Effects of modafinil on nocturnal sleep patterns in patients with narcolepsy: A cohort study

Background: Patients with narcolepsy often experience disturbed nighttime sleep. Modafinil is commonly prescribed for hypersomnolence, but its impacts on nocturnal sleep remain unclear. This study uses actigraphy to examine the effect of modafinil on both hypersomnolence and nocturnal sleep patterns in patients with narcolepsy. Methods: Prior to treatment, 87 patients with narcolepsy wore an actigraphy for 7–14 days to assess their nighttime sleep. After evaluation, they received a daily dose of 200–400 mg of modafinil in the morning and wore an actigraphy again six months after initiating treatment. Questionnaires, including the Epworth-Sleepiness-Scale (ESS), the Visual-Analogue-for-Hypersomnolence (VAS), and the Short-Form-36-Health-Survey (SF-36), were used to evaluate hypersomnolence and quality of life both before and after treatment. Paired t-tests and independent samples t-tests were used for pre- and post-treatment comparisons and subgroup analysis. We used the Pearson's correlation test to measure the correlations between the sleep parameters of the actigraphy and data of the questionnaires. Results: Improvements in hypersomnolence were noted following modafinil treatment, and we observed no significant deterioration in nocturnal sleep parameters by the actigraphy. The total number of awakenings by actigraphy significantly decreased (p = 0.005), especially in females (p = 0.008), while sleep onset latency significantly increased in children/adolescents (p = 0.014). Correlations were found between the sleep parameters of the actigraphy and ESS, VAS, and SF-36 scores. Conclusion: Modafinil treatment may not worsen nighttime sleep in patients with narcolepsy. However, it should be administered with care in children and adolescents.