How to manage a 35-year-old female with severe iron deficiency anemia?

Management of Severe Iron Deficiency Anemia in a 35-Year-Old Female

Start oral iron supplementation immediately with ferrous sulfate 200 mg once daily (65 mg elemental iron) taken on an empty stomach, and investigate the underlying cause of iron deficiency concurrently. 1, 2

Immediate Treatment Approach

Iron Replacement Therapy

• Begin with ferrous sulfate 200 mg once daily (65 mg elemental iron) taken in the fasting state as the optimal initial regimen balancing efficacy and tolerability 1
• Alternative formulations include ferrous fumarate (69-106 mg elemental iron) or ferrous gluconate (37 mg elemental iron) if ferrous sulfate is not tolerated 2
• Consider adding vitamin C (ascorbic acid) to enhance iron absorption, particularly if initial response is suboptimal 1, 2
• Blood transfusion is NOT indicated despite hemoglobin of 7.5 g/dL unless the patient has severe symptoms or circulatory compromise 1

Critical Monitoring Timeline

• Check hemoglobin at 2 weeks: Expect at least a 10 g/L (1 g/dL) rise; failure to achieve this predicts subsequent treatment failure with 90% sensitivity 1, 2
• Recheck hemoglobin at 4 weeks: Should see approximately 2 g/dL rise from baseline 1, 2
• Obtain complete iron studies (ferritin, serum iron, transferrin saturation, TIBC) at 4 weeks to assess response 2

Duration of Therapy

• Continue oral iron for 3 months AFTER hemoglobin normalizes to adequately replenish iron stores (ferritin goal >30-50 ng/mL) 2
• Total treatment duration typically ranges 3-6 months depending on severity and ongoing losses 3
• After normalization, monitor every 3 months for the first year, then annually 2

Investigation for Underlying Cause

For This 35-Year-Old Premenopausal Woman

• Assess menstrual blood loss history as the most common cause in this demographic 4, 5
• Screen for celiac disease with tissue transglutaminase antibody (IgA) and total IgA level 1, 3
• Upper endoscopy with duodenal biopsies is NOT routinely required in women under 40 years without upper GI symptoms 1
• Colonoscopy is NOT indicated in this age group unless there are alarm symptoms (weight loss, abdominal pain, family history of colon cancer) 1, 3
• Evaluate dietary iron intake and consider nutritional consultation 1

When to Escalate to Parenteral Iron

Consider intravenous iron if: 1, 2

• No hemoglobin rise of ≥10 g/L after 2 weeks of daily oral therapy
• Intolerance to at least two different oral iron formulations
• Malabsorption conditions identified (celiac disease, inflammatory bowel disease, post-bariatric surgery)
• Ongoing blood loss that cannot be controlled
• Patient requires rapid correction (though transfusion remains reserved for symptomatic/hemodynamic compromise)

Common Causes of Treatment Failure

If hemoglobin fails to rise appropriately, consider: 1, 2

• Poor compliance (most common)
• Continued blood loss
• Malabsorption (celiac disease, atrophic gastritis, H. pylori infection)
• Concurrent vitamin B12 or folate deficiency
• Chronic inflammation or systemic disease
• Misdiagnosis

Key Pitfalls to Avoid

• Do not stop iron therapy when hemoglobin normalizes—this is the most common error; stores must be replenished over 3 additional months 2
• Do not use modified-release preparations—they are less suitable for prescribing due to reduced bioavailability 1
• Do not give multiple daily doses—once-daily dosing maximizes absorption and minimizes side effects 1, 6
• Do not routinely perform bidirectional endoscopy in premenopausal women under 40 without alarm symptoms 1, 3
• Do not empirically supplement without physician evaluation to avoid missing serious underlying pathology 1, 7

Managing Side Effects

• If gastrointestinal side effects occur, take iron with meals (though this reduces absorption by ~40%) 7
• Consider alternate-day dosing (120 mg every other day) which may reduce nausea while maintaining similar total absorption 1, 6
• Switch to ferric maltol if traditional iron salts are not tolerated, though this is significantly more expensive 1