Experimental sleep disruption attenuates morphine analgesia: findings from a randomized trial and implications for the opioid abuse epidemic.

Preclinical studies demonstrate that sleep disruption diminishes morphine analgesia and modulates reward processing. We sought to translate these preclinical findings to humans by examining whether sleep disruption alters morphine's analgesic and hedonic properties. We randomized 100 healthy adults to receive morphine versus placebo after two nights of undisturbed sleep (US) and two nights of forced awakening (FA) sleep disruption. Sleep conditions were counterbalanced, separated by a two-week washout. The morning after both sleep conditions, we tested cold pressor pain tolerance before and 40-min after double-blind injection of .08 mg/kg morphine or placebo. The primary outcome was the analgesia index, calculated as the change in cold pressor hand withdrawal latency (HWL) before and after drug injection. Secondary outcomes were ratings of feeling "high," drug "liking," and negative drug effects. We found a significant sleep condition by drug interaction on the analgesia index (95% CI - 0.57, - 0.001). After US, subjects receiving morphine demonstrated significantly longer HWL compared to placebo (95% CI 0.23, 0.65), but not after FA (95% CI - 0.05, 0.38). Morphine analgesia was diminished threefold under FA, relative to US. After FA, females (95% CI - 0.88, - 0.05), but not males (95% CI - 0.23, 0.72), reported decreased subjective "high" effects compared to US. After FA, females (95% CI 0.05, 0.27), but not males (95% CI - 0.10, 0.11), administered morphine reported increased negative drug effects compared to US. These data demonstrate that sleep disruption attenuates morphine analgesia in humans and suggest that sleep disturbed males may be at greatest risk for problematic opioid use.

Daily Opioid Use Fluctuates as a Function of Pain, Catastrophizing, and Affect in Patients With Sickle Cell Disease: An Electronic Daily Diary Analysis.

Chronic opioid therapy is a common treatment regimen for patients with sickle cell disease (SCD), a chronically painful recessive hemoglobinopathy. The collective risk profile of chronic opioid therapy necessitates an understanding of which pain-related factors, such as affect and pain catastrophizing, are associated with the ebbs and flows of opioid use in daily life, a topic that has received very little attention among patients with any type of chronically painful condition, including SCD. We therefore investigated the variability of day-to-day patterns of short- and long-acting opioid use and their associations with pain and pain-related cognitive and affective processes in daily life among patients with SCD using a nightly electronic diary (N = 45). Opioid use was self-reported and converted into oral morphine equivalents for analysis, which was conducted with mixed effects modeling. Results indicated that greater pain and pain catastrophizing were associated with greater use of short-acting opioids, and negative affect was associated with greater use of long-acting opioids. Additionally, the association of pain and short-acting opioid use was moderated by pain catastrophizing, showing that opioid use was elevated when patients catastrophized about their pain, even if they reported low levels of pain. These findings suggest that monitoring pain-related cognitive and affective variables may be a useful approach to understanding risk for problematic opioid use in patients with daily pain. PERSPECTIVE: The present study shows that pain and pain-related cognitive and affective variables are associated with daily variation in prescription opioid use in SCD. The findings may have broad implications for tracking and defining risk for prescription opioid misuse in patients with daily pain.