Olanzapine

Olanzapine (brand name Zyprexa) is an atypical antipsychotic drug belonging to the thienobenzodiazepine family, made by Eli Lilly & Co. It is a yellow crystaline solid, with chemical formula C₁₇H₂₀N₄S. It is not yet known, but it most likely works as a dopamine antagonist as well as a serotonin 5-HT₂ antagonist.

Olanzapine was the first of the atypical antipsychotics to be approved for long-term treatment of schizophrenia. It has been prescribed to over 6 million patients in 84 countries since it became available in 1996. Olanzapine is also approved for the short-term treatment of bipolar mania. The most common side effects are somnolence and weight gain.

Sources:
http://www.rxlist.com/cgi/generic/olanzapine.htm
http://www.zyprexa.com/hcp/html/zyhcp_facts.shtml
http://www.healthyplace.com/medications/olanzapine.htm
http://www.priory.com/focus3.htm

It has been said that if the public knew exactly how much weight gain olanzapine caused, nobody would take it.

Ha! Eli Lily is not going to like me. According to one clinical researcher who gave a talk on Ziprasidone (Pfizer's new baby), the typical schizophrenic on a typical dose of olanzapine could expect to gain a grand total of 13kg over 1 year.

In a weight conscious population, how many people would continue taking a long term drug, knowing it would result in such significant weight gain?

Doctors commonly warn patients and their family of weight gain while on olanzapine but few actually mention the degree ...