Filgrastim (injection)

Chemotherapy patients and patients with compromised immune systems often have low white blood cell counts, and this deficiency can be made up for by filgrastim.


Filgrastim is an artificially made substance which mimics a substance made naturally in the body, and helps to make up for a deficiency of white blood cells. Since white blood cells are used to fight off disease and other harmful attacks against the body, it is important that white blood cell counts be maintained. Many people experience a reduction of white blood cells when undergoing chemotherapy, chronic neutropenia, or exposure to unusually high levels of radiation.

This medication is normally delivered to a patient via injection, either under the skin or directly into a vein, and the amount injected will depend on exactly what condition a patient is being treated for, as well as the patient's physical characteristics.

Filgrastim is a protein which is manufactured to imitate a naturally-occurring protein in the body, that of granulite-colony stimulating factor (G-CSF). This protein is capable of stimulating the production of neutrophil, which is a particular type of white blood cell, which identifies and destroys harmful bacteria that causes inflammation in the body.

This drug belongs to the class of drugs known as colony stimulating factors, because of its ability to stimulate the growth of new colonies of cells for fighting bacteria. It is made by combining recombinant DNA technology with that of genetic engineering to produce an artificial protein which is just as effective as the one produced by the body itself.

Condition Treated

  • Stem cell transplant, bone marrow transplant, post-chemotherapy (low white cell count in the blood)

Type Of Medicine

  • Man-made protein ' colony stimulating factors

Side Effects

Although it provides some very useful benefits and advantages to patients, some will experience side effects that range in severity from mild to moderate or worse. If you should experience any side effects as a result of taking filgrastim, you should report them to your doctor as soon as possible, and if they are serious enough to require medical treatment, he/she will know how to handle that. Some of the most common side effects associated with taking this medication are:

  • Stomach pain or abdominal pain
  • Nausea and/or vomiting
  • Lower back pain or side pain
  • Red spots on the skin or purple spots on the skin
  • Difficulty with breathing
  • Coughing up blood
  • Bleeding gums
  • Sensation of being bloated or full
  • Swelling in the facial area
  • Fever and or chills
  • Unexplained bleeding or bruising
  • White spots, sores, or ulcers which appear inside the mouth or on the lips and tongue
  • Difficulty with swallowing
  • Sore throat
  • Persistent headaches
  • Nosebleeds with no apparent cause
  • Pain which radiates up to the shoulders
  • Unusual paleness of the skin
  • Prolonged bleeding from cuts
  • Stools which are tarry, red, or black in color
  • Skin rashes or hives
  • Urine which is dark brown in color or red
  • Tightness of the chest
  • Difficulty breathing after even mild exertion
  • Abnormally heavy menstrual flow or other vaginal bleeding
  • Persistent and heavy diarrhea
  • Temporary paralysis
  • A wide variety of manifestations at the injection site, including itching, hives, infection, a sensation of pressure, skin discoloration, coldness, burning or stinging, ulceration, swelling, numbness, tenderness, soreness, scarring, unusual warmth, and even bleeding.

There are also a number of side effects which occur less frequently in patients, but which are listed below because they have been reported as a result of using filgrastim:

  • Blurry vision or other vision problems
  • Chest pains
  • Slow, fast, or irregular heartbeat
  • Loss of appetite and weight loss
  • Pain in the bones, muscles, or joints
  • Thinning hair or loss of hair
  • A pounding noise in the ears
  • Nervousness and irritability
  • Blisters on the skin
  • Blue color in the fingernails, skin, or lips
  • Abnormal difficulty with bowel movements
  • Shallow, fast breathing
  • Unexplained sores appearing on the skin surface of the body
  • Swelling or inflammation in the area around the mouth.


A typical dosage for an adult using filgrastim would be 5 to 10 µg per kilogram of weight on a daily basis, for a time period lasting between six days and two weeks. The drug should be administered subcutaneously or intravenously, ideally in a clinical setting, but it can also be administered at home if the patient has been properly instructed about delivery methods. The vials of filgrastim should never be shaken, because this can damage the medication itself, and it may also cause bubbles to form, which prevent the medication being drawn up into a syringe when it is time to administer a dosage.

The dosage listed above is only to be understood as a standard dosage, and not one that is appropriate for you personally. Your specific dosage will depend on a number of factors, including the specific reason you are being treated, your medical condition at the time of treatment, results from laboratory tests, your physical weight, and your body's reaction to treatment, as well as tolerance of the medication.

If you are administering filgrastim to yourself at home, you need to be well-versed in all the preparation and usage procedures before you attempt to put them into practice. Normally your doctor will thoroughly instruct you at the office before allowing you to self-administer at home. Before you inject the medication, it should be taken out of the refrigerator at least a half hour prior to your scheduled dosage time, so that it has a chance to warm up to room temperature and be close to your body's temperature.

Before injecting the medication, make sure to visually inspect the solution in the vial for any particles that might be present or any discoloration, as described by your doctor. If you should identify either discoloration or the presence of particles, do not use the medication, and you should instead seek a replacement vial.

Before you inject the medication, make sure to have cleaned and sterilized the injection site with rubbing alcohol so that you don't introduce any germs into the body. You should also change up your injection sites so as not to injure one specific area of the body, or to increase the likelihood of injection side effects.

You should never inject filgrastim into locations on the skin which are bruised or tender, or which have scars or stretch marks. In order to get the maximum benefit from filgrastim, you should administer it at home at the same time each day, so that your body can become acclimated to it, and so that you remember to do it each day. If you are a patient undergoing chemotherapy, filgrastim should not be administered in the 24-hour period prior to your chemotherapy session, nor during the 24 hour period following a session.


