Iron Dextran

Introduction Overview

Generic Name

iron dextran

Brand Name

Infed

Dosage Form

Injectable solution for intravenous infusion or deep intramuscular injection

Drug Class

Iron products

Pharmacokinetics

Absorption:
Iron dextran is administered parenterally, either by intravenous infusion or deep intramuscular injection, bypassing the gastrointestinal tract to avoid poor and variable oral bioavailability associated with oral iron supplements. Following intravenous administration, iron dextran complexes are rapidly available in the plasma, where iron is released and utilized or stored. Absorption variability is minimal compared to oral iron formulations and allows correction of iron deficiency more quickly and reliably. Intramuscular administration leads to a slow release and absorption of iron into the circulation over days to weeks, providing a depot effect, but is less commonly used due to associated discomfort and risk of local reactions.

Distribution:
Once in the circulation, iron dextran is taken up by the reticuloendothelial system, primarily in the liver, spleen, and bone marrow. The dextran complex delivers iron to macrophages, which process and release elemental iron to plasma transferrin for delivery to erythroid precursors and other tissues. The volume of distribution approximates plasma and extracellular fluid compartments. The iron released contributes to the hemoglobin synthesis in developing red blood cells. Minimal free iron circulates due to tight binding to transferrin, reducing toxicity risk.

Metabolism:
The iron dextran complex undergoes biodegradation by macrophages of the reticuloendothelial system. Dextran, a polysaccharide component, is metabolized by enzymatic hydrolysis into glucose units, which enter carbohydrate metabolic pathways. The iron moiety is extracted from the complex and incorporated into the body's iron pool to be used for hemoglobin synthesis or stored in ferritin complexes. The metabolism is influenced by the body's iron requirements and homeostatic mechanisms regulating iron utilization and storage. The half-life of iron dextran in plasma is variable and depends on the dose and rate of iron release.

Elimination:
The dextran component is metabolically broken down into glucose and eliminated via normal metabolic pathways. Iron itself is predominantly conserved in the body with minimal excretion; small amounts of iron are lost via sloughing of intestinal mucosal cells, sweat, and minor bleeding. Excess iron may accumulate if dosing exceeds physiological needs, leading to potential iron overload. The elimination half-life of iron dextran ranges widely depending on the dose administered and individual patient factors. The iron is incorporated into hemoglobin or stored intracellularly, rather than being excreted in urine or bile under normal conditions.

Dosage Forms

Available Dosage Forms:
Infed is available as a sterile injectable solution for parenteral administration. The drug formulation typically contains iron dextran complex in a solution suitable for intravenous infusion or deep intramuscular injection. The commercially available preparation is usually provided in single-use vials containing 50 mg or 100 mg of elemental iron per milliliter.

Dosages for Adults and Adolescents:
The total iron requirement is calculated based on the patient’s hemoglobin deficit and body weight, often using the Ganzoni formula. Initial dosing is generally administered by slow intravenous infusion; intravenous doses up to 100 mg elemental iron are given per infusion session, repeated as necessary until the total iron deficit is corrected. The dose must be administered slowly to reduce risk of adverse reactions. For maintenance therapy or smaller deficits, smaller doses may be given as intramuscular injections, though this route is less commonly used due to local side effects.

Specific Patient Populations:
In patients with chronic kidney disease or on dialysis, iron dextran is employed to treat iron deficiency anemia where oral supplementation is inadequate or contraindicated. Caution is warranted in patients with hepatic or cardiovascular disease due to risk of iron overload or hypersensitivity. Intramuscular injection is typically avoided in pediatric patients due to pain and risk of muscle staining. Use in pregnancy is contraindicated due to potential teratogenic risks; breastfeeding safety is uncertain and requires clinical judgment. Elderly patients may require dosing adjustments due to comorbidities and altered pharmacodynamics.

