Understanding Filgrastim

Your doctor has prescribed the medicine filgrastim. This medicine is a human-made version of a protein called granulocyte colony-stimulating factor (G-CSF). Your body makes G-CSF to tell the bone marrow to make more white blood cells.

Filgrastim is not a cancer treatment. It's a supportive therapy. G-CSF is a type of myeloid growth factor, used to raise the number of neutrophils in your blood. A neutrophil is a type of infection-fighting white blood cell. You may be getting this medicine because your last chemotherapy (chemo) treatment caused your neutrophil count (ANC, or absolute neutrophil count) to drop. In some cases, radiation therapy to specific bones can also cause the neutrophil count to drop. Filgrastim may also be used before stem cell transplants to help stimulate the bone marrow to produce more normal stem cells to be collected before you have high-dose chemotherapy. Your ANC is measured with blood tests.

Filgrastim costs a lot of money. Talk with your doctor to find out if your insurance will pay for it and how much you would need to pay. There are many different brands of filgrastim. You may need to get the brand your insurance covers.

Filgrastim is given as a shot (subcutaneous injection) or sometimes as an intravenous (I.V.) infusion. It is given in a doctor's office, clinic, or infusion suite, or at home, depending on your insurance coverage. Your doctor or pharmacist can give you more information about it.

This sheet will also help you learn more about filgrastim.

This medicine can:

• Make you less likely to get an infection.
• Make it safer for you to be around other people, so you can do more.
• Help prevent illness that could cause a delay or change in your treatment.

Certain kinds of chemo reduce the number of neutrophils in your blood. As the number of these cells goes down, you are less able to fight infection. Filgrastim helps your bone marrow make these blood cells and push them out into your blood faster.

About 24 hours after chemo, you'll get your first filgrastim shot. You'll get a shot every day until your blood counts reach a certain level. Talk with your doctor about this level and how long you may need to receive filgrastim. You may also get a long-acting version of filgrastim that requires a single shot instead of multiple shots.

The most common side effects are:

• Bone, joint, and muscle pain.
• A mild fever.
• Redness, swelling, or itching where the shot is given.

These symptoms can often be eased with a heating pad and certain medicines. Check with your doctor before you take any medicine to help with side effects from filgrastim. Antihistamine pills such as loratadine (for example, Claritin) can reduce bone pain caused by these shots.

Other rare side effects include:

• Headache.
• Pain in the lower back or pelvis.
• Skin rash or itching.
• Tiredness.
• Cough.
• Shortness of breath.
• Dizziness.
• Nausea.
• Chest pain.
• Rupture of the spleen (very rare).

Tell your doctor about any changes you notice. They can tell you what to do to manage or even prevent treatment side effects.

Contact your doctor right away if:

• You have symptoms of infection, such as:
  • A fever.
  • Chills.
  • A sore throat.
  • A new cough.
  • Diarrhea.
  • Redness at the site of a wound or sore.
  • Burning when passing urine or changes in how your urine looks or smells.
• You have pain in your left upper stomach or left shoulder area. (This could be a symptom of an enlarged spleen, which is a rare side effect of this treatment.)
• You bruise or bleed easily.
• You have shortness of breath, wheezing, dizziness, swelling around the mouth or eyes, a fast pulse, or sweating.
• You have redness, swelling, or itching at the site of the shot.

Talk with your doctor about what symptoms to watch for and when to contact them. Know what number to call with questions or problems. Is there a different number to call for evenings, weekends, or holidays?