Orexin Inhibitors for Sleep Maintenance Insomnia

Efficacy and Safety

• The American Academy of Sleep Medicine suggests that suvorexant reduces wake after sleep onset by 21-28 minutes and increases total sleep time by approximately 50 minutes on polysomnography at 20 mg, but at 10 mg these benefits are smaller, with a 22 minutes increase in total sleep time 1, 2, 3
• Patient-reported sleep improvements frequently did not meet the predefined clinical significance threshold, with subjective total sleep time improvements of only 5.5-10.6 minutes at approved doses 2, 3, 4
• The American Academy of Sleep Medicine rated the overall quality of evidence as LOW to VERY LOW due to imprecision, potential publication bias, and significant heterogeneity 1, 2, 3
• Higher doses (30-40 mg) showed better efficacy but were rejected by the FDA due to dose-dependent increases in daytime somnolence (up to 8.4% vs 3.1% placebo at 15/20 mg doses) 1, 2, 3
• Somnolence increases in a dose-dependent fashion, with frequency of somnolence noted to increase significantly at dosages exceeding FDA-recommended levels 1, 2, 3
• The FDA labeling warns of cognitive and behavioral changes including amnesia, anxiety, hallucinations, and other neuropsychiatric symptoms 5, 6
• The American Academy of Sleep Medicine suggests suvorexant as a treatment option rather than a preferred first-line agent for sleep maintenance insomnia in adults, reflecting the modest strength of evidence 5
• Lower doses (5-10 mg) are recommended as second-line treatment when cognitive behavioral therapy for insomnia is unsuccessful, not as initial pharmacotherapy 5
• The task force determined that a majority of patients would likely use suvorexant compared to no treatment, but this assessment was based on clinical judgment rather than robust patient preference data 1, 2, 3