A non-comparative assessment of tolerability and efficacy of duloxetine in the treatment of depressed patients with Parkinson's disease

Objective: Depression is a comorbidity affecting quality of life (QoL) in patients with Parkinson's disease (PD) and requires appropriate treatment. This study evaluated the tolerability, safety, and efficacy of duloxetine 60 mg once daily for 12 weeks in PD patients with major depressive disorder (MDD). Research and design methods: Non-comparative, open-label, multi-center study. Main outcome measures: Tolerability was evaluated by discontinuation rate (acceptable if <= 19%) due to treatment-emergent adverse events (TEAEs) and motor symptoms (UPDRS). Safety measures were TEAEs, the UKU side effect rating scale, vital signs, weight, laboratory tests, and ECG. Efficacy measures included HAMD-17, BDI, CGI-S, PGI-I, and pain VAS. QoL was measured by PDQ-39. Results: Of the 151 patients enrolled, 8.6%(95% upper CI: 13.3%) discontinued the study due to TEAEs. Worsening in PD-related tremor and rigidity was not observed, activities of daily living significantly improved and UKU subscales progressively decreased. Clinically significant abnormalities in laboratory findings were limited to four cases of hypercholesterolemia and one increase of total bilirubin, CPK, and fasting glucose. Blood pressure, weight, and ECG did not change from baseline. HAMD-17 and PDQ-39 total score and individual domains, BDI, CGI-S, and PGI-I total scores significantly improved. Conclusions: Duloxetine seems well tolerated and likely effective in the treatment of depression associated with PD, with no detrimental effects in PD signs and symptoms.