definition of Clozaril - FazaClo (clozapine): This is an antipsychotic medication that may be prescribed off-label for children with autism to help reduce hyperactivity, fidgeting, and aggression. Clozaril® (FazaClo® [orally disintegrating]) lowers binding of dopamine to most types of dopamine receptors and other types of receptors on cells in the nervous system. Clozaril is usually used to treat people with severe schizophrenia, or people who repeatedly threaten to commit suicide. As an uncommon side effect, there is increased risk of seizures or agranulocytosis (a change in white blood cells that can be severe and result in death). The risks are a concern particularly in children and adolescents, and in people who might already have a risk for seizures. The risks also increase with increasing dose of the medication. Other side effects can also occur, including agranulocytosis. People taking Clozaril need to be carefully monitored with regular blood tests for possible side effects.