Tolcapone improves sleep in patients with advanced Parkinson's disease (PD)

Efficacy of the long-acting catechol-O-methyltransferase (COMT)-inhibitor, tolcapone on sleep quality was studied in 61 patients with advanced PD in a prospective open-label multicenter non-interventional trial. Main outcome measures were the PD sleep scale (PDSS). Further outcome measures were global clinical impression of change (GCI-C), daily off-time, activities of daily living (UPDRS part II), quality of life (EuroQoL-5D), Epworth sleepiness scale (ESS) and adverse events reports. All efficiency and safety parameters were assessed 4 weeks after the switch to tolcapone and compared to baseline. The mean±S.D. daily dose of tolcapone was 294.2±36.9 mg/day at the final assessment. The mean PDSS scores significantly improved from 21.6±8.1 at baseline to 16.3±7.7 at final assessment (p<0.0001). Consistently, daytime sleepiness was significantly reduced as reflected by lower scores on the ESS (p=0.0057). Further efficacy parameters including GCI-C, daily off-time, activities of daily living, and quality of life were also significantly improved. Tolcapone was in general well tolerated and safe. This observational study provides first evidence that tolcapone improves sleep quality and reduces daytime sleepiness in patients suffering from advanced PD.