Intravenous Iron Pregnancy: Limited data in pregnant women. A careful benefit/risk evaluation is required and Ferinject should not be used during pregnancy unless clearly necessary; iron deficiency in the first trimester can in many cases be treated with oral iron, and treatment should be confined to the second and third trimesters if the benefit outweighs the potential risk. Foetal bradycardia may occur (usually transient, a consequence of maternal hypersensitivity) — monitor the unborn baby carefully during intravenous administration. Breast-feeding: transfer of iron to human milk was negligible (≤1%) and a risk to the breast-fed child is unlikely.

Ferric Carboxymaltose

Brand names: Ferinject

Ferric carboxymaltose is a parenteral (intravenous) iron preparation used to correct iron deficiency, including the iron deficiency anaemia of chronic kidney disease, when oral iron is ineffective or not tolerated.

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 not fixed — it is the individual iron need calculated from body weight and haemoglobin (SPC Table 1). Hb <10 g/dL (<6.2 mmol/L): 30 mg/kg body weight if under 35 kg, 1,500 mg if 35 kg to <70 kg, 2,000 mg if 70 kg and above. Hb 10 to <14 g/dL (6.2 to <8.7 mmol/L): 15 mg/kg if under 35 kg, 1,000 mg if 35 kg to <70 kg, 1,500 mg if 70 kg and above. Hb 14 g/dL and above: 15 mg/kg if under 35 kg, otherwise 500 mg. Two doses may be required to replenish the total iron need.

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

Frequency: Given as one or (if the total iron need is higher) two administrations; a further dose must be a minimum of 7 days after the first. Re-assess Hb no earlier than 4 weeks after the final administration.

Max: Adults and adolescents aged 14 years and older: 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. In haemodialysis-dependent chronic kidney disease a single maximum daily dose of 200 mg iron must not be exceeded.

Source: UK SPC (eMC) for Ferinject 50 mg iron/mL dispersion for injection/infusion, §4.2 (https://www.medicines.org.uk/emc/product/5910/smpc). Iron deficiency must be confirmed by laboratory tests. POSOLOGY IS A 3-STEP PROCESS: [1] determine the individual iron need (Table 1, above); [2] calculate and administer the dose(s) within the maximum single/cumulative limits; [3] post-repletion re-assessment by the clinician, with Hb re-checked no earlier than 4 weeks after the final dose; if further repletion is needed the iron need must be recalculated. ADMINISTRATION RATES — intravenous injection: 2 to 4 mL (100 to 200 mg) 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 up to 50 mL, no minimum time; >4 to 10 mL (>200 to 500 mg) in up to 100 mL over at least 6 minutes; >10 to 20 mL (>500 to 1,000 mg) in up to 250 mL over at least 15 minutes. For stability reasons do not dilute to 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 are assured; observe the patient for at least 30 minutes after each administration. Monitor serum phosphate in patients receiving multiple or higher doses or long-term treatment, and in those with existing risk factors for hypophosphataemia. PAEDIATRIC (limits quoted from §4.2, not converted into a dosing rule here): 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), and the maximum recommended cumulative dose is 750 mg of iron per week, with any additional dose a minimum of 7 days apart; not recommended in children below 1 year of age (efficacy and safety not investigated); not recommended in children aged 1 to 13 years with chronic kidney disease requiring haemodialysis (efficacy and safety not investigated). Verify any under-18 use against a children's formulary. §4.5 interactions was not retrieved in this bundle — verify separately. §4.4 and §4.8 were truncated at the source-fetch limit.

Dose adjustments

Renal

Haemodialysis-dependent chronic kidney disease (adults and adolescents aged 14 years and older): a single maximum daily dose of 200 mg iron must not be exceeded; no safety data are available for single doses of more than 200 mg iron in this population. May be given undiluted directly into the venous limb of the dialyser during a haemodialysis session. Not recommended in children aged 1 to 13 years with chronic kidney disease requiring haemodialysis. Careful monitoring of iron status is recommended to avoid iron overload.

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 Ferinject 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 (3.2% of subjects)
Injection/infusion site reactions (pain, haematoma, discolouration, extravasation, irritation)
Hypophosphataemia (common); symptomatic hypophosphataemia leading to osteomalacia and fractures requiring intervention reported post-marketing
Headache, dizziness (common); flushing and hypertension (common), hypotension uncommon
Hypersensitivity (uncommon) and anaphylactic reactions (rare, fatalities reported) — the most serious reaction; Kounis syndrome reported post-marketing
Rash, pruritus, urticaria, erythema; arthralgia, myalgia, back pain, muscle spasms; raised ALT/AST/GGT/ALP/LDH

Clinical monograph

How it works

It delivers a stable iron-carbohydrate complex that is taken up by the reticuloendothelial system and released to transferrin, replenishing iron stores for erythropoiesis.

Prescribing in practice

Administer only where facilities to manage anaphylaxis are immediately available and observe the patient during and after the infusion, as serious hypersensitivity reactions can occur.
It commonly causes a transient, usually asymptomatic hypophosphataemia that can be clinically significant with repeated dosing.
Avoid in the first trimester of pregnancy and use later only if clearly necessary, per the SPC.

Monitoring

Monitor iron indices and haemoglobin response, and check serum phosphate with repeated or high cumulative dosing.

Counselling the patient

Tell staff immediately of any rash, breathlessness, dizziness or facial swelling during the infusion.
Skin staining can occur if the drug leaks at the cannula site, so report any pain or burning there.
A blood test to check phosphate may be needed after treatment.

Evidence & guidelines

MHRA guidance reinforces resuscitation readiness for all IV iron and recognises hypophosphataemia as an established class effect.

Reference: FAIR-HF Trial (Anker et al, NEJM 2009); NICE NG203; Ferinject SPC; 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.

Calculators

Drugs

Iron Sucrose (Venofer) 100–200mg IV · Intravenous Iron

Pathways