Do not stop iron therapy when hemoglobin normalizes—treatment must continue for 3 months to replenish stores 1
• Do not continue oral iron indefinitely without response—reassess after 4 weeks and switch to IV iron if hemoglobin fails to rise 1
• Do not overlook vitamin C supplementation when oral iron response is suboptimal 1
• Do not fail to identify and treat the underlying cause while supplementing iron 1
• Avoid taking iron within 2 hours of tetracycline antibiotics due to absorption interference 5

If Treatment Fails

If anemia does not resolve within 6 months despite appropriate iron therapy:

• Reassess for ongoing blood loss 1
• Evaluate for malabsorption syndromes 1
• Consider further gastrointestinal investigation 1
• Verify patient adherence to therapy 1
• Consider hematology consultation for complex cases 1

Expected Side Effects

• Occasional gastrointestinal discomfort (nausea) may be minimized by taking with meals 5
• Iron-containing medication may occasionally cause black stools, constipation, or diarrhea 5
• These side effects are generally mild and do not require discontinuation unless severe 5