Treatment of Iron Deficiency Anemia

Oral ferrous sulfate is the first-line treatment for iron deficiency anemia due to its effectiveness, availability, and low cost. 1

First-Line Treatment

Ferrous sulfate 200 mg once daily is the preferred oral iron formulation due to its effectiveness and low cost 1
Once-daily dosing is recommended over multiple daily doses to improve tolerance while maintaining effectiveness 1
Add vitamin C (ascorbic acid) to enhance iron absorption when response is poor 1
Continue oral iron therapy for 3 months after correction of anemia to replenish iron stores 1
Expect hemoglobin to rise by approximately 2 g/dL after 3-4 weeks of treatment 1
Alternative oral iron formulations (ferrous gluconate, ferrous fumarate) may be better tolerated in some patients but have similar effectiveness 1

Intravenous iron should be used in patients who:

Cannot tolerate oral iron despite trying at least two different oral preparations 1
Show inadequate response to oral iron therapy 1, 2
Have conditions affecting iron absorption (inflammatory bowel disease with active inflammation, post-bariatric surgery) 1, 3
Have ongoing blood loss 3, 4
Have chronic kidney disease 2, 5
Have heart failure with iron deficiency 2

Prefer IV iron formulations that can replace iron deficits with 1-2 infusions 1, 3
Available IV iron options include:
- Ferric carboxymaltose (Injectafer) - can be given as a single dose up to 1000 mg 2
- Iron sucrose (Venofer) - typically given as 200 mg doses 2, 5
- Iron dextran - can be given as a total dose infusion but carries higher risk of anaphylaxis 1

Monitor hemoglobin and red cell indices at 3-month intervals for the first year after correction, then again after another year 1
Provide additional iron supplementation if hemoglobin or MCV falls below normal 1
Consider further investigation if anemia doesn't resolve within 6 months 1, 3

For inflammatory bowel disease patients: determine if iron deficiency is due to inadequate intake/absorption or blood loss, and treat underlying inflammation 1, 3
For patients with portal hypertensive gastropathy: begin with oral iron and switch to IV iron if there's inadequate response 1, 3
For pregnant women: oral iron supplementation is first-line therapy, with IV iron indicated during second and third trimesters if needed 1, 4

Failing to treat the underlying cause of iron deficiency while supplementing iron 1, 6
Continuing oral iron despite poor tolerance or inadequate response 1, 3
Using multiple daily doses of oral iron, which increases side effects without improving efficacy 1, 3
Overlooking the need for vitamin C supplementation to enhance iron absorption 1
Failing to continue iron therapy for 3 months after correction of anemia 1
Not investigating non-response to iron therapy, which may indicate ongoing blood loss, malabsorption, or incorrect diagnosis 1, 4