IV iron Pregnancy: Parenteral iron administration may be associated with hypersensitivity reactions which may have serious consequences such as fetal bradycardia; advise pregnant persons of the potential risk to the fetus. Available data from postmarketing reports are insufficient to assess the risk of major birth defects or miscarriage, and there are risks to the pregnant person and fetus from untreated iron deficiency anaemia. Iron dextran has been shown to be teratogenic and embryocidal in mice, rats, rabbits, dogs and monkeys at about 3 times the maximum human dose (US label section 8.1).

Iron dextran

Brand names: CosmoFer

Iron dextran is a parenteral iron preparation used to treat iron-deficiency anaemia when oral iron is ineffective, not tolerated or unsuitable.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Individually calculated total dose (not a fixed dose) — for iron deficiency anaemia, read the total volume from the label's Table 1 or calculate it for adults and children over 15 kg as: Dose (mL) = 0.0442 x (Desired Hb - Observed Hb) x LBW + (0.26 x LBW). Each 1 mL contains 50 mg of iron (100 mg/2 mL single-dose vials).

Route: Intravenous (undiluted, slow injection) or intramuscular (into the buttock). A test dose of 0.5 mL by the intended route must be given before the first therapeutic dose.

Frequency: Administer daily doses of no more than 2 mL (100 mg) until the total calculated requirement has been given; continue until haemoglobin is within the normal range and iron stores are replete

Max: Maximum daily dose 2 mL (100 mg). Intravenous administration is given undiluted at a slow gradual rate not exceeding 50 mg (1 mL) per minute.

US label section 2.2 (iron deficiency anaemia): in the formula above, Desired Hb is the target haemoglobin in g/dL (normal haemoglobin for males and females of body weight over 15 kg is taken as 14.8 g/dL), Observed Hb is the patient's current haemoglobin in g/dL, and LBW is lean body weight in kg (use actual body weight if it is less than lean body weight). LBW for males = 50 kg + 2.3 kg for each inch of height over 5 feet; LBW for females = 45.5 kg + 2.3 kg for each inch of height over 5 feet. SECTION 2.3 — IRON REPLACEMENT FOR BLOOD LOSS: Dose (mL) = [blood loss (mL) x haematocrit] / 50 mg/mL, based on the approximation that 1 mL of normocytic, normochromic red cells contains 1 mg of elemental iron (example: 500 mL blood loss at 20% haematocrit = 100 mg replacement iron). SECTION 2.1 — PRE-TREATMENT: discontinue any iron-containing products before administration, and assess baseline haemoglobin, haematocrit, serum iron, total iron binding capacity and percent transferrin saturation to monitor response. Serum ferritin may not be an accurate measure of body iron stores in patients on chronic dialysis. SECTION 2.4 — TEST DOSE: before the first intravenous therapeutic dose give an intravenous test dose of 0.5 mL at a gradual rate over at least 30 seconds; before the first intramuscular therapeutic dose give an intramuscular test dose of 0.5 mL over at least 30 seconds into the buttock. Delay the initial therapeutic dose until 1 hour or more after the test dose. If a hypersensitivity reaction occurs with the test dose, manage medically and do not administer further doses. Do not mix with other medications or add to parenteral nutrition solutions. PAEDIATRIC: the label gives a weight-only formula for children 5 to 15 kg (11 to 33 lb) — Dose (mL) = 0.0442 x (Desired Hb - Observed Hb) x W + (0.26 x W), where W is body weight in kg and normal haemoglobin for children of 15 kg or less is taken as 12 g/dL. This is a calculated volume rather than a simple mg/kg regimen, so no structured per-kg paediatric dose is given here. Not recommended for use in infants under 4 months of age; intramuscular iron dextran in neonates has been associated with an increased incidence of gram-negative sepsis in reports from outside the US. Verify all paediatric dosing against a children's formulary before prescribing. SOURCE: no UK SPC was fetched in this bundle — this draft is distilled from the US prescribing information and must be verified against the UK SPC.

Dose auto-extracted from US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Previous demonstrated hypersensitivity to iron dextran

Side effects

Hypersensitivity reactions, including anaphylactic-type reactions (a labelled boxed warning; a test dose is mandatory before the first therapeutic dose)
Delayed reactions, and increased risk of toxicity in patients with underlying conditions
Gastrointestinal — abdominal pain, nausea, vomiting, diarrhoea
General — chest pain, chest tightness, weakness, malaise, febrile episodes, chills, shivering
Intramuscular injection site — sterile abscess, atrophy/fibrosis, brown skin or underlying tissue discoloration (staining), soreness or pain, swelling, inflammation
Arthralgia and arthritis; leukocytosis and lymphadenopathy; iron overload

Interactions

Drug interactions involving iron dextran have not been studied
Angiotensin-converting enzyme (ACE) inhibitors — concomitant use may increase the risk of anaphylactic-type reactions to an iron dextran product
Laboratory interference — may cause falsely elevated serum bilirubin and falsely decreased serum calcium; large doses (5 mL or more) can give serum a brown colour on samples drawn 4 hours after administration; serum iron determinations (especially colorimetric assays) may not be meaningful for 3 weeks afterwards, and bone marrow examination for iron stores may not be meaningful for prolonged periods
Imaging interference — 99mTc-diphosphonate bone scans have shown a dense crescentic area of activity in the buttocks 1 to 6 days after intramuscular injection, and reduced bony uptake with marked renal activity and excessive blood pool/soft tissue accumulation after infusions

Clinical monograph

How it works

It provides a complex of iron with dextran that is taken up by the reticuloendothelial system, releasing iron for incorporation into haemoglobin and replenishing body iron stores.

Prescribing in practice

Serious hypersensitivity and anaphylactic reactions can occur, so it must be given where resuscitation facilities are available with monitoring during and after administration.
Parenteral iron should not be used in the first trimester of pregnancy and is contraindicated in iron overload or non-iron-deficiency anaemia.
Avoid extravasation, which can cause persistent skin staining at the injection site.

Monitoring

Observe the patient closely for hypersensitivity during and after each dose, and monitor haemoglobin and iron indices to guide replacement.

Counselling the patient

Tell staff immediately if you feel unwell, dizzy, breathless or develop a rash during the infusion.
Some delayed flu-like symptoms or joint aches can occur and usually settle.
You will be observed for a period after the dose as a safety precaution.

Evidence & guidelines

The MHRA advises that all intravenous iron carries a risk of serious hypersensitivity and should be administered with resuscitation facilities available.

Reference: MHRA Drug Safety Update; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

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