Wake up to sleep: The effects of lacosamide on daytime sleepiness in adults with epilepsy

- Daytime sleepiness, fatigue, and sleep complaints are common in adults with epilepsy.
- Sleep propensity and mean sleep latency were similar in LCM and placebo groups.
- Change in seizures and AED standardized dose did not impact outcomes.
- Given prevalence, inclusion of sleepiness measures in AED trials is recommended.

ObjectiveThe objective of the study was to investigate the effects of lacosamide (LCM) on daytime sleepiness ascertained by the Epworth Sleepiness Scale (ESS) in adults with focal epilepsy in a randomized, controlled design.MethodsSubjects taking ≤ 2 AEDs for ≥ 4 weeks underwent polysomnography with EEG followed by the maintenance of wakefulness test (MWT) and completed the ESS and other patient-reported outcomes (PROs) at baseline, LCM 200 mg/day, and LCM 400 mg/day (Visit 4; V4). Primary endpoint was ESS change (V4 to baseline) between LCM and placebo. Noninferiority test on ESS used a one-sided t-test based on a hypothesized difference of 4-point change between groups. Superiority test used a two-sided t-test to investigate the difference in change in PROs and MWT mean sleep latency (MSL) between groups. Fifty-five subjects provided 80% power to show noninferiority of LCM assuming 10% dropout.ResultsFifty-two subjects (mean age: 43.5 ± 13.2 years, 69% female, median monthly seizure frequency: 1 [0, 4.0]) participated. Baseline group characteristics including age, sex, ethnicity, standardized AED dose, seizure frequency, and ESS were similar. Abnormal baseline ESS scores were found in 35% of subjects. Noninferiority test found a ≤ 4-point increase in ESS (mean [95% CI]) in LCM subjects vs. placebo (− 1.2 [− 2.9, 0.53] vs. − 1.1 [− 5.2, 3.0], p = 0.027) at V4. No significant difference in change in PROs, MSL, seizure frequency, or AED standardized dose was observed between groups.SignificanceOur interventional trial found that LCM is not a major contributor to daytime sleepiness based on subjective and objective measures. Inclusion of sleepiness measures in AED trials is warranted given the high prevalence of sleep-wake complaints in people with epilepsy.