Neutropenia is common among people with HIV, often the result of bone marrow toxicity caused by drugs used to treat HIV infection. Before the development of colony-stimulating factors, people would have to stop using drugs with bone marrow toxicity when their neutrophil counts dropped to dangerously low levels. In addition, drugs such as AZT and ganciclovir frequently couldn't be used together because their toxicity to the bone marrow was additive. Now it is common to use these and other drugs in combination with G-CSF, to prevent or reverse low neutrophil counts. Drugs that can cause bone marrow toxicity usually also reduce the number of platelets circulating in the blood, a condition called thrombocytopenia.
Platelets are particles involved in the blood clotting process.
When their numbers are reduced, people have a tendency to bruise easily and heal slowly. Blood clotting is less efficient and bleeding times are extended. G-CSF is not effective in increasing platelet count. G-CSF is available as a solution for injection. It may be injected in the physician's office or at home by the patient.