Patients with chronic pain who took opioids reported significantly more difficulty falling asleep, compared with those who didn’t use opioids, a study of 144 adults has found.
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“Identification of factors that influence insomnia symptoms among adults with chronic pain may inform prevention and treatment efforts for both disorders,” wrote Mary Beth Miller, PhD, of the University of Missouri School of Medicine, Columbia, and her colleagues.
To identify the potential impact of opioid use on sleep among chronic pain patients, the researchers recruited adults reporting symptoms of both insomnia and fibromyalgia. The average age of the participants was 52 years, and 95% were women. The study findings were published in Sleep Medicine.
The participants completed sleep diaries for 14 days, during which they recorded data including when they went to bed, how long it took them to fall asleep (SOL), how often they woke up during the night and how long they stayed awake (WASO), what time they woke up, and what time they got out of bed. Patients also reported “yes” or “no” on opioid use and their dosage each day and rated their pain on a scale of 0-100 each night before retiring.
The study participants wore wrist actigraphy devices for baseline assessment and underwent 1 night of ambulatory polysomnography.
The researchers used a multiple regression model to examine how pain intensity affected the association between opioid use and insomnia.
Overall, “opioid use was not associated with improvements in insomnia symptoms across any level of pain intensity, and was associated with worse insomnia symptoms among those reporting less intense pain,” the researchers said.
Opioid use was associated with significantly longer time to sleep onset in participants with low levels of pain (P = .02) but not among those with moderate to high levels; average sleep onset latency appeared unaffected by pain level among participants who did not use opioids.
The study findings were limited by several factors including the small number of male participants, the use of paper forms for the sleep diaries, which prevented confirmation of timely reporting, and the cross-sectional nature of the analysis, the researchers noted. However, from a clinical perspective, the “findings suggest that it may be important to advise patients reporting symptoms of insomnia about the risks of extending time in bed when providing them with opioid pain medication and that the use of behavioral or cognitive-behavioral treatment for insomnia may be recommended,” they said. The researchers also recommended that future studies address the longitudinal associations between opioid use and insomnia.
The researchers had no financial conflicts to disclose.
SOURCE: Miller M et al., Sleep Med. 2018; doi: 10.1016/j.sleep.2018.08.015.