IV iron Pregnancy: Limited data in pregnant women. A careful benefit/risk evaluation is required and the product should not be used during pregnancy unless clearly necessary. Iron deficiency in the first trimester can in many cases be treated with oral iron; treatment should be confined to the second and third trimester if the benefit outweighs the potential risk to mother and foetus. Foetal bradycardia may occur following parenteral iron (usually transient, secondary to maternal hypersensitivity) — monitor the unborn baby carefully during administration. Transfer of iron into human milk is negligible (1% or less) and it is unlikely to represent a risk to the breast-fed child.

Ferric carboxymaltose

Brand names: Ferinject

Ferric carboxymaltose is a parenteral iron preparation used to treat iron-deficiency anaemia when oral iron is ineffective, not tolerated, or rapid replenishment is needed.

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: Dose is the individually calculated total iron need, based on body weight and haemoglobin (SPC Table 1). Adults and adolescents 14 years and over — 70 kg and above: 2,000 mg iron if Hb <10 g/dL, 1,500 mg if Hb 10 to <14 g/dL, 500 mg if Hb 14 g/dL or above. 35 kg to <70 kg: 1,500 mg iron if Hb <10 g/dL, 1,000 mg if Hb 10 to <14 g/dL, 500 mg if Hb 14 g/dL or above. Below 35 kg: 30 mg/kg body weight if Hb <10 g/dL, 15 mg/kg if Hb 10 g/dL or above. The total iron need is given as one or two administrations, each capped as under maxDose.

Route: Intravenous only — by slow injection using undiluted dispersion, by infusion after dilution in sterile 0.9% sodium chloride only, or undiluted directly into the venous limb of the dialyser during a haemodialysis session. Must NOT be given by the subcutaneous or intramuscular route.

Frequency: One or two administrations per repletion course; if the total iron need exceeds the maximum single dose, give the additional dose a minimum of 7 days after the first. Re-assess Hb no earlier than 4 weeks after the final administration and recalculate the iron need if further repletion is required.

Max: Adults and adolescents 14 years and over: a single administration must not exceed 15 mg iron/kg body weight (intravenous injection) or 20 mg iron/kg body weight (intravenous infusion), and must not exceed 1,000 mg of iron (20 mL). Maximum recommended cumulative dose 1,000 mg of iron per week. Haemodialysis-dependent chronic kidney disease: single maximum daily dose of 200 mg iron must not be exceeded.

SOURCE PRODUCT: Ferinject 50 mg iron/mL dispersion for injection/infusion (UK SPC). ADMINISTRATION RATES — intravenous injection: 2 to 4 mL (100 to 200 mg iron) no minimum prescribed time; >4 to 10 mL (>200 to 500 mg) at 100 mg iron/min; >10 to 20 mL (>500 to 1,000 mg) over 15 minutes. DILUTION FOR INFUSION (0.9% sodium chloride only): 2 to 4 mL (100 to 200 mg) in max 50 mL, no minimum time; >4 to 10 mL (>200 to 500 mg) in max 100 mL over at least 6 minutes; >10 to 20 mL (>500 to 1,000 mg) in max 250 mL over at least 15 minutes. For stability reasons do not dilute to concentrations less than 2 mg iron/mL. MONITORING: administer only where staff trained to evaluate and manage anaphylactic reactions are immediately available and full resuscitation facilities can be assured; observe the patient for adverse effects for at least 30 minutes after each administration. Serum phosphate should be monitored in patients receiving multiple administrations at higher doses or long-term treatment, and in those with existing risk factors for hypophosphataemia; symptomatic hypophosphataemia leading to osteomalacia and fractures has been reported post-marketing. Iron deficiency must be confirmed by laboratory tests. HEPATIC: in liver dysfunction give parenteral iron only after careful benefit/risk assessment; avoid where iron overload is a precipitating factor, in particular porphyria cutanea tarda. INFECTION: use with caution in acute or chronic infection, asthma, eczema or atopic allergy; stop treatment in patients with ongoing bacteraemia. PAEDIATRIC (no single clean per-kg dose — not structured): children and adolescents aged 1 to 13 years — a single administration must not exceed 15 mg iron/kg body weight or 750 mg of iron (15 mL), with a maximum recommended cumulative dose of 750 mg of iron per week and any additional dose at least 7 days apart. The total iron need is still determined from SPC Table 1 (patients below 35 kg: 30 mg/kg if Hb <10 g/dL, 15 mg/kg if Hb 10 g/dL or above), so the per-kg figure is a calculation input plus a cap rather than a single stated dose. Not recommended in children below 1 year of age (efficacy and safety not investigated), and not recommended in children aged 1 to 13 years with chronic kidney disease requiring haemodialysis. Verify any paediatric use against a children's formulary. US CROSS-CHECK ONLY (Injectafer, do not substitute for the UK regimen): 50 kg or more — 750 mg IV in two doses at least 7 days apart (cumulative 1,500 mg per course), or in adults 15 mg/kg up to a maximum 1,000 mg as a single dose per course; under 50 kg — 15 mg/kg in two doses at least 7 days apart.

Dose adjustments

Renal

In adults and adolescents aged 14 years and over with haemodialysis-dependent chronic kidney disease, a single maximum daily dose of 200 mg iron must not be exceeded; no safety data are available for single doses above 200 mg iron in these patients. Not recommended in children aged 1 to 13 years with chronic kidney disease requiring haemodialysis (efficacy and safety not investigated).

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; 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

Hypersensitivity to the active substance, to the product or to any of its excipients
Known serious hypersensitivity to other parenteral iron products
Anaemia not attributed to iron deficiency, e.g. other microcytic anaemia
Evidence of iron overload or disturbances in the utilisation of iron

Side effects

Nausea — the most commonly reported reaction, occurring in 3.2% of subjects
Injection/infusion site reactions (pain, haematoma, discolouration, extravasation, irritation, paraesthesia)
Hypophosphataemia; hypophosphataemic osteomalacia has been reported post-marketing
Headache, dizziness
Flushing and hypertension. The most serious reaction is anaphylactic reaction (rare) — fatalities have been reported; hypersensitivity reactions progressing to Kounis syndrome have also been reported

Clinical monograph

How it works

It is a stable iron-carbohydrate complex that delivers iron to the reticuloendothelial system, from where it is incorporated into ferritin stores and used for haemoglobin synthesis.

Prescribing in practice

Serious hypersensitivity and anaphylaxis can occur, so it must be given where resuscitation facilities are available, with observation after administration, and it should generally be avoided in the first trimester of pregnancy.
It can cause clinically significant and sometimes persistent hypophosphataemia, particularly with repeated dosing, so phosphate should be checked in at-risk or repeatedly treated patients.
Extravasation can cause long-lasting brown skin staining, so careful intravenous administration is essential and it should not be given during active infection.

Monitoring

Monitor for hypersensitivity during and after infusion, reassess haemoglobin and iron indices after a suitable interval, and check serum phosphate with repeated or high-dose courses.

Counselling the patient

Report any rash, wheeze, swelling or dizziness during or shortly after the infusion at once.
Tell the nurse immediately if you feel burning or see swelling at the drip site, as leakage can stain the skin.
Report persistent tiredness, bone pain or muscle weakness after treatment, which can signal low phosphate.

Evidence & guidelines

Intravenous iron such as ferric carboxymaltose is supported by NICE guidance for iron-deficiency anaemia, with MHRA advice on hypersensitivity precautions and the risk of hypophosphataemia.

Reference: NICE NG8; 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).

Curated clinical cross-links plus same-class fallbacks.

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