Association between dopaminergic medications and nocturnal sleep in early-stage Parkinson's disease

Poor nocturnal sleep is common in Parkinson's disease (PD) and negatively impacts quality of life. There is little data on how dopaminergic drugs influence nocturnal sleep in PD, particularly in relation to medication timing. We examined the association between dopaminergic medications and subjective and objective nocturnal sleep in PD.

Individuals with PD were recruited from the outpatient clinic. Demographics and disease information were collected. Patients underwent one-night polysomnography and responded to SCOPA-SLEEP, a self-administered questionnaire which includes a section on nighttime sleep and an overall measure of sleep quality; higher scores indicate worse sleep. Medication intake, including medication timing in relation to bedtime, was obtained and converted to levodopa equivalents.

41 Males and 21 females, median age 63.9 years, participated. Median disease duration was 5 years. After adjusting for age, sex, disease severity, and disease duration, greater total levodopa equivalent intake within 4 h of sleep was associated with higher total SCOPA-nighttime score (p = 0.009) and greater wake time after sleep onset (p = 0.049). Greater dopaminergic medication intake prior to sleep was also associated with less rapid eye movement (REM) sleep as a percent of total sleep time (p = 0.004).

Higher amounts of dopaminergic medications taken prior to sleep were associated with poor sleep quality and less REM sleep. Although poor nocturnal sleep in PD is likely multi-factorial in etiology, our findings suggest that timing and dose of medications prior to sleep need to be considered in its management.