Clozapine is sold under the brand name "Clozaril".
Clozapine was the first atypical antipsychotic. It is FDA approved for the treatment of refractory Schizophrenia and for the reduction of recurrent suicidal behavior in Schizophrenia and Schizoaffective Disorder.
Clozapine can cause serious and potentially life threatening side effects. It is allowed to remain on world markets because it has been shown in many clinical trials to be effective in up to one third of cases of otherwise treatment refractory Schizophrenia. It is also felt by many experts to be the most effective treatment for Bipolar Disorder available.
Clozapine has complex mechanisms of action that include blockade of dopamine and serotonin receptors for its therapeutic benefits. Blockade of histamine and acetylcholine receptions account for most of its adverse effects. The atypical antipsychotics as a group are distinguished by blockade of postsynaptic serotonin 2A receptors which confers relative protection against many of the serious adverse effects (e.g. tardive dyskinesia, akathisia and dystonic reactions) of the first generation, or typical, antipsychotics (e.g. haloperidal (Haldol), perphenazine (Trilafon), chlorpromazine (Thorazine), and others).
Clozapine is processed for elimination from the body (“metabolized”) in the liver to inactive compounds that are in turn eliminated by the kidneys. The half life of clozapine is significantly less than one day and consequently if stopped abruptly (not recommended) it is eliminated form the body in about 3 days.
Possible adverse effects can include agranulocytosis (potentially fatal), diabetes, seizures, sweating, increased salivation, weight gain, abnormal triglycerides and cholesterol, insulin resistance, sedation, dizziness, dry mouth, constipation, and others. This is data that suggest this category of medication can rarely cause strokes in the elderly.
Clozapine, along with the other atypical antipsychotics, carries a warning from the FDA against the possibility of new onset diabetes mellitus. Guidelines for the appropriate medical monitoring of this category of medications for these possible medical adverse events were published in 2003. We follow these guidelines at Scott P. Hoopes, M.D., & Associates. It you are prescribed clozapine you will be referred to our Metabolic Clinic for medical monitoring. Following these guidelines is essential for the responsible use of all the atypical antipsychotics in patients of all ages.
Blood cell monitoring is required for the use of clozapine. The first 6 months a complete blood count must be obtained weekly, then every other week for the next 6 months and then monthly as long as one takes the medication.
If you miss a dose of clozapine do not take the missed dose with the next dose. If you miss more than 2 days of clozapine, call the office for an appointment for guidance in restarting it. It is particularly important to take clozapine regularly as prescribed.
