Indication for the acute and maintenance treatment of schizophrenia and related psychotic disorders, as well as acute treatment of manic or mixed episodes of bipolar 1 disorder. intramuscular olanzapine is indicated for the rapid control of agitated patients.mechanism of action olanzapine s antipsychotic activity is likely due to a combination of antagonism at d2 receptors in the mesolimbic pathway and 5ht2a receptors in the frontal cortex. antagonism at d2 receptors relieves positive symptoms while antagonism at 5ht2a receptors relieves negative symptoms of schizophrenia.