Is there a way to prevent white blood cell count from dropping?

Yes, if the doctor determines you or the person you're caring for is at risk for losing too many white blood cells, she can prescribe a white blood cell booster, more formally known as a colony stimulating factor, or CSF. These popular drugs are called filgrastim and pegfilgrastim -- or Neupogen and Neulasta, their brand names. It's common tol begin taking the drugs at the start of chemotherapy, in the hope that they'll boost white cell production and strengthen the body's natural defense system. The doctor can also prescribe them later to try to bring the white count up if it doesn't rise fast enough on its own.