Olanzapine is sold under the brand name "Zyprexa".
Olanzapine is an atypical antipsychotic closely related to clozapine and quetiapine. It is FDA approved for the acute and maintenance treatment of Bipolar Disorder and Schizophrenia and for the acute treatment of agitation in Bipolar Disorder and Schizophrenia.
Each of the atypical antipsychotics has its own profile or personality. Olanzapine seems to have the most liability to weight gain of the commonly used atypical antipsychotics. It also is perceived as particularly effective in Bipolar Disorder, possible more so than all of the other atypical antipsychotics with the exception of clozapine.
Olanzapine 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).
Olanzapine 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 olanzapine is about one day and consequently if stopped abruptly (not recommended) it is out of the body in about 5 days.
Possible adverse effects can include diabetes, weight gain, abnormal triglycerides and cholesterol, insulin resistance, sedation, dizziness, dry mouth, constipation, and others. These is data that suggest this category of medication can rarely cause strokes in the elderly.
Olanzapine, 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 olanzapine 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.
Olanzapine has no effects on liver enzyme systems and consequently does not significantly effect the elimination of other medications.
If you miss a dose of olanzapine do not add it to your next dose. Take olanzapine regularly as prescribed.
Links:
FDA patient information for the combination of olanzapine and fluoxetine
