Also Known As: Olanzapine, Zyprexa, Zalasta, Zolafren, Olzapin, Oferta, Zypadhera
Olanzapine (trade names Zyprexa, Zalasta, Zolafren, Olzapin, Oferta, Zypadhera or in combination with fluoxetine Symbyax) is an atypical antipsychotic, approved by the FDA for the treatment of schizophrenia and bipolar disorder. Olanzapine is structurally similar to clozapine, but is classified as a thienobenzodiazepine. The olanzapine formulations are manufactured and marketed by the pharmaceutical company Eli Lilly and Company; the drug went generic in 2011. Sales of Zyprexa in 2008 were $2.2B in the US alone, and $4.7B in total.
- oral formulation: acute and maintenance treatment of schizophrenia in adults, acute treatment of manic or mixed episodes associated with bipolar I disorder (monotherapy and in combination with lithium or valproate)
- intramuscular formulation like Zyprexa IntraMuscular: acute agitation associated with schizophrenia and bipolar I mania in adults
- oral formulation combined with fluoxetine: treatment of acute depressive episodes associated with bipolar I disorder in adults, or treatment of acute, resistant depression in adults 
Known FDA approvals are as follows:
- approved for the treatment of the manifestations of psychotic disorders on September 6, 1996
- approved in combination with fluoxetine for the treatment of depressive episodes associated with Bipolar disorder on December 24, 2003
- approved for the long-term treatment of bipolar I disorder on January 14, 2004
- approved in combination with fluoxetine for treatment of resistant depression on March 19, 2009.
Case-reports, open-label, and small pilot studies suggest efficacy of olanzapine for the treatment of some anxiety spectrum disorders (e.g. generalized anxiety disorder, panic disorder, delusional parasitosis, post-traumatic stress disorder); however, olanzapine has not been rigorously evaluated in randomized, placebo-controlled trials for this use and is not FDA approved for these indications. Other common off-label uses of olanzapine include the treatment of eating disorders (e.g. anorexia nervosa) and as an adjunctive treatment for major depressive disorder without psychotic features. It has also been used for Tourette syndrome and stuttering.
Prevention of psychosis
Olanzapine has been considered as part of an early psychosis approach for schizophrenia. The Prevention through Risk Identification, Management, and Education (PRIME) study, funded by the National Institute of Mental Health and Eli Lilly, tested the hypothesis that olanzapine might prevent the onset of psychosis in people at very high risk for schizophrenia. The study examined 60 patients with prodromal schizophrenia, who were at an estimated risk of 36–54% of developing schizophrenia within a year, and treated half with olanzapine and half with placebo. In this study, patients receiving olanzapine did not have a significantly lower risk of progressing to psychosis. Olanzapine was effective for treating the prodromal symptoms, but was associated with significant weight gain.