Improvement of sleep and pain with lemborexant administration in patients with chronic pain: a retrospective observational study.

Objective: Patients with chronic pain often have sleep disturbances, and many patients receive sleep medications in addition to analgesics. Although there have been scattered reports of negative pain-sleep interactions, only a few reports have investigated the efficacy of sleep medication interventions in patients with chronic pain for improving sleep disturbances and reducing pain. We retrospectively examined whether lemborexant, an orexin receptor antagonist, is effective in improving sleep disturbances and reducing pain in patients with chronic pain. This study was approved by the Ethics Committee of our hospital.

Methods: The subjects were 26 patients with chronic pain undergoing treatment at our pain clinic between July 2021 and March 2022, who had been diagnosed with insomnia, with an Athens Insomnia Scale (AIS) score of ≥6 and had been started on lemborexant. The AIS score and pain score (Numeric Rating Scale [NRS]) before and after 2 and 4 weeks of starting lemborexant were investigated.

Results: Patients who were already taking other sleep medications, such as benzodiazepines were switched to 5 mg of lemborexant after all the other sleep medications were discontinued. Those who had not yet used sleeping pills were started on 5 mg of lemborexant. During the study course, the dose of lemborexant was adjusted at the discretion of the attending physician, based on improvement of insomnia symptoms and secondary symptoms, such as daytime sleepiness and lightheadedness. The study finally included 21 patients, excluding 5 who could not continue taking lemborexant due to side effects, such as lightheadedness. The AIS scores significantly improved, decreasing from baseline (mean ± standard deviation: 12.5 ± 4.9) to 2 weeks (7.8 ± 3.1) and 4 weeks (5.3 ± 2.9) after the start of lemborexant. No significant difference was observed in the degree of improvement in sleep disturbance between patients with or without previous sleep medications, and there was also no statistically significant improvement in the NRS score before (6.1 ± 2.7) and after 2 weeks (5.5 ± 2.3) and 4 weeks (5.9 ± 2.2) from treatment initiation.