Safety studies and adverse reactions
Potential medication effects on middle-of-the-night and next-morning postural stability (body sway measured with an ataxiameter) and cognitive performance, as well as middle-of-the-night auditory awakening threshold, were assessed in a randomized, 4-way crossover study of 56 healthy older adults (women age ≥55 [77.8%], men age ≥65) given a single bedtime dose of placebo, lemborexant, 5 mg, lemborexant, 10 mg, and zolpidem extended-release, 6.25 mg, on separate nights.11 The results were compared with data from a baseline night with the same measures performed prior to the randomization. The middle-of-the-night assessments were done approximately 4 hours after the dose and the next-morning measures were done after 8 hours in bed. The auditory threshold analysis showed no significant differences among the 4 study nights. Compared with placebo, the middle-of-the-night postural stability was significantly worse for both lemborexant doses and zolpidem; however, the zolpidem effect was significantly worse than with either lemborexant dose. The next-morning postural stability measures showed no significant difference from placebo for the lemborexant doses, but zolpidem continued to show a significantly worsened result. The cognitive performance assessment battery provided 4 domain factor scores (power of attention, continuity of attention, quality of memory, and speed of memory retrieval). The middle-of-the-night battery showed no significant difference between lemborexant, 5 mg, and placebo in any domain, while both lemborexant, 10 mg, and zolpidem showed worse performance on some of the attention and/or memory tests. The next-morning cognitive assessment revealed no significant differences from placebo for the treatments.
Respiratory safety was examined in a placebo-controlled, 2-period crossover study of 38 patients diagnosed with mild obstructive sleep apnea who received lemborexant, 10 mg, or placebo nightly during each 8-day period.12 Neither the apnea-hypopnea index nor the mean oxygen saturation during the lemborexant nights were significantly different from the placebo nights.
The most common adverse reaction during the month-long Sunrise 1 study and the first 30 days of the Sunrise 2 study was somnolence or fatigue, which occurred in 1% receiving placebo, 7% receiving lemborexant, 5 mg, and 10% receiving lemborexant, 10 mg. Headache was reported by 3.5% receiving placebo, 5.9% receiving lemborexant, 5 mg, and 4.5% receiving lemborexant, 10 mg. Nightmare or abnormal dreams occurred with 0.9% receiving placebo, 0.9% receiving lemborexant, 5 mg, and 2.2% receiving lemborexant, 10 mg.1
Unique clinical issues
Because investigations of individuals who abused sedatives for recreational purposes showed lemborexant had a likeability rating similar to zolpidem and significantly greater than placebo, the US Drug Enforcement Agency has categorized lemborexant as a Schedule IV controlled substance. Research has not shown evidence of physical dependence or withdrawal signs or symptoms upon discontinuation of lemborexant.1
Contraindications
Narcolepsy is the only contraindication to the use of lemborexant.1 Narcolepsy is associated with a decrease in the orexin-producing neurons in the hypothalamus, presumably causing the excessive sleepiness, sleep paralysis, hypnagogic hallucinations, and cataplexy characteristic of the disorder. Hypothetically, an orexin antagonist medication could exacerbate these symptoms.
Continue to: Dosing