EFFECTS OF SUVOREXANT ON SLEEP IN FIBROMYALGIA

The chronic pain disorder, fibromyalgia, is associated with sleep disturbance, typically sleep maintenance. Pharmacological treatment studies have either focused on the pain or the sleep disturbance with equivocal results in that few studies have improved both sleep and pain. No studies have evaluated the effect of sleep medication on pain sensitivity. Suvorexant, an orexin antagonist, approved for treatment of insomnia may provide benefit for both the sleep and pain of fibromyalgia.. Here we report on suvorexant’s sleep effects in patients with fibromyalgia and comorbid insomnia disorder gathered as part of a feasibility study. Women, 21- 65 yrs old, with fibromyalgia and co-morbid insomnia (n=10) were treated for 9 nights with suvorexant, 20 mg, and placebo with the order of the treatments counterbalanced. They were in good psychiatric and stable physical health and met American College of Rheumatology criteria for fibromyalgia and DSM-V criteria for insomnia. On a screening 8-hr PSG other primary sleep disorders were ruled out. On nights 8 and 9 of each treatment 8-hr PSGs were collected. All PSGs were scored following ASSM criteria and PSG measures were compared using repeated measures ANOVAs with night and drug condition as factors. Suvorexant vs placebo increased total sleep time (7.2 vs 6.7 hrs, p< .05) and reduced wake after sleep onset (37 vs 67 min, p