Clozapine is an antipsychotic drug used to treat schizophrenia in patients whose symptoms are not controlled with standard antipsychotic drugs. Clozapine is also used in patients with recurrent suicidal behavior associated with schizophrenia or schizoaffective disorder. While clozapine benefits some patients, there are risks associated with this drug. Specifically, clozapine can decrease the number of neutrophils, a type of white blood cell that functions in the body to fight off infections. When neutrophils are significantly decreased, severe neutropenia may result, and the body may become prone to infections. For this reason, patients taking clozapine need to have their absolute neutrophil count (ANC) monitored on a regular basis.