Olanzapine Levodopa

A number of unapproved uses of antipsy- chotic drugs also exist. CPZ and haloperidol were used early on to treat phencyclidine (PCP)-induced psychosis. Psychoses associ- ated with depression, bipolar disorder, and Alzheimer s disease are commonly treated with haloperidol, risperidone, or olanzapine. Psychotic symptoms in Parkinson s disease patients caused by levodopa and/or dopaminergic agonists have been alleviated with quetiapine, because EPS-prone typical neuroleptics contraindicated in Parkinson s disease. 

Phenothiazines, butyrophenones, diphenylbutylpiperidines and thioxanthenes can oppose the effects of levodopa because of their dopamine antagonist properties, causing deterioration of motor function in Parkinson s disease. The antipsychotic effects and ex-trapyramidal adverse effects of these drugs can be opposed by levodopa. Of the atypical antipsychotics, risperidone and olanzapine cause deterioration in motor function in Parkinson s disease. Ziprasidone may act similarly, and there have been reports with quetiapine. Clozapine does not have this effect. 

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