Changes in Clinical Outcomes and Peripheral Cytokines during Duloxetine Add‐on Therapy in Parkinson's Disease

BACKGROUND: Neuroinflammation is implicated in Parkinson's disease (PD), and antidepressants may have anti-inflammatory and motor benefits. The effects of duloxetine on inflammatory biomarkers and clinical outcomes in PD remain unclear. OBJECTIVES: To assess changes in motor symptoms, quality of life, and serum cytokines during add-on duloxetine treatment in PD. METHODS: Seventeen patients with PD without other chronic inflammatory diseases received add-on duloxetine for 8 weeks in an open-label, uncontrolled trial. Clinical outcomes included Unified Parkinson's Disease Rating Scale (UPDRS), modified Hoehn and Yahr (HY), and Parkinson's Disease Questionnaire-39 (PDQ-39) scores. Serum TNF-α, IL-1β, IL-6, and IL-10 levels were measured at baseline and follow-up. RESULTS: UPDRS, activities of daily living, and PDQ-39 scores decreased during treatment. Ten patients achieved ≥5-point UPDRS reductions. TNF-α, IL-1β, and IL-6 decreased, whereas IL-10 increased after treatment. CONCLUSIONS: Add-on duloxetine was associated with changes in clinical outcomes and inflammatory markers in patients with PD.