Safety profile and clinical course of patients with insomnia administered suvorexant by initial treatment status in a post-marketing survey.

: Suvorexant is a dual orexin receptor antagonist used for treating insomnia. The authors elucidated the safety profiles and clinical course of insomnia therapy with suvorexant under different initial treatment status seen in daily routine practice. : Subgroup analysis of a post-marketing survey (PMS; 2015-2017) divided patients based on their initial treatment status with suvorexant into 'hypnotic-naïve (Group N)', 'switching from a prior sleep medication (Group S),' 'add-on therapy (Group A),' and 'others (Group O).' : Among 3248 patients analyzed in the PMS, the number of patients in Groups N, S, A, and O was 1946 (59.9%), 703 (21.6%), 536 (16.5%), and 63 (1.9%), respectively. The incidence of insomnia-related adverse drug reactions (ADRs) in Group S (5.3%) tended to be higher than that in Groups N (0.46%) and A (1.5%). Discontinuation rate due to an inadequate effect at 6 months in Group S (14.9%) tended to be higher than that in Groups N (9.6%) and A (10.4%). : The results suggest that initiating suvorexant treatment after switching from other insomnia medication must require careful monitoring of insomnia-related ADRs, which might be due to abrupt discontinuation of the prior insomnia medication use.