iron dextran
DexFerrum, InFeD

Pharmacologic classification: parenteral iron supplement
Therapeutic classification: hematinic
Pregnancy risk category C


Available forms
Available by prescription only
Injection: 50 mg elemental iron/ml in 2-ml single-dose vials

Indications and dosages
 Iron-deficiency anemia. Adults and children: Dosage is highly individualized and is based on patient’s weight and hemoglobin level. Drug is usually given I.M.; preservative-free solution can be given I.V. Check current literature for recommended protocol.

Pharmacodynamics
Hematinic action: Iron dextran is a complex of ferric hydroxide and dextran in a colloidal solution. After I.M. injection, 10% to 50% remains in the muscle for several months; remainder enters bloodstream, increasing plasma iron level for up to 2 weeks. Iron is an essential component of hemoglobin.

Pharmacokinetics
Absorption: I.M. doses are absorbed in two stages: 60% after 3 days, and up to 90% by 3 weeks. Remainder is absorbed over several months or longer.
Distribution: During first 3 days, local inflammation facilitates passage of drug into the lymphatic system; drug is then ingested by macrophages, which enter lymph and blood.
Metabolism: After I.M. or I.V. administration, iron dextran is cleared from plasma by reticuloendothelial cells of the liver, spleen, and bone marrow.
Excretion: In doses of 500 mg or less, half-life is 6 hours. Traces are excreted in breast milk, urine, bile, and feces. Drug can’t be removed by hemodialysis.

Route Onset Peak Duration
I.M., I.V. Unknown Unknown Unknown


Contraindications and precautions
Contraindicated in patients hypersensitive to drug, in those with all types of anemia except iron-deficiency anemia, and in those with acute infectious renal disease. Use cautiously in patients with impaired hepatic function, rheumatoid arthritis, and other inflammatory diseases.

Interactions
None reported.

Adverse reactions
CNS: headache, transitory paresthesia, dizziness, fever, malaise.
CV: hypotensive reaction, peripheral vascular flushing (with overly rapid I.V. administration), bradycardia.
GI: nausea, anorexia.
Musculoskeletal: arthralgia, myalgia.
Respiratory: bronchospasm, dyspnea.
Skin: rash, urticaria, purpura, brown skin discoloration (at I.M. injection site); local phlebitis (at I.V. injection site); sterile abscess; necrosis; atrophy; fibrosis.
Other: soreness, inflammation,anaphylaxis, delayed sensitivity reactions, chills.

Effects on lab test results
None reported.

Overdose and treatment
Injected iron has much greater bioavailability than oral iron, but data on acute overdose are limited.

Special considerations
• Discontinue oral iron before giving iron dextran.
• Administer a test dose of 0.5 ml iron dextrose I.M. or I.V. with monitoring for drug reactions, including anaphylaxis. Keep epinephrine (0.5 ml of a 1:1,000 solution) readily available for such an emergency.
• I.V. use is controversial, and some health care facilities don’t allow it. I.V. is route of choice if patient has insufficient muscle mass for deep injection, impaired absorption from muscle because of stasis or edema, a risk of uncontrolled I.M. bleeding from trauma (as in hemophilia), or need for massive and prolonged parenteral therapy (as in chronic substantial blood loss). Administer no more than 50 mg of iron/minute (1 ml/minute) if using drug undiluted. Vein must be flushed with 10 ml normal saline solution injection to minimize local irritation.
• Large doses (more than 250 mg iron) may color the serum brown. Iron dextran may cause false elevations of serum bilirubin level and false reductions in serum calcium level. Iron dextran prevents meaningful measurement of serum iron level and total iron binding capacity for up to 3 weeks; I.M. injection may cause dense areas of activity for 1 to 6 days on bone scans using technetium 99m diphosphonate.
Breast-feeding patients
• Traces of unmetabolized iron dextran appear in breast milk; impact on infant is unknown.
Pediatric patients
• Drug isn’t recommended for use in children younger than age 4 months.

Patient education
• Warn patient of possibility of skin staining with I.M. injections.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use