Overview
Ferrous fumarate and ferrous sulfate are oral iron supplements used to treat and prevent iron deficiency anemia. They provide elemental iron to replenish depleted iron stores and support hemoglobin synthesis. Ferrous fumarate contains approximately 33% elemental iron, while ferrous sulfate contains about 20% elemental iron. Both are commonly prescribed due to their effectiveness and relatively low cost.
Mechanism of Action
Iron is an essential component of hemoglobin, myoglobin, and various enzymes. These supplements provide ferrous iron (Fe2+), which is absorbed in the duodenum and proximal jejunum via active transport. Once absorbed, iron is incorporated into hemoglobin in developing red blood cells or stored as ferritin and hemosiderin in the liver, spleen, and bone marrow.
Indications
- Treatment of iron deficiency anemia
- Prevention of iron deficiency in high-risk populations (e.g., pregnancy, chronic blood loss, malnutrition)
Dosage
Dosage varies based on severity of deficiency and patient factors. Typical adult dose for iron deficiency anemia: 100-200 mg elemental iron daily in divided doses. For prevention: 30-60 mg elemental iron daily. Take on an empty stomach for best absorption, but may be taken with food if GI upset occurs. Avoid taking with antacids, calcium supplements, or dairy products within 2 hours.
Contraindications
- Hemochromatosis or other iron overload disorders
- Hemolytic anemia
- Known hypersensitivity to any component
- Peptic ulcer disease
- Regional enteritis
- Ulcerative colitis
Side Effects
- Gastrointestinal: nausea, vomiting, constipation, diarrhea, abdominal pain, dark stools
- Allergic reactions: rash, itching, swelling
- Rare: tooth staining (with liquid formulations)
- Very rare: anaphylaxis
Interactions
- Antacids, calcium supplements, and dairy products: decrease iron absorption
- Tetracyclines, fluoroquinolones, levothyroxine: decreased absorption of these drugs
- Vitamin C: may enhance iron absorption
- Cholestyramine: may decrease iron absorption
- Penicillamine: decreased absorption