A low white blood cell count, also known as neutropenia is one of the most serious and frequent side effects of chemotherapy. It can necessitate a delay in treatment or a reduction in the dose. White blood cells are necessary for the body to fight infection, so when they are low, a person is more susceptible to infections. Patients with low white blood cell counts should avoid people with colds or crowded areas, wash their hands frequently, and be sure all food is clean and cooked. There are several medications, called colony-stimulating factors, which can prevent the white blood cell count from dropping or help it recover faster. These medications (filgrastin, sargramostim) are given by an injection subcutaneously. They are most effective when started the day after chemotherapy to prevent the white blood cell count from dropping too low. Regards Dr De