帕金森氏症病人長期使用藥物治療時，有不少的病人會出現精神症狀，包括幻覺、妄想、譫妄、焦慮、認知功能缺損及其它精神症狀等，常常會影響治療的療程。引起該副作用的原因雖然不完全清楚，但被認為可能與腦中掌管運動功能之多巴胺徑路傳導物質-多巴胺及乙醯膽鹼不平衡有關。危險因子包括老年人、多種抗帕金森藥物併用、精神狀態混亂、長期失眠、合併有憂鬱症，失智症或躁症及安置於護理之家的帕金森氏症病人。當病人出現該藥物副作用時，應先降低抗帕金森藥物的使用劑量或停用，若經上述方法處理後，精神症狀仍無法有效獲得緩解時，可加入非典型抗精神病劑治療。

本文針對一位患有帕金森氏症的老年人，因使用抗帕金森藥物引起精神病而住院，但住院時仍使用多種抗帕金森藥物而未能給與即時及有效的治療處置，經臨床藥師介入建議其調降藥物劑量及調整使用順序後，病人的精神症狀獲得有效改善之案例報告。
 

Psychiatric symptoms develop in 20-30% patients with Parkinson’s disease who receive drug treatment.  The symptoms include visual hallucination (20-40%), paranoid delusion (8%), delirium, anxiety, cognitive impairment, and others, and are accounted for the adverse effects caused by the anti-parkinsonian agents. The risk factors for drug-induced psychosis in patients with Parkinson’s disease include advanced age, living at the nursing home, concomitant use of multiple antiparkinsonian drugs, comorbid with other psychiatric illness like depression, dementia or manic episode. Occurrence of psychiatric symptoms not only affects the treatment and care of the patient with Parkinson’s disease, but also increases the risk of mortality.  Dosage reduction or discontinuation of the anti-parkinsonian drug is the initial step in managing psychiatric symptoms; while antipsychotic medication, preferably the atypicals, is needed if the symptoms persist.
We report a case of Parkinson’s disease who developed psychotic symptoms while taking multiple antiparkinsonian drugs.  After intervention by clinical pharmacist, appropriate steps in reduction and correction of antiparkisonian drugs were given. The psychotic symptoms were alleviated after correcting the remedy.