What is the best management approach for a 50-year-old premenopausal woman with iron deficiency anemia and menorrhagia, with elevated creatine kinase-muscle band (CK-MB) levels?

Management of Iron Deficiency Anemia with Menorrhagia at Age 50

At 50 years old with menorrhagia and iron deficiency anemia, this patient requires both immediate iron replacement and gastrointestinal investigation, as she falls into the age category where occult GI pathology becomes increasingly common despite having an obvious gynecologic source of blood loss. 1, 2

Immediate Iron Replacement Therapy

Start ferrous sulfate 200 mg once daily immediately - this is the most cost-effective first-line treatment regardless of the underlying cause. 2, 3 The once-daily dosing improves tolerability while maintaining effectiveness compared to traditional three-times-daily regimens. 3

• Add ascorbic acid (vitamin C) 500 mg with each iron dose to enhance absorption, which is particularly critical given the likely severe iron depletion. 2, 3
• Expect hemoglobin to rise by approximately 2 g/dL after 3-4 weeks of treatment. 2, 3
• Continue iron supplementation for 3 months after anemia correction to adequately replenish iron stores. 1, 2, 3
• If oral iron is not tolerated after trying at least two different formulations (ferrous gluconate or ferrous fumarate), switch to intravenous iron. 2, 3

Critical Age-Based Investigation Protocol

Because this patient is over 45 years old, she requires full gastrointestinal investigation with upper endoscopy, small bowel biopsy, and colonoscopy, even though menorrhagia is the obvious source. 1, 2 This is a critical distinction from younger menstruating women.

• The incidence of important GI pathology increases significantly after age 45, making investigation mandatory regardless of gynecologic bleeding. 1
• Upper endoscopy with small bowel biopsy should be performed to exclude celiac disease and upper GI sources. 1, 2
• Colonoscopy is indicated to exclude colonic pathology. 1
• Antiendomysial antibody testing with IgA measurement should be obtained to screen for celiac disease. 1, 2

Address the Menorrhagia

Quantify menstrual blood loss using pictorial blood loss assessment charts, which have 80% sensitivity and specificity for detecting menorrhagia. 1, 2 History alone is unreliable for quantifying menstrual loss. 1

• Consider tranexamic acid during menses to reduce menstrual blood loss while iron stores are being repleted. 4
• Gynecologic consultation for definitive management (hormonal therapy, endometrial ablation, or hysterectomy) should be pursued once hemoglobin improves to safe levels for surgical intervention if needed. 5

When to Switch to Intravenous Iron

Consider IV iron (preferably ferric carboxymaltose 500-1000 mg) if: 3, 5, 6

• Intolerance to at least two different oral iron preparations occurs. 2, 3
• No hemoglobin rise of 2 g/dL after 4 weeks of oral therapy, suggesting continued blood loss exceeding oral replacement capacity. 2, 3
• Hemoglobin is severely low (<7-8 g/dL) and rapid correction is needed before surgical intervention. 5
• Ongoing heavy menstrual bleeding prevents adequate oral iron absorption. 5

Regarding the Elevated CK-MB

The CK-MB elevation of 6.3 is likely a red herring in this clinical context and does not change the management approach for iron deficiency anemia. CK-MB can be mildly elevated in various non-cardiac conditions and should not delay iron replacement therapy. If cardiac symptoms are present, pursue cardiac evaluation separately, but this does not contraindicate iron therapy.

Monitoring Protocol

• Recheck hemoglobin at 4 weeks - failure to rise by 2 g/dL indicates poor compliance, continued blood loss, or malabsorption. 2, 3
• Monitor hemoglobin and red cell indices every 3 months for the first year after correction, then again after another year. 1, 2, 3
• Provide additional oral iron if hemoglobin or MCV falls below normal during follow-up. 1, 2

Critical Pitfalls to Avoid

• Do not skip GI investigation in this 50-year-old patient simply because menorrhagia is present - age >45 mandates full evaluation. 1, 2
• Do not delay iron supplementation while investigating the cause - treatment should begin immediately. 2
• Do not use multiple daily doses of oral iron - once-daily dosing is better tolerated with similar efficacy. 3
• Do not stop iron therapy when hemoglobin normalizes - continue for 3 months to replenish stores. 1, 2, 3
• Do not overlook vitamin C supplementation when oral iron response is suboptimal. 2, 3

Failure to Respond

If anemia does not resolve within 6 months despite appropriate iron therapy: 3

• Reassess for ongoing blood loss (both gynecologic and gastrointestinal). 3
• Evaluate for malabsorption syndromes. 3
• Verify patient adherence to therapy. 3
• Consider hematology consultation for complex cases. 3