White blood cells are a key component of ones immune system. If ones white cell count drops too low, one is much more likely to get an infection. A low white cell count can also lead to neutropenic fever, basically a fever triggered by an abnormally low white cell count.
White blood cells only live for a few weeks in the blood stream. They are continuously being replaced by new white blood cells formed in the bone marrow. Chemotherapy generally attacks all rapidly dividing cells in the body and thus it has the side effect of lowering ones white cell count dramatically because no new white cells are generated for several days after chemotherapy. This effect is one factor that limits the dose of chemotherapy that one can tolerate. The risk of infection is also one of the major risks of chemotherapy. The white cell count drops dramatically for about one week after chemotherapy and then starts to rebound as new white cells are formed after the chemotherapy wears off. Typically, patients have their blood tested prior to each chemotherapy cycle. If white cell counts have not returned to normal, the next chemotherapy dose may be delayed or reduced, which is not a good thing from the point of view of fighting the disease.
Neupogen can be used to stimulate rapid recovery to normal white cell levels, thus ensuring that the risk of infection is minimized and that chemotherapy cycles can proceed normally, without delay or reduction due to low white cell counts.
In Dulce's case, the initial use of Neupogen was to strengthen her immune system so that she could better tolerate an operation to restore a collapsed lung. We then continued with Neupogen during each chemotherapy cycle to keep her as resistant to infection as possible. Normally, Neupogen is recommended to be used for five days, starting five days after chemotherapy is administered. For Dulce, such application caused her white cell counts to rebound from abnormally low to abnormally high. We then shifted to use of only three daily treatments, starting five days after chemotherapy. This ensured that Dulce's white count quickly rebounded and was always normal when it came time for a subsequent chemotherapy treatment. It really only took a small amount of this drug to make a dramatic difference.
Neupogen is administered by intramuscular injection. This can be done by patients themselves as the needles required are basically the same as those used for insulin injection by diabetics. Such needles are available in most pharmacies. And any nurse or doctor can instruct a layperson how to do the injections. The Neupogen vials need to be kept refrigerated. Neupogen is quite expensive and not readily available in most pharmacies, but it can be ordered in. As far as I know, it is only manufactured by Amgen, Inc. In 1998 it was not covered by British Columbia Pharmacare for general use during chemotherapy.
Several precautions are in order if considering Neupogen. Since Neupogen stimulates the bone marrow, it may cause the bone marrow to look abnormal during a bone scan or PET scan. Doctors are aware of this. One risk is that if a bone scan or PET scan show signs of cancer in the bones, then this may be dismissed as being due to the Neupogen. Thus Neupogen increases the likelihood of a false negative indication of bone cancer. Neupogen may also cause bone pain while it is being used. Another precaution is that there has been speculation that Neupogen, which is a simulating factor, might stimulate the cancer itself to spread to the bone marrow. Trials have not shown any indications that this happening, but it is a remote possibility. As in all cancer treatments, there are tradeoffs in risk to be made prior to proceeding with the treatment. I would suggest that all patients undergoing chemotherapy ensure that their doctors consider Neupogen and have it available as an option should neutropenia occur. Kevin...
More information on Neupogen® can be found at the web page of the
manufacturer:
Amgen Inc.
Amgen Center
Thousand Oaks, CA 91320-1789
Tel: (805) 447-1000 Fax: (805) 447-1010
Web: www.amgen.com
Web: www.neupogen.com