Hi Thanks for your query. Prozac (Fluoxetine) is one of the most commonly used medication to treat psychiatric illnesses like depression, obsessive compulsive disorder, etc. The common side effects are sleep disturbances, sexual dysfunction, increased appetite and weight gain. Olanzapine is an atypical antipsychotic drug, its use is associated with weight gain, increase in blood glucose and cholesterol levels, increase risk of getting decrease white blood cells count. These medications are less likely to increase the production of Prolactin hormone from the anterior pituitary gland as compared to the older antipsychotic medications. Hope this answers your query. A feed back is appreciated.