I have been on prescription Olanzapine for over a year due to a schizophrenic-type illness with psychotic episodes. Olanzapine has been a successful treatment for me - it counteracts psychotic symptoms in about a week. Recently I stopped medicating and smoked some marijuana which prompted a return to mild psychosis and I restarted the Olanzapine - within a week I was back to my normal self, but it does take time to build up in the body which kind of undermines any recreational value I would have thought.
I have used methamphetamine regularly by iv for about 4 months without noticing any contraindications from mixing with medication nor from psychotic symptoms caused by using the meth itself.
The negative effects of Olanzapine I have noticed include putting on weight, reduction in libido, and after a long time on a high dose excessive drowsiness that makes it difficult to hold down a job. Incidentally I have been working normally during this whole time, which would not have been possible without the stabilizing effects of Olanzapine.
I am intending to conduct some experiments with certain psychoactives to see if they re-trigger psychotic episodes in me - if anything goes wrong I have the olanzapine and I know it usually straightens me out in about a week on 20mg a day.