Explanation

Filgrastim is a man-made version of a protein called a cytokine that is made naturally in your body. Filgrastim helps make more white blood cells in people who don't have enough or need extra.

What does filgrastim do?

Filgrastim tells your bone marrow to make more white blood cells quickly to help your body fight infection. Filgrastim is used in people who are receiving chemotherapy, having a bone marrow transplant, have neutropenia or who have HIV.

What does it look like?

Filgrastim is a clear, colourless liquid for injection. It comes either in a pre-filled syringe that is for injection just under your skin (known as a subcutaneous injection) or in vials for slow injection into one of your veins (known as an intravenous infusion).

When do I have to take it and how much do I use?

Filgrastim is usually given every day. Your doctor will tell you how much you should take depending on why you're being treated with filgrastim and how much you weigh. It's important that you take your filgrastim exactly as your doctor has told you to. You will need to take filgrastim until your white blood cell count is normal. Your doctor will ask you to have regular blood tests to find out how many white blood cells are in your body.

If you're having your filgrastim as an infusion your doctor and nurse will know how much to give you and how often.

How do I take it?

Your doctor or nurse may show you or the adult looking after you how to give the injection so that you can do them at home. It's very important that you don't try to do your own injections if you haven't been shown how to do it properly first. If you can't remember how to do it, or if you're having trouble, call your doctor and ask for help, or ask an adult who is looking after you to help you.

Before you have your injection you should take your syringe out of the refrigerator and either leave it at room temperature for about 30 minutes or hold the pre-filled syringe gently in your hand for a few minutes. It's very important that you don't warm filgrastim in any other way (for example, don't warm it in a microwave or in hot water). It's important that you don't shake the pre-filled syringe or remove the needle cover until you're ready to inject. If you notice a small air bubble in the pre-filled syringe you don't have to remove the air bubble before injecting. Injecting the solution with the air bubble is harmless.

You should remember to do the injections in either:

the front of your thighs, in the middle

your tummy

the back of your upper arms. You should only have your injections in your arms if someone else does it for you.

Remember the needle is meant to go just under your skin, so be very careful not to put it in your muscle. To make it easier you might want to pinch your skin out and inject the skin you're holding.

You should change where you have your injection if you notice the area gets red or sore. Also, don't inject an area where your skin is tender, bruised, red or has scars. You may want to get your parents or the adult looking after you to help you.

It's important that you only use each syringe for one injection. If there is any filgrastim left over in the syringe, don't use it.

But what if I don't feel like taking it?

It's important that you keep taking your filgrastim for as long as your doctor has told you to. If you feel that you don't want to keep taking it for some reason, you should talk to your doctor, but don't just stop taking it!

What should I do if I forget to take it?

Try and take your filgrastim when your doctor has told you to. Even if the adults looking after you forget - go and remind them! If you do forget to take your injection, then don't worry. Just tell an adult looking after you to contact your doctor as soon as possible. It's very important that you don't take a double dose to make up for any missed doses. Remember the three Ds - Don't Double Dose!

What if I take too much?

Make sure that you take the amount of filgrastim that your doctor has told you to. If you think you have injected more than you should, you should tell your doctor as soon as possible.

What are the most likely side effects I might get if I take filgrastim?

When you take filgrastim you may get side effects, although not everybody gets them. It's unlikely but you may have an allergic reaction to filgrastim. If you do, you should stop injecting it and tell your doctor straight away. The signs of this to look out for are:

trouble swallowing or breathing

swelling of your face, throat, hands, or feet

a bad rash, itching, or hives (bumpy patches of red or pale skin that are itchy) anywhere on your body.

You should tell your doctor if you notice any other side effects. These can include:

cough, fever and trouble breathing

pain near the top left of your abdomen or pain at the tip of your shoulder

nausea (feeling sick) and vomiting (being sick)

pain in your bones or muscles

headaches

bleeding or bruising more than normal

feeling tired or weak

not feeling hungry

diarrhoea (runny poo)

pains in your chest

unusual hair loss or thinning

easily broken bones

What other side effects might I get?

The other side effects that can happen after taking filgrastim are very unusual, so you're not likely to get them. Some of these can be serious though, so it's important for you and the adult looking after you to look out for them, just in case.

Tell your doctor or hospital straight away if you notice:

blood in your urine

plum-coloured, raised, painful sores on your arms or legs and sometimes on your face and neck with a fever

coughing up blood

feeling faint

lung infections

pain when you wee

pain and/or swelling in your joints

If any of these side effects get serious, or if you notice any other side effects, you should tell your doctor as soon as possible.

Is it safe for me to be taking filgrastim?

Before you start taking filgrastim you should tell your doctor about any medical problems you know you have, including any allergies, or if you have had any serious problems in the past.

It's especially important that you tell your doctor if you have any of the conditions in this list:

Kostman's Syndrome

sickle cell anaemia

allergy to natural rubber (latex)

myelodysplastic syndrome

leukaemia

Is it OK for me to take filgrastim if I'm already taking other medicines?

Let your doctor know if you're taking, or have recently taken, any other medicines, even herbal medicines or ones you got from the pharmacy without a prescription, as they may affect the way filgrastim works. It's particularly important to tell your doctor if you're taking lithium.

You shouldn't take filgrastim 24 hours before or 24 hours after having chemotherapy, so it's important to tell your doctor if you have had chemotherapy in this time.

Is there anything else I need to know about filgrastim?

Filgrastim contains a sweetener called sorbitol so if you have ever been told that you have a reaction to some sugars you should tell your doctor before you start taking filgrastim.

It's important that you keep your filgrastim in the refrigerator. If you accidentally freeze your filgrastim you can still use it when it defrosts. Don't use filgrastim if you notice that it's cloudy or has particles in it.

When you get older, it's very important if you tell your doctor if you're pregnant or plan to get pregnant as filgrastim could be dangerous for you or your baby.

What if I have any more questions?

If you have any other questions, you can ask your doctor, or chat to other people about Filgrastim in the Medikidz forums and virtual world, Mediland.