Ferrous Fumarate

Introduction Overview

Generic Name

ferrous fumarate

Brand Name

Ferretts Iron, Hemocyte, Femiron, Fumasorb, Ircon, Nephro-Fer, Feostat, Ferrimin 150, Ferrocite

Dosage Form

oral tablet (300 mg; 324 mg; 325 mg)

Drug Class

Iron products

Pharmacokinetics

Absorption:
Ferrous fumarate is an oral iron supplement that provides elemental iron for absorption primarily in the duodenum and upper jejunum. Upon oral administration, the iron from ferrous fumarate is absorbed in the ferrous (Fe2+) form via a saturable active transport mechanism involving divalent metal transporter 1 (DMT1) located on the apical membrane of enterocytes. Absorption is influenced by gastric acidity, dietary factors, and iron status of the individual; acidic gastric pH favors solubilization and absorption. Bioavailability of ferrous fumarate is enhanced when taken on an empty stomach, though gastrointestinal irritation often necessitates administration with food, which may reduce absorption. Co-administration of substances such as antacids, calcium, tannins in tea, and phytates in grains and legumes can impair iron absorption by forming insoluble complexes.

Distribution:
Once absorbed, iron is rapidly oxidized to the ferric (Fe3+) form and bound to transferrin, the principal iron transport protein in plasma. Transferrin-bound iron is delivered to various tissues, especially the bone marrow for erythropoiesis. Iron is stored intracellularly primarily in the liver, spleen, and bone marrow as ferritin and hemosiderin. Plasma iron levels and transferrin saturation regulate iron uptake and distribution. The volume of distribution approximates the total body iron compartment but fluctuates with iron status and ongoing utilization.

Metabolism:
Iron from ferrous fumarate itself is not metabolized enzymatically but participates in physiological metabolic pathways involving incorporation into heme and non-heme iron-containing proteins. Cellular iron homeostasis is tightly regulated by systemic factors, including hepcidin, which modulates iron absorption and release from macrophages. Excess iron can catalyze free radical formation; thus, iron is sequestered in protein complexes to prevent toxicity.

Elimination:
The human body lacks a regulated excretory pathway for iron; elimination occurs minimally through sloughing of enterocytes, skin desquamation, menstruation, and minor bleeding. Oral iron supplementation typically does not increase iron excretion but increases total body iron stores. Excessive intake, particularly in pediatric cases, can lead to iron toxicity with gastrointestinal and systemic symptoms. The half-life of plasma iron after oral administration varies depending on iron status but generally involves rapid uptake and incorporation into erythrocytes, with 120 days erythrocyte lifespan governing total turnover.

Dosage Forms

Available Dosage Forms:
Ferrous fumarate is commercially available primarily as oral tablets. The specific formulations include 300 mg, 324 mg, and 325 mg ferrous fumarate tablets. Each of these deliver approximately 106 mg elemental iron per tablet.

Dosages for Adults and Adolescents:
- For iron deficiency anemia, the usual adult dose is 360 mg/day ferrous fumarate (providing 120 mg elemental iron) administered orally in divided doses, typically 1 to 3 times daily, continued for approximately 3 months.
- For anemia associated with chronic renal failure, adults receive an initial dose of 600 mg/day ferrous fumarate (200 mg elemental iron) orally in divided doses, 1 to 3 times daily. If adequate response is not achieved after 1 to 3 months, intravenous iron supplementation may be considered.
- For vitamin/mineral supplementation, adults may take 18 to 54 mg/day ferrous fumarate (6 to 18 mg elemental iron) orally in divided doses. In individuals aged 51 and over, doses range from 15 to 24 mg/day ferrous fumarate (5 to 8 mg elemental iron) orally, in divided doses.
- Adolescents (12 years and older) are typically prescribed 1 tablet daily of 324 to 325 mg ferrous fumarate corresponding to about 106 mg elemental iron.

