procrit raises the red blood count while neupogen raises the white count.
a low red count usually results in fatigue, low white count results in an inability to fight off infections such as a cold or flu.
Both are serious, especially a low white count. If he has a low white count, call any doctor or nurse at any hour of the day with the first sign of a cold or -any- kind of infection. Infections can become septic overnight...
It's likely its from the treatment, but it also can depend on the cancer and it's effect.
Best to call the doctor to make sure.