June 2024
Onyeakazi UM, Columb MO, Rosalind A, Kanakarajan S, Galley HF. Melatonin treatment has consistent but transient beneficial effects on sleep measures and pain in patients with severe chronic pain: the DREAM-CP randomised controlled trial. Br J Anaesth. 2024;132(4):725-734. doi:10.1016/j.bja.2024.01.012
Overview
Disturbed sleep is often reported in those who suffer chronic pain. This randomized, blinded crossover study examined how a specific melatonin supplement, Circadin™, (2 mg) affected sleep and pain levels in chronic pain patients.
While melatonin (Circadin™) did not significantly improve sleep disturbances caused by pain, however, sleep parameters improved.
SNHI’s Advisory Council comments/takeaway from the article
This study was a single-center, randomized, double-blinded, placebo-controlled, crossover trial using 2 mg of melatonin. There were multiple improvements in sleep, as measured by various questionnaires, and small but significant improvements in pain scores. Despite the favorable outcomes, many pain studies to date have used 8, 10, and 20 mg of melatonin to reduce self-reported pain levels; therefore, 2 mg may be too conservative for aggressive pain management. Similarly, 2 mg may be too high or too low for optimizing sleep and circadian rhythms. The findings of this study are promising for melatonin’s role in reducing pain and improving sleep parameters when a patient is experiencing pain.
Article summary including Results
Of the 58 participants at the beginning of the trial, 51 completed the trial (20 weeks) with 6 weeks of treatment, 4 weeks of washout, and 6 weeks of placebo. The primary outcome was to assess sleep disturbances after 6 weeks of melatonin treatment, using the Verran and Snyder-Halpern (VSH) scale. Four secondary outcomes included the assessment of sleep quality using the Pittsburg-Sleep Quality Index (PSQI) and the impact on pain using Pain and Sleep Questionnaire (PSQ-3), pain intensity and sleep interference scores using Brief Pain Inventory (BPI), and measurement of daily pain and fatigue scores using Actiwatch.
Based on the VSH scale, there were no significant changes in the primary sleep outcome or sleep disturbance in either 6-week treatment group compared with the placebo.
However, there were significant improvements after 3 weeks in the melatonin treatment group (p<0.001) that were not observed during the placebo treatment time. Also, sleep latency (time to fall asleep) and wake-after-sleep onset scores were improved (p<0.001 and p=0.024, respectively).
Pain and fatigue scores (using the PSQ-3) also showed significant improvements (p<0.001) during the melatonin treatment periods. Likewise, pain and fatigue were also significantly reduced as measured by the scores inputted into the Actiwatch.
Global sleep quality scores increased significantly (p<0.001) after 3 and 6 weeks of melatonin treatment.
Limitations noted by Author(s)
1. Sleep and pain scales are subjective.
2. Low compliance for some participants (40-100%)
3. The Actiwatch that participants wore was confounded for ‘time in bed’ if they were not active and more sedentary.
4. This trial occurred during the pandemic, which cut short the team’s measurements of melatonin serum levels with the removal of in-person visits; blood samples were only collected from the first 18 participants.
5. Participants were recruited at a pain clinic, so they may represent the most severe pain cases since the majority of chronic pain patients are seen in primary care settings.
6. Minor adverse effects were noted, but were considered unrelated to the trial or use of melatonin.
Other limitations noted in this review
None noted.
Article review completed by Mona Fahoum, ND
Content reviewed by Kim Ross, DCN
Date June 10, 2024