Risperidone Levodopa

Intolerable exacerbation of parkinsonism with risperidone has been reported (SEDA-20, 52), and even a 12-year-old boy reportedly developed parkinsonian tremor while taking risperidone (76). However, in contrast, eight patients (five women, three men) with advanced Parkinson s disease, motor fluctuations, and levodopa-induced dyskinesia took part in an open study with a low dosage of risperidone (mean 0.187 mg/day) after an average of 11 months all the patients had moderate to pronounced reductions in levodopa-induced dyskinesias (77). 

Meco G, Fabrizio E, Alessandri A, Vanacore N, Bonifati V. Risperidone in levodopa induced dyskinesiae. J Neurol Neurosurg Psychiatry 1998 64(1) 135. 

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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