What is the most appropriate interim management for a 36‑year‑old woman with heavy regular menstrual bleeding who has required hospitalization for symptomatic anemia while awaiting gynecologic evaluation?

Interim Management of Heavy Menstrual Bleeding with Symptomatic Anemia

Start oral ferrous sulfate 200 mg once daily immediately, add vitamin C 500 mg with each dose to enhance absorption, and continue for 3 months after hemoglobin normalizes to fully replenish iron stores. 1, 2

Immediate Iron Replacement Protocol

Oral iron therapy should be initiated without delay while awaiting gynecologic evaluation, as iron deficiency anemia from menorrhagia requires urgent treatment to prevent recurrent physiological decompensation. 1, 2

First-Line Oral Iron Regimen

• Prescribe ferrous sulfate 200 mg (65 mg elemental iron) once daily as the preferred first-line treatment due to its effectiveness and low cost. 1, 2
• Once-daily dosing is superior to multiple daily doses because hepcidin remains elevated for approximately 48 hours after iron intake, blocking additional absorption and increasing gastrointestinal side effects without improving efficacy. 1
• Add vitamin C (ascorbic acid) 500 mg with each iron dose to markedly enhance absorption, which is particularly critical given the severe iron depletion from chronic menstrual blood loss. 1, 2
• Take on an empty stomach for optimal absorption, though taking with food is acceptable if gastrointestinal side effects occur. 1
• Avoid tea and coffee for at least 1 hour after the iron dose, as these strongly inhibit absorption. 1

Alternative Formulations if Intolerant

• Ferrous fumarate or ferrous gluconate are equally effective if ferrous sulfate is not tolerated, though they are generally more expensive. 1, 2

Expected Response and Monitoring

• Check hemoglobin at 4 weeks, expecting a rise of approximately 2 g/dL (or ≥10 g/L). 1, 2
• Failure to achieve a ≥10 g/L rise by 2 weeks predicts overall treatment failure with 90.1% sensitivity and 79.3% specificity. 1
• Continue oral iron for 3 months after hemoglobin normalizes to fully replenish body iron stores; total treatment duration is typically 6-7 months. 1, 2
• Monitor hemoglobin and red cell indices every 3 months for the first year, then again after another year. 1, 2

When to Switch to Intravenous Iron

Consider IV iron if oral therapy fails or is not tolerated, using the following criteria:

• Intolerance to at least two different oral iron preparations (ferrous sulfate, ferrous fumarate, and ferrous gluconate). 1, 2
• Ferritin levels fail to improve after 4 weeks of compliant oral therapy. 1, 2
• Ongoing menstrual blood loss exceeds oral replacement capacity. 1

Preferred IV Iron Formulations

• Choose IV iron preparations that replace iron deficits in 1-2 infusions rather than multiple infusions to minimize risk and improve convenience. 1
• Ferric carboxymaltose (750-1000 mg per 15-minute infusion) is a preferred formulation; two doses ≥7 days apart provide a total of 1500 mg. 1
• All IV iron formulations have similar overall safety profiles; true anaphylaxis is rare (0.6-0.7%). 1, 2
• Most reactions are complement activation-related pseudo-allergies that respond to slowing the infusion rate. 1

Addressing Underlying Menorrhagia Simultaneously

While treating anemia, the underlying menorrhagia must be simultaneously addressed to prevent recurrence of iron deficiency. 2, 3

• Menstrual blood loss can be quantified using pictorial blood loss assessment charts, which have 80% sensitivity and specificity for detecting menorrhagia. 2
• Gynecologic evaluation should not be delayed, as definitive treatment of heavy menstrual bleeding is essential to break the cycle of recurrent iron deficiency. 2, 3, 4

Age-Specific Gastrointestinal Investigation Considerations

• For women under 45 years with menorrhagia-related anemia, focus on treating menorrhagia and iron deficiency; gastrointestinal investigation is only needed if upper GI symptoms, alarm features, or family history of colon cancer are present. 2
• For women over 45 years, consider full gastrointestinal evaluation (upper endoscopy and colonoscopy) even if menorrhagia is present, due to increasing incidence of gastrointestinal pathology with age. 2
• Screen for celiac disease with anti-endomysial antibodies and IgA measurement, as it is a common malabsorption cause in younger patients. 1

Critical Pitfalls to Avoid

• Do not prescribe multiple daily doses of oral iron, as this increases gastrointestinal side effects without improving efficacy due to hepcidin-mediated absorption blockade. 1, 2
• Do not stop iron therapy when hemoglobin normalizes; continue for 3 months to replenish stores, as premature discontinuation leads to recurrence. 1, 2
• Do not overlook vitamin C supplementation when oral iron response is suboptimal, as it significantly enhances absorption. 1, 2
• Do not normalize or delay treatment of heavy menstrual bleeding and iron deficiency, as both adversely impact quality of life, cognitive function, and work/school performance on a daily basis. 4, 5
• Do not use parenteral iron as first-line unless there is documented intolerance to at least two oral preparations. 2

Failure to Respond Algorithm

If hemoglobin fails to rise by 2 g/dL after 4 weeks despite compliant oral iron therapy:

1. Verify adherence to therapy. 1, 2
2. Assess for continued menstrual blood loss exceeding replacement capacity. 1, 2
3. Evaluate for malabsorption syndromes (celiac disease, inflammatory bowel disease). 1
4. Check for concurrent vitamin B12 or folate deficiency. 1
5. Switch to intravenous iron if oral therapy failure is confirmed. 1, 2

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

• Reassess for ongoing occult blood loss from gastrointestinal sources. 2
• Consider further investigation with upper endoscopy and colonoscopy. 2
• Verify patient adherence and consider hematology consultation for complex cases. 1

Special Considerations for Severe Anemia

For patients with hemoglobin <7 g/dL or circulatory compromise, transfusion may be necessary followed by iron replacement (preferably IV). 1, 4

• Target hemoglobin 70-90 g/L (80-100 g/L in unstable coronary artery disease). 1
• One unit of packed red cells supplies only ~200 mg elemental iron; restrictive transfusion should be followed by adequate iron replacement. 1
• Parenteral iron reliably produces a clinically meaningful hemoglobin rise within one week, making it the preferred alternative to transfusion in most cases. 1