Monofer (Ferric Derisomaltose) — NZ Medication Guide | KiwiMeds
✅ Reviewed by Ramon Wong, BPharm, Registered Pharmacist (New Zealand) | May 2026 — This information is for educational purposes only and is not a substitute for personalised advice from your doctor or pharmacist. Always seek professional guidance before making changes to your medications.
What is Monofer (ferric derisomaltose)?
Monofer (generic name: ferric derisomaltose, also known as iron isomaltoside) is an intravenous (IV) iron preparation — an iron replacement treatment given directly into a vein via an infusion (drip) at a hospital or clinic. It is used to treat iron deficiency anaemia when other iron treatments are not suitable or have caused serious reactions.
What is it used for? (NZ context)
In New Zealand, ferric derisomaltose (Monofer) is funded by Pharmac from 1 March 2026 in hospitals for people who have experienced a serious reaction to other funded iron infusions.
This includes people who have experienced:
- Hypophosphataemia (dangerously low phosphate levels in the blood) after other iron infusions — a rare but serious side effect of some iron formulations
- Serious adverse reactions (hypersensitivity/anaphylaxis-type reactions) to other funded IV iron products
Around 100 people are expected to benefit annually. See the Pharmac announcement.
How does it work?
Ferric derisomaltose provides iron in a form that the body can safely take up and use. The iron is bound to a carbohydrate carrier (derisomaltose/isomaltoside), which stabilises it and allows it to be given as a rapid IV infusion without the instability problems seen with some older iron preparations. Once in the bloodstream, the iron is released slowly from the carrier and taken up by cells throughout the body — primarily to make haemoglobin in red blood cells. Haemoglobin is the protein in red blood cells that carries oxygen around the body. Iron deficiency means not enough haemoglobin can be made, causing anaemia (low red blood cell count) and symptoms like fatigue, shortness of breath, and pallor. Ferric derisomaltose restores the body’s iron stores and allows red blood cell production to recover.
An advantage of ferric derisomaltose is that it has a lower risk of causing hypophosphataemia compared to some other IV iron formulations (particularly ferric carboxymaltose), making it a suitable alternative for patients who have experienced this complication.
How to take it
Monofer is given as an IV infusion (drip) at a hospital — it is not a take-home medicine. It is administered directly into a vein through a cannula (small plastic tube).
Key points:
- Can be given as a single large dose (up to 20 mg/kg of body weight) over approximately 20–60 minutes, rather than needing multiple visits like some other IV iron products
- The dose is calculated based on your body weight and how iron-deficient you are (your haemoglobin and ferritin blood tests)
- You will be monitored during and for a short period after the infusion
Common side effects
Ferric derisomaltose (Monofer) is generally well tolerated. Common side effects include:
- Nausea
- Headache
- Flushing
- Dizziness
- Injection site reactions (bruising, pain, or discolouration at the IV site)
- Temporary rise in blood pressure during the infusion
Serious side effects to watch for
Serious but rare side effects include:
- Hypersensitivity/anaphylactic reactions — symptoms during or shortly after the infusion include itching, rash, hives, swelling of the face or throat, difficulty breathing, chest pain, or collapse. This is why you are monitored during and after the infusion and why all IV iron is given in a hospital setting where treatment for reactions is immediately available
- Hypotension (low blood pressure) during the infusion
- Iron overload — if you receive too much iron over time (rare; your iron levels will be monitored)
Important drug interactions
IV iron should generally not be given at the same time as:
- Oral iron supplements — taking oral iron reduces the effectiveness of IV iron (and is unnecessary if getting IV iron)
- There are few other significant drug-drug interactions for IV ferric derisomaltose
Things to avoid while taking it
- Do not take oral iron tablets/supplements for at least 5 days before and after your Monofer infusion — oral iron competes with the IV iron for uptake
- Driving or operating heavy machinery immediately after the infusion if you feel dizzy — wait until you feel well
NZ-specific information
Brand name in NZ: Monofer
Also known as: Iron isomaltoside, ferric isomaltoside
Funded: Yes — from 1 March 2026 in hospitals for people who have experienced serious reactions to other funded IV iron infusions
How it is given: IV infusion at hospital (not take-home)
Standard funded IV iron in NZ: Ferric carboxymaltose (Ferinject) is the first-line funded IV iron; Monofer is the alternative for those who react to it or develop hypophosphataemia
Special Authority: Your doctor will manage eligibility
Ferric derisomaltose has a lower risk of causing hypophosphataemia than ferric carboxymaltose, which makes it the better choice for the specific group of patients who experience this complication. The funding was also triggered by the discontinuation of Venofer (iron as sucrose), which was previously used for this patient group.
Frequently asked questions
Why can’t I just take iron tablets?
Oral iron tablets are the first choice for most people with iron deficiency, but some people cannot absorb them properly (e.g., inflammatory bowel disease, coeliac disease, after bariatric surgery) or cannot tolerate the gastrointestinal side effects. Pregnant women with severe anaemia may also need IV iron for faster replenishment.
Why is Monofer only for people who reacted to other IV iron?
Monofer is more expensive than the standard funded IV iron (Ferinject). Pharmac funds it specifically as an alternative for the smaller group of patients who cannot safely use standard options. Most patients with iron deficiency needing IV iron will receive Ferinject first.
Will I need more than one infusion?
Monofer can often be given as a single full dose, which is an advantage. Your doctor will calculate the dose and decide if one infusion is enough based on your blood tests.
When will I feel better?
Most people notice improvement in energy and other anaemia symptoms within 1–2 weeks of the infusion. Full replenishment of iron stores takes about 4–8 weeks.
Related medications
- Ferric carboxymaltose (Ferinject) — standard first-line funded IV iron in NZ
- Oral iron supplements (ferrous sulfate, ferrous fumarate) — first-line treatment for mild-moderate iron deficiency