There is a potential for filgrastim to interact with other medications which you may be taking, so it's important that your doctor have a full understanding of all of these other medications, as well as their dosages, so that any adverse reactions can be avoided. It's also possible that interactions between filgrastim and other medications don't necessarily cause side effect problems, but one or the other can be reduced in effectiveness by coming into contact with another medication.

For this reason, it would be very helpful for you to prepare a list of all medications that you are currently taking, including herbal supplements, vitamins, over-the-counter drugs, and any other prescription medications as well. Your doctor can review this list and make a determination about whether some medications should be discontinued while you are using filgrastim, or whether dosages must be reduced so as to avoid unwanted side effects. You can also use this list when you need to go to an emergency room or healthcare clinic where your primary care doctor is not in residence. Any doctor can review this list and avoid drug interactions by prescribing medications to treat your condition which will not impact your usage of other drugs you are using.

Patients who have a medical history of myeloid tumors, leukocytosis, or glomerulonephritis, should not concurrently take filgrastim, because these medical conditions are known to be impacted by the drug.

In terms of other drugs which are known to have some type of interaction with filgrastim, those listed below are the ones most commonly checked by doctors:

  • Vitamin B complex 100
  • Vitamin D3
  • Senna Lax
  • Prograf
  • Aloprim
  • Aspirin low strength
  • Lasix
  • Imdur
  • Demerol
  • Hydromorphone
  • Sulfamethoxazole
  • Mycophenolate mofetil
  • Bactrim
  • Potassium chloride
  • Plavix
  • Nexium
  • Acetaminophen
  • Neurontin.

It is also possible for filgrastim to interact with certain laboratory tests such as those for imaging of bones, so if you are scheduled to take any such tests, it is advisable to alert your doctor and all lab personnel to the fact that you are being treated with filgrastim. Your doctor will probably recommend that you discontinue usage of this medication if it is necessary to arrange lab tests for you which may be affected by the drug.


When you are in a program of treatment which includes filgrastim, there are some precautions which you should observe and be aware of, so as not to worsen any medical condition you have, or to introduce any new ones because of your medical profile.

If you know that you are allergic to filgrastim solution, you should point this out to your doctor right away in an initial consultation, so that you do not induce an allergic reaction when taking the drug. If you have any other allergies such as to pets, foods, food preservatives, or fabrics, make sure to inform your doctor of these as well, since certain ingredients within filgrastim may trigger those other allergies.

Your doctor will want to have a full review of your medical history prior to prescribing filgrastim, and you should especially point out any history of sickle cell disease, any radiation treatment you may have previously undergone, or any spleen problems which you have had before.

There may be a significant risk posed to pregnant women who take filgrastim, so you should have a thorough consultation with your family doctor if you are currently pregnant, or thinking of becoming pregnant while also being treated with this drug. Extensive studies conducted on animal populations have shown that there is an increased instance of embryo lethality and a potential for spontaneous abortions.

When these studies were conducted, the dosage level used was nearly 4 times what is commonly prescribed for a human patient, but it should be borne in mind that filgrastim still may have the potential to harm an unborn fetus. Since it cannot be known exactly what the correlation is between animal tolerance of the medication and human tolerance, it must be assumed that any amount of the medication could potentially trigger undesirable results in a fetus.

Also in these animal studies, it was found that some fetuses were subject to below normal birth weights and later experienced developmental difficulties. Since there are a number of demonstrated harmful effects in animal studies, and there are no corresponding studies which have been conducted on human populations, the safest course of action is to avoid taking filgrastim during pregnancy.

Mothers who wish to breastfeed should consult with their doctors about the advisability of their particular cases. It is known that the protein granulocyte colony-stimulating factor (filgrastim) is naturally included in breast milk, as part of the body's normal production of the protein. However, it is not known whether the artificial version of this protein is passed on through breast milk to a nursing infant, nor is it known whether artificial filgrastim would have any impact on an infant.

The likelihood is that there would be no problems associated with a mother breastfeeding an infant while being treated with filgrastim, but the matter should be discussed with the family doctor in individual cases.


Filgrastim should be stored at home in a refrigerated setting, between 36 degrees Fahrenheit and 46 degrees Fahrenheit, and should never be frozen. Before it is injected, it must be warmed up for at least 30 minutes at room temperature, because it will need to be close to the body's regular temperature to avoid any kind of reaction.

Patients who self-administer at home must be very careful to keep this medication out of the reach of children who might access the refrigerator and be curious about the medicine. If possible, a separate mini-refrigerator should be used with some kind of locking mechanism to prevent unintended access.

If you should need to dispose of unused filgrastim, do not simply flush it down a sink or toilet, but follow the recommendations of your doctor or pharmacist. You can also consult a website which is maintained by the FDA, and supplies relevant information on the safe disposal of medicines.


Figrastim is a man-made protein of the type granulite colony stimulating factor, and it mimics a protein made by the body itself. When the body has a deficiency of white blood cells, this medication can be used to stimulate greater production of them, so they will fight inflammation, infection, and other harmful medical conditions in the body.

This medicine is commonly used during or after treatment for a bone marrow transplant, a stem cell transplant, and during chemotherapy treatment. Since the radiation has a tendency to harm or kill off white blood cells, a deficiency is created in the body, and this can leave the body vulnerable to all manner of diseases and other undesirable reactions. Filgrastim can be very effective at stimulating new growth of white blood cells to help counteract this situation.

The normal route of delivery for filgrastim would be via injection, either into a vein or just below the skin, and while a skilled medical professional would most commonly do this, it can be done in the home setting as well. Before attempting to self-administer, you should receive thorough instruction from your doctor or nurse, so that you are familiar with the delivery procedure, as well as the care and usage of all materials, including syringes.