Mechanism Of Action

Iron dextran functions as an intravenous or intramuscular source of iron, an essential element required for the synthesis of hemoglobin, myoglobin, and various enzymes critical for oxygen transport and cellular metabolism. Upon administration, the dextran complex facilitates the solubilization and controlled release of elemental iron into the systemic circulation. The iron released binds to the plasma protein transferrin, which transports it to the bone marrow and other tissues involved in erythropoiesis.

At the cellular level, iron delivered via transferrin is taken up by erythroid precursor cells through receptor-mediated endocytosis. Inside these cells, iron is incorporated into protoporphyrin IX to form heme, which is subsequently integrated into hemoglobin molecules. This process is vital for restoring adequate red blood cell levels in patients with iron deficiency anemia.

The dextran moiety stabilizes iron in its ferric state, minimizing free iron-induced oxidative damage and allowing a safer and more effective delivery. This mechanism contrasts with oral iron salts that can cause gastrointestinal irritation and exhibit variable absorption. Clinical studies have demonstrated that iron dextran injections rapidly replenish iron stores, leading to improved hematologic parameters and symptomatic relief.

Comparatively, iron dextran differs from newer iron formulations by its larger molecular size, longer half-life, and potential for immunologic reactions due to the dextran component. Despite this, it remains an effective option particularly in patients who cannot tolerate or absorb oral iron. Current research continues to evaluate the balance of efficacy and safety among parenteral iron preparations to optimize anemia management strategies.

Pharmacological Actions

Acts as a parenteral iron replacement to replenish body iron stores.
Provides elemental iron necessary for hemoglobin synthesis and erythropoiesis.
Facilitates iron delivery via transferrin transport in the plasma.
Enhances red blood cell production by correcting iron deficiency anemia.
Bypasses gastrointestinal absorption issues associated with oral iron therapy.
Stabilizes iron in ferric form reducing free radical generation and oxidative stress.
Dextran carrier decreases iron precipitation and improves solubility for injection.
Slow-release from reticuloendothelial cells allows sustained iron availability.
Modulates iron homeostasis through controlled iron bioavailability.
Supports correction of anemia related to chronic kidney disease or malabsorption.
Potential immunomodulatory effects due to dextran moiety stimulating immune cells.
May influence inflammatory cytokine profiles due to iron bioavailability.
Interferes with some laboratory assays due to iron and dextran interactions.
May trigger hypersensitivity reactions related to dextran antigenicity.
Promotes tissue oxygenation by increasing effective circulating hemoglobin.

Therapeutic Or Clinical Uses

Treatment of iron deficiency anemia caused by insufficient dietary intake or malabsorption.
Correction of anemia secondary to chronic kidney disease, including dialysis patients.
Repletion of iron stores in patients intolerant or unresponsive to oral iron therapy.
Management of iron deficiency anemia in patients with gastrointestinal disorders.
Preoperative anemia management to reduce need for blood transfusion.
Therapy for iron deficiency after significant blood loss or hemorrhage.
Treatment adjunct to erythropoiesis-stimulating agents in anemia.
Use in patients with chronic inflammatory diseases causing functional iron deficiency.
Anemia therapy in patients with malabsorption syndromes such as celiac disease.
Correction of anemia associated with pregnancy where oral iron is inadequate or intolerable.
Supportive treatment in anemia secondary to malignancy chemotherapy.
Management of iron deficiency in patients undergoing bariatric surgery.
Treatment of anemia in patients on long-term parenteral nutrition.
Use in pediatric patients with severe iron deficiency when oral therapy fails.
Treatment of iron deficiency anemia in individuals with compliance issues for oral supplementation.