Specific Patient Populations:
- Pediatric dosing varies by age and indication. For iron deficiency anemia, children 0-5 years receive 9 to 18 mg/kg/day ferrous fumarate (3 to 6 mg elemental iron/kg/day). Children aged 5-12 years are prescribed 180 mg ferrous fumarate (60 mg elemental iron) daily. Adolescents males (12-18 years) generally receive 360 mg ferrous fumarate (120 mg elemental iron) daily, and females of the same age group receive 180 to 360 mg/day (60 to 120 mg elemental iron) orally in divided doses.
- For vitamin/mineral supplementation in pediatric patients and preterm infants, doses are adjusted by weight and developmental stage, for example, preterm infants less than 37 weeks gestation receive 6 mg/kg/day ferrous fumarate (2 mg elemental iron/kg/day).
- Use during pregnancy and lactation requires careful dosing evaluation, often with increased requirements due to physiologic iron demands.

Clinicians should individualize dosing based on patient tolerance, severity of anemia, iron status, and potential for adverse effects.

Mechanism Of Action

Ferrous fumarate provides supplemental iron in the ferrous (Fe2+) form, critical for the biosynthesis of hemoglobin and myoglobin. Once ingested, ferrous fumarate dissolves in the gastric environment, releasing ferrous ions that are absorbed primarily in the duodenum via divalent metal transporter 1 (DMT1). This active transport mechanism is regulated by systemic iron demands and cellular iron regulatory proteins such as hepcidin, ensuring homeostasis.

Inside enterocytes, absorbed iron is either stored within ferritin or exported into the bloodstream through ferroportin, where it is oxidized to ferric (Fe3+) form and bound to transferrin. Transferrin transports iron to the bone marrow, where it is utilized for incorporation into protoporphyrin IX to form heme, subsequently assembling into hemoglobin within red blood cells. Adequate iron availability is essential for erythropoiesis and efficient oxygen transport.

Beyond hemoglobin synthesis, iron plays critical roles in cellular respiration, DNA synthesis, and electron transport chain functions via its incorporation into various iron-containing enzymes and cytochromes. By restoring iron stores, ferrous fumarate corrects iron deficiency anemia, ameliorating symptoms related to inadequate oxygen delivery such as fatigue and pallor.

Compared with other oral iron salts, ferrous fumarate offers a higher elemental iron content and bioavailability while maintaining a tolerable safety profile. Clinical studies demonstrate that ferrous fumarate effectively increases hemoglobin and ferritin levels in deficient populations. Its mechanism is consistent with other ferrous salts, though gastrointestinal tolerability may vary, necessitating dose adjustments or adjunctive therapies for optimal adherence.

Pharmacological Actions

Acts as an iron supplement to replenish body iron stores in states of deficiency.
Supplies elemental iron essential for hemoglobin and myoglobin synthesis.
Facilitates erythropoiesis by providing bioavailable iron to developing red blood cells in bone marrow.
Supports oxygen transport and storage via restoration of hemoglobin and myoglobin function.
Participates in enzymatic processes involving iron-containing enzymes critical to cellular metabolism.
Corrects microcytic, hypochromic anemia resulting from iron deficiency.
Increases serum ferritin and transferrin saturation, reflecting improved iron status.
Improves overall energy metabolism and reduces symptoms of fatigue related to anemia.
Available orally with a higher elemental iron content compared to some other iron salts.
Exerts minimal pharmacodynamic activity outside of iron replenishment pathways.
May influence gastrointestinal motility and flora via its iron content.
Demonstrates dose-dependent absorption regulated by physiologic iron demand.
Can interact with concurrent medications influencing gastrointestinal environment or iron absorption.
Adheres to homeostatic control mechanisms mediated by hepcidin and ferroportin activity.
Enhances recovery in iron deficit from chronic blood loss, dietary insufficiency, or increased demand.

Therapeutic Or Clinical Uses

Treatment of iron deficiency anemia due to inadequate dietary intake, malabsorption, or blood loss.
Management of iron-deficiency states associated with chronic renal failure.
Iron supplementation during pregnancy and lactation to meet increased iron requirements.
Adjunctive therapy in pediatric populations with iron deficiency or prematurity-related anemia.
Prevention of iron deficiency anemia in at-risk populations including menstruating females and vegetarians.
Vitamin/mineral supplementation to maintain adequate iron levels in individuals with low dietary intake.
Correction of iron deficiency secondary to gastrointestinal disorders such as ulcerative colitis (used cautiously).
Supportive treatment in chronic diseases associated with anemia of iron deficiency type.
Supplementation during periods of rapid growth in children and adolescents.
Emergency treatment in conditions of acute blood loss as part of anemia management protocol.
Use in blood transfusion protocols to replenish depleted iron stores.
Maintaining iron balance in patients receiving erythropoiesis-stimulating agents.
Treatment of iron depletion in surgical or trauma patients prior to or after operative procedures.
Prevention of iron deficiency in patients on long-term anticoagulation therapy with risk of bleeding.
Use in nutritional rehabilitation of malnourished patients with associated iron deficiency.

