How to treat iron deficiency anemia orally?

From the Guidelines

Oral iron supplementation is the first-line treatment for iron deficiency anemia.

Treatment Approach

• The initial dose of oral iron supplementation is typically 150-200 mg of elemental iron per day 1.
• However, some studies suggest that lower dosing or every-other-day dosing may improve tolerability and absorption 1.
• Vitamin C co-administration is commonly recommended to improve oral absorption, although the evidence supporting this practice is limited 1.
• Taking iron supplements with food or using enteric-coated formulations may improve tolerability but decrease absorption 1.

Monitoring and Follow-up

• A response to oral iron supplementation, with improvements in hemoglobin concentration, is typically evident within 1 month of treatment 1.
• If such a response is not seen, assessment for nonadherence, malabsorption, or ongoing blood loss exceeding iron intake is needed 1.

Special Considerations

• In patients with celiac disease, ensuring adherence to a gluten-free diet can improve iron absorption, and oral iron supplementation can be considered based on the severity of iron deficiency and patient tolerance 1.
• Intravenous iron may be appropriate in selected patients, such as those with impaired absorption due to prior gastric surgery, with inflammatory bowel disease or chronic kidney disease, or in whom blood loss exceeds the ability to replete iron orally 1.

From the FDA Drug Label

Purpose Iron Supplement Therapy Ferrous Sulphate is an iron supplement for iron deficiency and iron deficiency anemia when the need for such therapy has been determined by a physician. Warnings Do not exceed recommended dosage. To treat iron deficiency anemia orally, iron supplements such as Ferrous Sulphate can be used, but the treatment should be under the advice and supervision of a physician. It is recommended to:

• Not exceed the recommended dosage
• Take the supplement with meals to minimize gastrointestinal discomfort
• Not take the supplement within two hours of certain antibiotics 2 2

From the Research

Oral Iron Supplementation

Oral iron supplementation is the first line of treatment for iron deficiency anemia, with ferrous sulfate being the simplest, least expensive, and most commonly prescribed drug 3. Other ferrous salts and ferric complexes with polysaccharides or succinylated milk proteins are also widely used.

Types of Oral Iron Formulations

• Ferrous sulfate preparations are the established and standard treatment of iron deficiency, given their good bioavailability, efficacy, and acceptable tolerability 4.
• Ferric iron polymaltose complex preparations are also effective, but the debate over the advantages of ferrous versus ferric formulations is ongoing 4.
• Novel iron formulations, such as the lipophilic iron donor ferric maltol, or nanoparticle encapsulated sucrosomial® iron, have been developed in recent years 3.

Dosage and Frequency

• The optimal dosage and frequency of oral iron supplementation are still being studied, with some experts recommending doses of 150-200 mg elemental iron per day 5.
• However, recent studies suggest that lower doses, such as 60-120 mg iron as a ferrous salt given with ascorbic acid on alternate days, may be more effective in maximizing fractional iron absorption and reducing side effects 5.
• Daily low dose and every other day dosing protocols have been attempted to bypass the physiologic bottleneck of iron absorption and limit side effects, but the optimal approach is still unclear 6.

Side Effects and Compliance

• Oral iron supplementation can cause gastrointestinal side effects, such as dyspepsia and constipation, which can reduce compliance 3, 6.
• Unabsorbed iron can propagate these side effects, and excessive oral iron doses can exacerbate them 6.
• Intravenous iron therapy can be an alternative for patients who are intolerant to oral iron or have severe and/or symptomatic anemia, but it is more expensive and carries a small risk of severe infusion-related hypersensitivity reactions 7.