Side Or Adverse Effects

Severe allergic reactions including anaphylaxis characterized by hives, facial swelling, and difficulty breathing.
Severe hypotension that can be potentially fatal if infusion is administered too rapidly.
Local injection site reactions such as pain, warmth, redness, swelling, and itching.
Delayed hypersensitivity reactions occurring 1 to 2 days post-injection including fever, chills, headache, and general malaise.
Gastrointestinal symptoms including nausea, vomiting, abdominal pain, and diarrhea.
Mild skin reactions such as rash or mild itching.
Neurological symptoms including dizziness, weakness, numbness, or tingling sensations.
Rare occurrence of seizure (convulsions) reported post-infusion.
Brown discoloration of the skin at or near the injection site or due to iron deposition.
Flushing or feelings of warmth and redness during or shortly after infusion.
Respiratory symptoms including wheezing or shallow breathing potentially requiring emergency intervention.
Cardiovascular symptoms including chest pain and arrhythmias such as tachycardia or bradycardia.
Blue discoloration of lips or fingernails indicating hypoxia or oxygen transport impairment.
Red or pink discoloration of urine due to hemoglobinuria or hemolysis in rare cases.
Potential for iron overload if dosing exceeds physiological requirements, leading to organ toxicity.

Precautions

Screen patients thoroughly for known allergies to iron dextran or dextran-containing products prior to administration.
Avoid use in anemia types not caused by iron deficiency to prevent potential harm.
Administer iron dextran infusions slowly under medical supervision to reduce risk of severe reactions.
Use caution in patients with history of asthma, allergies, or hypersensitivity to any medications.
Monitor patients for signs of cardiovascular instability during and after administration, especially in those with pre-existing heart disease.
Dose adjustments may be necessary in patients with liver disease due to altered metabolism.
Avoid intramuscular injections when possible due to risk of local tissue staining and pain.
Use caution in patients on beta-blocker therapy as they may be at increased risk of severe hypersensitivity reactions.
Pregnancy is a contraindication; discontinue use immediately upon pregnancy detection due to teratogenic risk in second and third trimester.
Breastfeeding safety is not established; weigh potential benefits against risks before use.
Regular monitoring of hematologic parameters and iron indices is essential to evaluate effectiveness and avoid iron overload.
Take care when administering to patients with bleeding or clotting disorders due to altered risk profiles.
Store medication properly at room temperature away from moisture and heat to maintain stability.
Properly discard any unused portion of single-use vials to avoid contamination.
Ensure accurate dosing based on patient weight and hemoglobin levels to optimize therapy and safety.

Warnings

Do not use Infed in patients with anemia not related to iron deficiency to prevent adverse outcomes.
Potential for severe and possibly fatal allergic reactions including anaphylaxis; emergency medical support must be immediately available during infusion.
Infused too rapidly, Infed can cause severe hypotension leading to dizziness, fainting, or cardiovascular collapse.
Monitor patients closely during initial doses, preferably in a hospital or clinic setting where immediate intervention is available.
Use with caution in individuals with history of asthma or multiple drug allergies as risk of hypersensitivity increases.
Pregnancy contraindicated due to potential fetal harm during second and third trimesters.
Suspicious reactions such as chest pain, wheezing, sudden shortness of breath, or flushing require immediate cessation of infusion and emergency care.
Delayed hypersensitivity reactions may occur and require medical evaluation even after discharge.
Skin discoloration and permanent staining may occur at injection sites especially with intramuscular administration.
Always check the solution appearance before administration; do not use if color changes or particulate matter are present.
Overdose can lead to iron toxicity presenting with systemic symptoms such as joint pain, chills, and vomiting requiring emergency care.
Interactions with beta-blockers may exacerbate hypersensitivity reactions; exercise extreme caution when co-administered.
Due to risk of severe side effects, administration should be limited to healthcare settings with trained personnel.
Do not reuse or share vials between patients to prevent infection or cross-contamination.
Patients should be informed about signs of allergic reactions and instructed to seek immediate care if they occur.