Side Or Adverse Effects

Gastrointestinal irritation including abdominal cramps and discomfort.
Common incidence of constipation impacting patient adherence.
Diarrhea as an alternate manifestation of gastrointestinal intolerance.
Dark or black discoloration of stools due to unabsorbed iron excretion.
Nausea and occasional vomiting possibly exacerbated by dosing without food.
Loss of appetite secondary to gastrointestinal side effects.
Potential for serious adverse effects including hematemesis and melena indicative of gastrointestinal bleeding.
Rare but serious allergic reactions manifesting as urticaria, facial swelling, or respiratory distress.
Risk of iron overload in patients with conditions such as hemochromatosis or sideroblastic anemia.
Overdose risk particularly fatal in pediatric populations younger than 6 years of age.
Symptoms of overdose include severe stomach pain, vomiting, diarrhea, cyanosis, and coma.
Potential for dental staining if the liquid preparation contacts teeth directly (in other iron salts).
Occasional reports of metallic taste and mouth irritation.
Possible exacerbation of existing gastrointestinal diseases such as ulcers or inflammatory bowel disease.
Rarely, skin reactions or systemic hypersensitivity may occur.

Precautions

Avoid use in patients with known hypersensitivity to ferrous fumarate or any component of the formulation.
Caution in patients with a history of gastrointestinal ulcers or inflammatory bowel disease due to risk of irritation.
Monitor iron status carefully to prevent iron overload disorders especially in individuals with hemolytic anemia.
Use with caution in patients receiving blood transfusions or those with repeated transfusions.
Pregnant and lactating women require dose adjustment and medical supervision to meet increased iron needs safely.
Avoid co-administration with calcium-containing supplements or antacids close to dosing times to prevent absorption interference.
Educate patients about the signs of iron overdose and the urgent need for prompt medical attention, especially in children.
Advise patients to maintain dosing schedule and avoid missing or doubling doses to reduce adverse effects.
Regular monitoring of hemoglobin, hematocrit, and ferritin is recommended during prolonged therapy.
Use cautiously in patients with bleeding disorders, as iron may exacerbate gastric mucosal irritation.
Consider slower titration or divided doses to minimize gastrointestinal discomfort.
Dose adjustments may be necessary in chronic kidney disease and other comorbid conditions.
Inform patients that stool discoloration is common and not indicative of bleeding unless accompanied by other symptoms.
Avoid concomitant use of medications known to reduce iron absorption or alter gastrointestinal pH without medical guidance.
Ensure iron supplements are stored safely away from children to prevent accidental overdose.

Warnings

Do not use ferrous fumarate in individuals with iron overload syndromes such as hemochromatosis.
Hemolytic anemia is a contraindication due to potential exacerbation of iron accumulation.
Iron overdose can be fatal in children under 6 years; immediate emergency care is essential in suspected ingestion.
Overdosage symptoms include severe abdominal pain, vomiting blood, shock, hypovolemia, and metabolic acidosis.
Iron supplementation should not exceed recommended doses to avoid toxicity and organ damage.
Patients with peptic ulcer disease should use ferrous fumarate cautiously due to risk of gastrointestinal bleeding.
Should not be used without medical supervision for longer than six months unless directed by a healthcare provider.
Use caution in patients with a history of allergies to oral iron preparations.
The medication can interact with other drugs reducing their efficacy if taken simultaneously without appropriate timing.
Iron therapy may mask guaiac-based fecal occult blood tests; notify healthcare providers of ferrous fumarate use.
Discontinue use and seek medical attention if signs of severe allergic reaction or anaphylaxis occur.
Use with care in patients with chronic kidney disease; monitor iron indices regularly.
Administration during pregnancy and lactation requires clinical judgment to balance risks and benefits.
Educate patients on the importance of adhering to dietary recommendations to optimize therapy.
Storage warnings include keeping the medication out of reach of children to prevent accidental ingestion.

