Management of Severe Iron Deficiency Anemia (Hb 6.6 g/dL) in a 45-Year-Old
Initiate oral iron therapy immediately with ferrous sulfate 200 mg once daily (or alternate days if not tolerated) while simultaneously pursuing urgent investigation for the underlying cause of blood loss, given the patient's age and severity of anemia. 1
Immediate Treatment Approach
Iron Replacement Therapy
- Start oral iron without delay - do not defer treatment while awaiting diagnostic investigations unless colonoscopy is imminent 1
- First-line oral regimen: Ferrous sulfate 200 mg once daily (65 mg elemental iron), or ferrous fumarate/gluconate equivalents 1
- Alternative dosing: If gastrointestinal side effects occur, reduce to one tablet every other day, which maintains similar iron absorption while improving tolerance 1
- Ascorbic acid supplementation should be considered if response is poor, as it enhances iron absorption 1
Monitoring Response
- Check hemoglobin at 3-4 weeks - expect a rise of approximately 2 g/dL if treatment is effective 1
- Continue iron for 3 months after hemoglobin normalizes to replenish bone marrow iron stores 1
- Monitor blood counts every 3 months for the first year, then annually to detect recurrence 1
When to Consider Intravenous Iron
Switch to IV iron if:
- Intolerance to at least two different oral iron preparations 1
- Non-compliance with oral therapy 1
- Continued blood loss despite oral supplementation 1
- Malabsorption (celiac disease, inflammatory bowel disease, post-bariatric surgery) 1, 2
- No hemoglobin response after 4 weeks of adequate oral therapy 1
IV iron dosing: Ferric gluconate 125 mg diluted in 100 mL normal saline infused over 1 hour, typically given twice monthly 3, 4
Blood Transfusion Considerations
Reserve packed red cell transfusion for:
- Hemoglobin <7-8 g/dL with severe anemia-related symptoms 1
- Cardiovascular instability or risk thereof 1
- Symptomatic patients requiring immediate hemoglobin improvement 1
Critical caveat: At Hb 6.6 g/dL, assess for symptoms of cardiovascular compromise (chest pain, dyspnea, tachycardia, lightheadedness). If present, limited transfusion may be necessary before relying solely on iron replacement 1
Mandatory Diagnostic Workup
For a 45-Year-Old Patient
This age mandates comprehensive GI investigation regardless of symptoms, as the risk of malignancy increases significantly at age 45+ 1
Required investigations:
- Upper endoscopy with duodenal biopsies to exclude gastric/duodenal pathology and celiac disease 1
- Colonoscopy or barium enema to exclude colorectal malignancy 1
- Celiac serology (tissue transglutaminase antibody with IgA level) if not already performed 1
- Helicobacter pylori testing - eradicate if present, as it can contribute to iron deficiency 1
Additional considerations:
- Review medication history for NSAIDs, aspirin, anticoagulants 1, 2
- Assess dietary iron intake 1, 2
- Check renal function (creatinine, GFR) to exclude chronic kidney disease 1
- Thyroid function tests 1
Dual Pathology Warning
Be aware that 1-10% of patients have significant bleeding sources in both upper AND lower GI tracts, with higher rates in older patients - complete both upper and lower GI investigations even if one yields a finding 1
Common Pitfalls to Avoid
- Do not wait for investigation results to start iron therapy - treatment and workup should proceed simultaneously 1
- Do not assume menstrual bleeding is the cause in a 45-year-old woman without thorough GI evaluation 1
- Do not use faecal occult blood testing - it is insensitive and non-specific for investigating iron deficiency anemia 1
- Do not prescribe three-times-daily dosing - once daily or alternate-day dosing is equally effective with better tolerance 1
- Do not give iron with food, antacids, or proton pump inhibitors - these significantly impair absorption 1