Treatment of Symptomatic Anemia from Heavy Menstrual Bleeding
Immediate Iron Replacement Strategy
Start oral ferrous sulfate 200 mg once daily immediately, as this is the preferred first-line treatment for iron deficiency anemia due to heavy menstrual bleeding, with proven effectiveness and lowest cost. 1
Oral Iron Therapy Protocol
Take ferrous sulfate 200 mg (containing 65 mg elemental iron) once daily rather than multiple daily doses, as once-daily dosing improves tolerability while maintaining equal or better iron absorption due to hepcidin regulation 1
Add vitamin C (ascorbic acid) 500 mg with each iron dose to enhance absorption, which is particularly critical given the ongoing blood loss 1
Take on an empty stomach for optimal absorption, though taking with food is acceptable if gastrointestinal side effects occur 1
If ferrous sulfate is not tolerated, switch to alternative formulations such as ferrous gluconate or ferrous fumarate, which are equally effective 1
Expected Response and Monitoring
Hemoglobin should rise by approximately 2 g/dL after 3-4 weeks of treatment 1
Check hemoglobin at 4 weeks to assess response 1
Continue oral iron therapy for 3 months after hemoglobin normalizes 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
Addressing the Underlying Cause
Gynecological evaluation and management of heavy menstrual bleeding is essential, as ongoing blood loss will prevent adequate response to iron therapy and represents the primary cause of iron deficiency in 5-10% of menstruating women 1, 2
Heavy menstrual bleeding is one of the most important factors contributing to iron deficiency anemia in premenopausal women 3, 4
Failure to control the source of blood loss while supplementing iron is a critical pitfall that leads to treatment failure 1
Consider pictorial blood loss assessment charts, which have 80% sensitivity and specificity for detecting menorrhagia 1
When to Switch to Intravenous Iron
Switch to intravenous iron if any of the following conditions are met:
Intolerance to at least two different oral iron preparations 1
Failure of hemoglobin to rise by 2 g/dL after 4 weeks of compliant oral therapy, indicating poor compliance, continued blood loss exceeding oral replacement capacity, or malabsorption 1, 5
Ongoing heavy menstrual bleeding that exceeds the capacity of oral iron replacement 1, 5
Conditions affecting iron absorption (inflammatory bowel disease, celiac disease, post-bariatric surgery) 1
Preferred IV Iron Formulations
Choose IV iron preparations that replace iron deficits in 1-2 infusions rather than multiple infusions to minimize inconvenience and risk 1
Ferric carboxymaltose (500-1000 mg single doses, delivered within 15 minutes) is a preferred formulation 1
Avoid iron dextran preparations due to higher risk of anaphylaxis requiring test doses 1
Critical Pitfalls to Avoid
Do not prescribe multiple daily doses of oral iron, as this increases side effects without improving efficacy due to hepcidin-mediated absorption blockade 1
Do not stop iron therapy when hemoglobin normalizes—continue for 3 months to replenish stores 1
Do not fail to address the heavy menstrual bleeding while supplementing iron, as ongoing blood loss will prevent adequate response 1, 5
Do not overlook vitamin C supplementation when oral iron response is suboptimal 1
Do not continue oral iron indefinitely without response—reassess after 4 weeks and switch to IV iron if hemoglobin fails to rise 1
Additional Diagnostic Considerations
Screen for celiac disease with antiendomysial antibody and IgA measurement, as this is a common cause of malabsorption in younger patients 1
If anemia does not resolve within 6 months despite appropriate iron therapy and control of menstrual bleeding, reassess for other sources of blood loss, evaluate for malabsorption syndromes, and verify patient adherence 1
Consider gastrointestinal evaluation if there are upper GI symptoms, rectal bleeding, family history of colon cancer, or alarm symptoms 1