How should I manage a patient with laboratory-confirmed iron deficiency anemia?

Management of Laboratory-Confirmed Iron Deficiency Anemia

For a 45-year-old female patient with laboratory-confirmed iron deficiency anemia (ferritin 34, transferrin saturation 18%, hemoglobin 13 g/dL), oral iron supplementation with ferrous sulfate 200 mg three times daily should be initiated as first-line therapy, along with a comprehensive workup to identify the underlying cause. 1, 2

Diagnosis Confirmation

The patient's laboratory values confirm iron deficiency anemia:

• Hemoglobin: 13 g/dL (mildly reduced for females)
• Ferritin: 34 μg/L (borderline low)
• Transferrin saturation: 18% (<20% indicates iron deficiency)
• Blood iron: 54 (low)

These values are consistent with early iron deficiency anemia, as serum ferritin <30 μg/L without inflammation or <100 μg/L with inflammation is diagnostic of iron deficiency. 2

Treatment Algorithm

Step 1: Initiate Oral Iron Therapy

• First-line treatment: Ferrous sulfate 200 mg three times daily (provides approximately 65 mg elemental iron per dose) 1, 2
• Alternative formulations if not tolerated: Ferrous gluconate or ferrous fumarate 1
• Administration tips:
  • Take between meals or at bedtime to maximize absorption
  • Consider taking with vitamin C (ascorbic acid) to enhance absorption 2
  • If side effects occur, consider alternate-day dosing 2

Step 2: Investigate Underlying Cause

For a 45-year-old female, the following investigations are recommended:

• Upper GI endoscopy with small bowel biopsy
• Lower GI investigation (colonoscopy preferred over CT colonography)
• Screening for celiac disease (anti-tissue transglutaminase antibodies)
• Gynecological assessment for menstrual blood loss 1

Step 3: Monitor Response to Treatment

• Check hemoglobin after 3-4 weeks of therapy
  • Expected rise: approximately 2 g/dL
• If inadequate response:
  • Assess compliance
  • Consider alternative oral preparations
  • Consider IV iron if oral therapy fails 2

Step 4: Long-term Follow-up

• Monitor hemoglobin and red cell indices at 3-month intervals for one year
• Continue iron therapy for 3-6 months after normalization of hemoglobin to replenish iron stores
• Consider maintenance therapy if underlying cause cannot be corrected 2

Special Considerations

When to Consider IV Iron

• Intolerance to at least two oral iron preparations
• Non-compliance with oral therapy
• Ongoing blood loss
• Malabsorption (celiac disease, post-bariatric surgery)
• Inflammatory conditions affecting iron absorption 2, 3

Potential Side Effects of Oral Iron

• Gastrointestinal: constipation, diarrhea, nausea, abdominal pain
• Management strategies:
  • Take with food (may reduce absorption but improves tolerance)
  • Reduce dosage
  • Try different formulations
  • Consider alternate-day dosing 2

Common Pitfalls to Avoid

1. Failure to investigate the underlying cause: In a 45-year-old female, both upper and lower GI investigations are recommended regardless of symptoms, as gastrointestinal malignancy is a significant concern. 1

2. Premature discontinuation of therapy: Continue iron supplementation for 3-6 months after normalization of hemoglobin to replenish iron stores. 2

3. Inadequate monitoring: Regular follow-up is essential to confirm response to therapy and detect recurrence. 2

4. Missing concomitant conditions: Screen for celiac disease in all patients with iron deficiency anemia. 1

5. Overlooking non-GI causes: Consider gynecological causes in premenopausal women. 3

By following this structured approach, you can effectively manage iron deficiency anemia while identifying and addressing the underlying cause, thereby improving the patient's quality of life and preventing recurrence.