What is the treatment plan for a 49-year-old female with iron deficiency anemia, as indicated by low iron levels, high Total Iron-Binding Capacity (TIBC), and low iron saturation?

Treatment Plan for Iron Deficiency Anemia in a 49-Year-Old Female

The patient should be treated with oral ferrous sulfate 60-120 mg of elemental iron daily (equivalent to 324 mg ferrous sulfate tablet taken 1-2 times daily) and investigated for underlying causes of iron deficiency anemia, particularly gastrointestinal sources of blood loss. 1

Diagnosis Confirmation

The laboratory results clearly indicate iron deficiency anemia:

• Low iron saturation (14%, reference range 20-55%)
• High TIBC (451 mcg/dL, reference range 228-428 mcg/dL)
• Low ferritin (15 ng/mL, just at the lower limit of normal range 11-336 ng/mL)
• Normal hemoglobin (12.6 g/dL) but with laboratory evidence of iron deficiency

The AGA recommends using a ferritin cutoff of 45 ng/mL for diagnosing iron deficiency, and this patient's ferritin of 15 ng/mL is well below this threshold. 1

Treatment Algorithm

1. Iron Supplementation

• First-line therapy: Oral ferrous sulfate 324 mg (65 mg elemental iron) 1-2 times daily 1, 2

  • This provides 65-130 mg of elemental iron daily, within the recommended range of 60-120 mg/day
  • Take on an empty stomach if tolerated, with vitamin C to enhance absorption
  • Common side effects include constipation, nausea, and black stools

• Monitoring response:

  • Hemoglobin should rise by approximately 2 g/dL after 3-4 weeks 1
  • A hemoglobin increase <1.0 g/dL at day 14 may identify patients who should be transitioned to IV iron 3
  • Continue treatment for 3 months after hemoglobin normalizes to replenish iron stores 1

• Alternative options if oral iron is not tolerated:

  • Try a different oral preparation (ferrous gluconate or ferrous fumarate)
  • Consider liquid preparations if tablets are not tolerated
  • Parenteral iron should only be used when there is intolerance to at least two oral preparations or documented non-compliance 1, 4

2. Diagnostic Workup for Underlying Cause

Since the patient is 49 years old, a thorough investigation for the source of iron deficiency is warranted:

• Bidirectional endoscopy (upper endoscopy and colonoscopy) is strongly recommended for postmenopausal women and men with iron deficiency anemia 1

  • At age 49, the patient is approaching menopause, and the risk of significant GI pathology increases with age
  • Upper endoscopy should include duodenal biopsies to rule out celiac disease

• Additional testing:

  • Test for H. pylori infection (non-invasive testing followed by treatment if positive) 1
  • Consider celiac disease testing with serology first, followed by small bowel biopsy only if positive 1
  • Assess menstrual blood loss as a potential cause (pictorial blood loss assessment charts may be helpful) 1

Follow-up Plan

1. Monitor hemoglobin and red cell indices at 4 weeks to assess response to iron therapy
2. If hemoglobin increases by <1.0 g/dL at 2 weeks, consider switching to IV iron 3
3. Once normal, monitor hemoglobin and red cell indices every 3 months for one year, then after a further year 1
4. Additional oral iron should be given if hemoglobin or MCV falls below normal
5. Further investigation is necessary if hemoglobin cannot be maintained with iron supplementation

Common Pitfalls and Caveats

• Inadequate dosing: Many providers prescribe insufficient elemental iron doses; ensure 60-120 mg of elemental iron daily
• Premature discontinuation: Iron therapy should continue for 3 months after correction of anemia to replenish iron stores
• Failure to investigate: In a 49-year-old woman, gastrointestinal causes of blood loss must be ruled out, even if menstrual bleeding is present
• Poor adherence: Side effects often lead to non-compliance; discuss strategies to improve tolerance (taking with food if needed, despite reduced absorption)
• Misdiagnosis: Anemia of chronic disease can be mistaken for iron deficiency; the high TIBC in this case confirms true iron deficiency

By following this treatment plan, the patient's iron deficiency anemia should resolve within 3-4 months, while the diagnostic workup will help identify and address any underlying causes to prevent recurrence.