Clozapine Case Summary

Initially Clozapine was suggested as the ideal treatment of Parkinson’s disease psychosis and the first report of its use was in a single patient in 1985. The patient who also suffered from schizophrenia and ultimately developed idiopathic Parkinson’s disease, became intolerant of any antipsychotic because of extremely severe Parkinsonism. The psychosis also worsened with the use of anti-Parkinson medication without the use of an antipsychotic. Ultimately the patient was put on Clozapine which improved both the motor function and psychiatric condition. Two multicenter double blind placebo controlled trials were performed in the United States and in France. Both trials shared a similar protocol and the results produced were almost identical.

It is common, for example, in people with parkinson’s disease that anticholinergic agents are used to control bladder over activity, and benzodiazepines for anxiety. Only when Parkinson’s disease medications have been reduced as much as can be tolerated, then quetiapine is to be considered. This recommendation is not evidence based and is instead based on the experience of clinicians. Clozapine, despite level 1 evidence to support its use, was also to be “considered” due to the logistical problem of blood monitoring. The committee felt that quetiapine, although not having randomized controlled trial data to support its use, did have the data to support its safety, whereas all other atypical antipsychotics, excepting clozapine, did not. Aripiprazole is to be consider the third line agent, although data indicate that it is likely to worsen some patients. Cholinesterase inhibitors have also been used but not reported nearly as extensively as the AA. The data suggest mild benefit only, and the benefit may take weeks to develop. Rare case reports of electroconvulsive therapy (ECT) as an effective treatment for psychosis have been published. ECT has been known for several decades to improve motor function as a bonus when Parkinson’s diseases patients with severe depression have been treated. Unfortunately, the motor benefit is sustained only for days to weeks not making it a viable long term alternative. (Hasnain,