Investigation of the Pharmaceutical Care in One Elderly Parkinson’s Disease Patient with Psychotic Symptoms

A 66-year-old male patient with a 10-year course of Parkinson’s disease (PD) was admitted for hallucination lasting a half a month. After treatment with levodopa/carbidopa, selegiline, and piribedil, the patient’s motor symptoms were improved while no significant effects were observed on psychotic symptoms. A clinical pharmacist analyzed the pharmacologic and pharmacokinetic characteristics of selegiline and piribedil, summarized the scheme of PD with psychotic symptoms in the literature, and discovered that selegiline might potentiate psychotic side effects of piribedil, while the use of levodopa/carbidopa cannot be ruled out either. Finally, the clinical pharmacist proposed to reduce the dosage of levodopa/carbidopa, increase the dosage of selegiline and quetiapine, and discontinue piribedil. The clinician accepted this suggestion. After the adjustment of medication, the patient’s motor symptoms were absolutely improved and the psychotic symptoms were notably improved. This case study suggests that long-term treatment with levodopa/carbidopa and piribedil, along with the progression of the disease itself, could contribute to the emergence of psychotic symptoms in PD. Additionally, selegiline could potentiate psychotic side effects of piribedil. Neurology clinical pharmacists should work alongside neurology clinicians at the bedside to optimize pharmacotherapy, improve patient safety, and contribute to scholarly efforts.