Contraindication

Known hypersensitivity or allergic reactions to iron dextran or other dextran-containing products.
Anemias not caused by iron deficiency such as anemia of chronic disease, hemolytic anemia, or aplastic anemia.
Patients with active systemic infections as parenteral iron can promote bacterial growth.
History of anaphylactic or severe hypersensitivity reactions to any parenteral iron preparation.
Pregnancy, especially during second and third trimesters due to potential teratogenic effects on the fetus.
Patients with iron overload syndromes such as hemochromatosis or hemosiderosis.
Severe hepatic impairment where iron metabolism and storage are compromised.
Known bleeding or clotting disorders without appropriate medical supervision.
Use in neonates and infants without established safety data and under specialist care.
Concurrent use contraindicated with beta-blockers unless absolutely necessary with close monitoring.
Patients with asthma or multiple drug allergies may require alternative therapies due to risk of hypersensitivity.
Do not administer intramuscularly in patients with bleeding tendencies to avoid hematoma formation.
Patients with a history of intramuscular iron injections resulting in severe local reactions.
Active dermatitis or skin infections at proposed injection sites.
Patients with known intolerance to any excipients in the formulation.

Drug Interactions

Concomitant use with beta-blocker medications (atenolol, carvedilol, metoprolol, propranolol, sotalol, nebivolol) may increase risk of severe hypersensitivity reactions.
Concurrent administration with oral iron supplements is generally unnecessary and may increase gastrointestinal side effects.
Potential interactions with vitamin C intake, which can increase iron absorption and risk of iron overload.
Iron dextran can interfere with absorption of certain oral antibiotics like tetracyclines and fluoroquinolones when administered concurrently.
Use with erythropoiesis-stimulating agents to enhance anemia correction, but dosage adjustments may be necessary.
Parenteral iron may alter results of some laboratory tests including serum iron, ferritin, and total iron-binding capacity assays.
Coadministration with chelating agents such as deferoxamine requires careful monitoring as these agents can bind free iron.
Increased risk of hypophosphatemia has been reported with simultaneous use of some phosphate-binding agents.
Interactions with anticoagulants may necessitate close monitoring due to effects on bleeding risk.
Drugs affecting immune response or causing hypersensitivity may exacerbate iron dextran-related allergic reactions.
Concurrent use of corticosteroids or immunosuppressants may mask or alter typical reactions to iron infusions.
Interactions with antacids or proton pump inhibitors are minimal but may impact oral iron absorption if used concurrently.
Supplemental folic acid or vitamin B12 may be necessary as part of overall anemia management alongside iron therapy.
Co-administration with herbal products containing iron should be avoided to minimize risk of iron excess.
Medication regimens with nephrotoxic drugs require monitoring to prevent compounding renal impairment risks.

Preparations Of The Drug

Infed is provided as a sterile, dark brown to black aqueous injectable solution containing iron dextran complex.
Available in single-use vials, commonly 5 mL or 10 mL, with iron content equivalent to 50 mg or 100 mg elemental iron per mL.
Formulated for intravenous infusion or deep intramuscular injection; intravenous route preferred to minimize injection site reactions.
Contains dextran as a stabilizing agent facilitating solubility and controlled iron release.
Packaged to be preservative-free, requiring aseptic technique during preparation and administration.
Each vial intended for one-time use only; discard any unused solution to prevent contamination.
Stored at controlled room temperature, protected from moisture and excessive heat to maintain stability.
No color change should occur; solution must be inspected for particulate matter or discoloration before use.
Infusion must be diluted and administered slowly according to prescribing information to reduce risk of adverse events.
Supplied with detailed instructions for preparation and administration for healthcare providers.
Can be used in clinical settings including hospitals, outpatient clinics, and dialysis centers with trained personnel.
Preparation requires reconstitution or dilution only as indicated to ensure accurate dosing and safety.
Not intended for intramuscular injection unless unavoidable, due to pain and risk of local necrosis.
Compatible with standard intravenous infusion equipment and protocols.
Manufactured under stringent quality control to ensure safety and efficacy of parenteral iron delivery.