Contraindication

Known hypersensitivity to ferrous fumarate or any constituent excipients.
Iron overload disorders such as hereditary hemochromatosis or hemosiderosis.
Active hemolytic anemia where iron accumulation could worsen pathology.
Use in patients with undiagnosed anemia until diagnosis is confirmed to avoid inappropriate iron administration.
Should not be administered in cases of iron storage diseases due to risk of toxicity.
Contraindicated in patients with known gastrointestinal obstruction or inflammation exacerbated by iron.
Not recommended in pediatric patients under 6 years without direct medical supervision due to overdose risk.
Use in patients with documented intolerance to oral iron salts is contraindicated.
Patients with known active gastrointestinal bleeding should be evaluated before prescribing ferrous fumarate.
Avoid use in cases where iron is not the cause of anemia, such as anemia of chronic disease without iron deficiency.
Contraindicated in individuals with previous allergic reactions to iron supplements.
Not advised in individuals with acute infections where iron supplementation may worsen pathogen proliferation.
Contraindicated when simultaneous parenteral iron therapy is indicated and oral iron would delay appropriate treatment.
Use contraindicated if severe gastric or intestinal ulcers are present, increasing bleeding risk.
Ferrous fumarate is not suitable for use in patients with hemochromatosis without specialist oversight.

Drug Interactions

Co-administration with antacids or proton pump inhibitors can significantly reduce iron absorption.
Simultaneous use with calcium supplements decreases bioavailability of iron by forming insoluble complexes.
Certain antibiotics including tetracyclines and fluoroquinolones have reduced absorption when given with iron.
Thyroid hormone therapy may have diminished effectiveness if taken concurrently with ferrous fumarate without proper spacing.
Levodopa and Parkinson's disease medications can exhibit altered efficacy due to chelation with iron.
Bisphosphonates used in osteoporosis may have reduced absorption when administered with iron supplements.
Antiepileptic drugs like phenytoin could interact pharmacokinetically affecting drug plasma levels.
Vitamin C (ascorbic acid) enhances iron absorption but excessive co-administration may increase gastrointestinal side effects.
Concurrent use with zinc or other minerals may interfere with absorption of one or both agents.
Iron can affect certain lab test results such as fecal occult blood tests and serum iron assays.
The absorption of iron is reduced when taken with high-fiber foods, bran, tea, and coffee rich in polyphenols.
Iron enhances the potential for oxidative stress when combined with certain chemotherapeutic agents.
Chelating agents like deferoxamine impact iron bioavailability and metabolism.
Use with methyldopa may alter iron absorption and affect either drug's efficacy.
Herbal products, such as St. John's Wort, may modulate iron metabolism or drug transporter activity.

Preparations Of The Drug

Ferrous fumarate oral tablets are available in multiple strengths including 300 mg, 324 mg, and 325 mg formulations.
Each tablet typically contains approximately 106 mg elemental iron allowing for precise dosing.
Formulated for oral administration; recommended to be swallowed whole with water or liquid.
Non-extended release immediate release preparations to maximize absorption in upper gastrointestinal tract.
Some branded products include Ferretts Iron, Hemocyte, Femiron, Fumasorb, Ircon, Nephro-Fer, Feostat, Ferrimin 150, and Ferrocite.
Manufactured under Good Manufacturing Practices (GMP) ensuring product quality and consistency.
Supplied in bottles or blister packs designed to protect from moisture and degradation.
Storage recommendations include keeping at room temperature away from excessive heat, moisture, and direct light.
Available as single-agent formulations without additional vitamins or minerals; combination products exist separately.
Dosage strengths allow for tailored therapy in adult and pediatric populations.
Products generally accompanied by patient information leaflets detailing usage instructions and precautions.
Commercial availability includes both prescription and over-the-counter status depending on jurisdiction.
Generic versions provide cost-effective options for long-term iron supplementation.
Some preparations may include coloring agents and excipients to enhance tablet stability and patient compliance.
Packaging designed to minimize risk of accidental pediatric ingestion with child-resistant closures.