Iron Preparations (Oral)
Last updated: October 17, 2014
Trade Names: Ferrous fumarate: Ferrimin
Ferrous gluconate: Fergon
Ferrous sulfate: FeroSul, Slow FE
Drug Class: Antianemia agent (iron supplement)
Ferrous fumarate (elemental iron 33%)
Tablets: 150-, 324- and 325 mg
Ferrous gluconate (elemental iron 11.6%)
Tablets: 240-, 324- and 325 mg
Ferrous sulfate (elemental iron 20%)
Tablets: 325 mg; Extended-release tablet: 142-, 160- and 324 mg; Syrup: 300 mg/5mL
Treatment of iron deficiency anemia : 60–100 mg of elemental iron twice daily
Prophylaxis of iron deficiency: 60 mg of elemental iron daily
Indications: Prevention and treatment of iron deficiency anemia
Mechanism of Action: Replaces deficient iron stores
Contraindications: Hypersensitivity to iron preparations; hemochromatosis
Precautions: Tablets/capsules may be corrosive to the bowel. In patients with dysphagia, liquid preparations are preferred.
Monitoring: Hemoglobin and reticulocyte count to monitor response
Pregnancy Risk: A; low doses oral iron preparations are often prescribed in pregnancy
Common: GI cramps, nausea, constipation, dark stools
Less common: Diarrhea, GI ulceration
Tetracyclines: Decreased absorption of tetracycline and iron
Antacids, histamine blockers and proton pump inhibitors: Decreased iron absorption
Penicillamine: Decreased absorption of iron and penicillamine
Fluoroquinolones: Decreased absorption of antibiotic
Patient Instructions: Take regularly. May cause blackish/dark green stools or guaiac-positive tests for occult blood. Keep out of reach of children.
Comments: Many patients with inflammatory rheumatic disease have a hypochromic microcytic anemia that is not due to iron deficiency but to chronic disease. This anemia does not respond to iron therapy. Failure of an iron deficiency anemia to respond to oral therapy usually signals an incorrect diagnosis or poor compliance. Once the hemoglobin concentration has been corrected, continue prophylactic doses of iron for 3–6 months to load body iron stores.
Clinical Pharmacology: Oral absorption of iron is increased in iron deficiency anemia. Absorption is decreased by gastrectomy and achlorhydria. Absorbed iron is stored in the body and is eliminated in small amounts by cellular shedding. After starting treatment, onset of reticulocytosis is rapid (3–5 days), and hemoglobin increases within 2–4 weeks.