Discontinuing long-term pharmacotherapy for insomnia can result in rebound insomnia or withdrawal symptoms and suboptimal treatment. Post hoc analyses evaluated rebound insomnia and withdrawal symptoms among the subset of subjects from a phase III, 12-month, global, multicenter, randomized, double-blind, parallel-group study who completed 12 or 6 months of active treatment and follow-up period. Study E2006-G000-303 (Study 303) included adults (N = 655) with subjective sleep-onset latency ≥30 min and/or subjective wake-after-sleep onset ≥60 min at least three times weekly during the 4 weeks before enrollment. Subjects were randomized 1:1:1 to lemborexant 5 mg (LEM5) or 10 mg (LEM10) or placebo for 6 months. Thereafter, for an additional 6 months, LEM5- and LEM10-treated subjects continued lemborexant and the placebo group was rerandomized 1:1 to LEM5 or LEM10. Month 12 was followed by abrupt discontinuation and a 2-week end-of-study follow-up. Using daily electronic sleep diaries, patients reported (subjective) sleep end points (sleep-onset latency, wake-after-sleep onset, sleep efficiency, and total sleep time). Withdrawal symptoms were assessed using the Tyrer Benzodiazepine Withdrawal Symptoms Questionnaire (T-BWSQ). Sleep outcome improvements with lemborexant at month 12 were generally maintained throughout the 2-week off-treatment period wherein <20% of subjects experienced significant worsening of insomnia symptoms versus screening. There was no evidence of withdrawal symptoms by T-BWSQ following lemborexant discontinuation. This analysis demonstrates rebound insomnia is unlikely to occur with lemborexant, and its effectiveness is maintained after abrupt discontinuation without placebo replacement following 6-12 months of treatment.
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