Melperone in the treatment of iatrogenic psychosis in Parkinson's disease.

The pharmacological management of Parkinson's disease (PD) can be complicated by psychiatric disorders induced by antiparkinsonian drugs. The reduction or withdrawal of levodopa (l-dopa) and other drugs commonly used in the treatment of PD may attenuate the psychosis but exacerbate motor impairment and disability. Melperone is an atypical antipsychotic drug showing in vivo a greater relative affinity for the 5-HT2 than the D2 receptors. A two-year study to assess the clinical efficacy and the safety of melperone in the management of iatrogenic psychosis in 30 parkinsonian patients was carried out. Neurological evaluation was performed with patients in the "off" and in the "on" state using the motor examination of the Unified Parkinson's Disease Rating Scale (UPDRS). Time spent in "on" state was evaluated using the self-evaluation diary of daily life. To assess psychiatric disturbances the modified version of the Brief Psychiatric Rating Scale (BPRS) was used. The mean BPRS score was significantly reduced when comparing baseline with individual examinations; no statistically significant differences were found between subsequent examinations. UPDRS motor score and time spent in "on" state during daily life showed no statistically significant differences when comparing baseline with subsequent examinations. Two patients dropped out because of excessive sedation problems but in the remaining 28 patients melperone proved to be optimally tolerated.