filgrastim, Neupogen: Drug Facts, Side Effects and Dosage

What is filgrastim (Neupogen), and how does it work (mechanism of action)?

Filgrastim (Neupogen) is a man-made protein that is similar to the naturally occurring protein, granulocyte-colony stimulating factor (G-CSF). G-CSF is produced in the body by the immune system and stimulates the formation of one type of white blood cell, the neutrophil. Neutrophils take part in the inflammatory reaction. They are responsible for detecting and destroying harmful bacteria and some fungi. Filgrastim is produced by bacteria through the use of genetic engineering and recombinant DNA technology. Filgrastim belongs to a class of drugs called colony-stimulating factors because of their ability to stimulate cells in the bone marrow to multiply and form colonies of new cells. Other CSFs include epoetin alfa (Epogen, Procrit) which stimulates the formation of red blood cells and sargramostim (Leukine) which also stimulates the formation of neutrophils. The FDA approved filgrastim in February 1991.

What brand names are available for filgrastim?

Neupogen

Is filgrastim available as a generic drug?

GENERIC AVAILABLE: No

Do I need a prescription for filgrastim?

Yes

What are the uses for filgrastim?

Filgrastim is used to treat neutropenia, a condition in which the body makes too few neutrophils. Neutropenia may be a long-standing condition in which the body does not make enough neutrophils or it may be caused by drugs used to treat cancer. In some cases, the body may make enough neutrophils but, as part of cancer treatment, the doctor may want to increase the number of certain blood cells (CD34 cells) and collect them. The cells are collected using a process called apheresis. These collected cells are given back to the patient after receiving very high doses of treatment for cancer to help the blood counts get back to normal more quickly.

What are the side effects of filgrastim?

The most common side effects are:

Other important side effects include:

Uric acid, lactate dehydrogenase, and alkaline phosphatase levels may rise and spontaneously return to normal levels. Heart attacks and abnormal heart rhythm.

What is the dosage for filgrastim?

The recommended dose is 5 to 10 mcg/kg per day. Filgrastim is administered intravenously or subcutaneously (under the skin) for 6 to 14 days. Filgrastim vials should not be shaken since the drug may be damaged, and bubbles may form that can prevent some of the drug from being drawn up into the syringe at the time of injection.

Which drugs or supplements interact with filgrastim?

Make sure your doctor knows about all medicines, and herbal or vitamin supplements, you are taking before starting filgrastim. If you are taking lithium you may need more frequent blood tests.

If you or your child are receiving filgrastim because you are also receiving chemotherapy, the last dose of filgrastim should be injected at least 24 hours before your next dose of chemotherapy.

Is filgrastim safe to take if I’m pregnant or breastfeeding?

There are no studies to determine if filgrastim is excreted into breast milk.

What else should I know about filgrastim?

What preparations of filgrastim are available?

Filgrastim is available as a liquid for injection in vials or pre-filled syringes containing 300 or 480 micrograms of drug.

How should I keep filgrastim stored?

Filgrastim should be stored at 2 C to 8 C (36 F to 46 F) and should not be frozen.