Information for patients referred for treatment with ferric derisomaltose at North Bristol NHS Trust.
What is ferric derisomaltose?
Ferric derisomaltose (FDI) is dark brown intravenous iron. It is used to treat iron deficiency – when your body does not have enough iron. It is used when other treatments like tablets aren’t suitable, or if you need treatment quickly. The FDI we use is Pharmacosmos 100mg/ml solution.
Why am I being treated with FDI?
Your healthcare professional has recommended you have treatment with FDI to correct the level of iron in your body.
Why do I need iron?
Iron is important for the formation of red blood cells, and allows red blood cells to carry oxygen around the body. It is also found in enzymes in the body, helps produce proteins in the muscle (myoglobin), and helps the immune system. The human body has around 3-4 grams of iron, and two thirds of this is in red blood cells. You may need to have your iron stores improved for upcoming surgery.
A lack of iron can cause:
- Tiredness.
- Dizziness.
- Irritability.
- Not being able to sleep.
- Dry skin.
- Hair loss.
Before your treatment
You do not need to do anything special to prepare. You can eat and drink as normal – make sure you are well hydrated.
Continue taking all your usual medications but stop any iron tablets at least a day before your appointment.
Wear loose, comfortable clothes and a short-sleeved shirt. You can also bring along a book, or something to watch during and after your treatment.
You will go through your medical history with a member of the team. Please ask them if you have any concerns or questions about your treatment.
How is FDI given?
It is an intravenous treatment, meaning it goes directly into your vein through a drip. A nurse will monitor you.It should not hurt but you may feel a cold sensation in your arm.
How long will it take?
Like all medicines FDI can cause side effects, although not everyone will get them. A member of the team will discuss these side effects with you before starting treatment.
There is a low risk of an allergic reaction. Symptoms include breathing difficulty, dizziness, and swelling in the mouth. You will be monitored closely to make sure you are responding well to the treatment.
Around 1 in 100 people have a Fishbane reaction. This can make you feel flushed. This is not an allergic reaction and is very common. If this happens the infusions can be paused, and continued once the flushing has stopped.
Another uncommon risk is iron leaking and causing a permanent stain to your skin.
Please tell a member of the team if you notice any leaking or have any side effects like flushing, pain, or discomfort. They can stop the treatment if necessary and look after you.
A few days after the treatment you might have a headache, mild fever, or joint pain. These usually go away on their own.
What happens after treatment?
A few weeks or months after treatment you will have a blood test to see if your iron levels are back to where they should be.
Some people may only need one treatment, this depends on whether you have ongoing issues that affect your iron levels.
If you normally take oral iron tablets this will need to be stopped for 7 days after the infusion. Please ask your healthcare professional for more information.
If you become unwell in the days following your iron infusion, please contact your GP surgery or NHS 111. In an emergency phone 999 or go to your nearest Emergency Department.
Further information and references
© North Bristol NHS Trust. This edition published April 2025. Review due April 2028. NBT003783
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