Prolonged-release melatonin in Parkinson's disease patients with a poor sleep quality: A randomized trial

The present study was a randomized, double-blind, placebo-controlled, multi-center trial to evaluate the efficacy and safety of prolonged-release melatonin (PRM) in Parkinson's disease (PD) patients with poor sleep quality.

PD patients with a global Pittsburgh Sleep Quality Index (PSQI) score > 5 were included. Patients were assessed using the PSQI, a rapid eye movement sleep behavior disorder screening questionnaire, the Epworth Sleepiness Scale, Non-Motor Symptoms Scale (NMSS), Parkinson's Disease Quality of Life-39 (PDQ-39), and Unified Parkinson's Disease Rating Scale (UPDRS)-III at the beginning of the study and after 4 weeks of treatment with 2 mg of PRM. Partial correlation analysis was performed to investigate the relationship between PSQI score and the other scales.

Thirty-four PD patients with poor sleep quality were enrolled and divided into 2 groups based on medication; PRM (n = 16) and placebo (n = 18). Regarding efficacy, PSQI was significantly improved in the PRM group compared to the control group. Improvement in the NMSS and PDQ-39 summary index were observed in the PRM but not in the placebo group; UPDRS-III score was not significantly changed in either group. PSQI improvement correlated with improvement in NMSS score and PDQ-39 summary index. Regarding safety, all enrolled subjects did not complain of side effects due to PRM.

PRM is an effective and safe treatment option for subjective sleep quality in PD patients and beneficial effects on sleep quality are associated with improved non-motor symptoms and quality of life in PD patients.