Pain
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Recent studies suggest that longer durations of opioid use, independent of maximum morphine equivalent dose (MED) achieved, is associated with increased risk of new-onset depression (NOD). Conversely, other studies, not accounting for duration, found that higher MED increased probability of depressive symptoms. To determine whether rate of MED increase is associated with NOD, a retrospective cohort analysis of Veterans Health Administration data (2000-2012) was conducted. ⋯ Faster rates of MED escalation contribute to NOD, independent of maximum dose, pain, and total opioid duration. Dose escalation may be a proxy for loss of control or undetected abuse known to be associated with depression. Clinicians should avoid rapid dose increase when possible and discuss risk of depression with patients if dose increase is warranted for pain.
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Cutaneous inflammation alters the function of primary afferents and gene expression in the affected dorsal root ganglia (DRG). However, specific mechanisms of injury-induced peripheral afferent sensitization and behavioral hypersensitivity during development are not fully understood. Recent studies in children suggest a potential role for growth hormone (GH) in pain modulation. ⋯ These effects may be mediated through an upregulation of insulin-like growth factor 1 receptor (IGFr1) as GH modulated the transcriptional output of IGFr1 in DRG neurons in vitro and in vivo. Afferent-selective knockdown of IGFr1 during inflammation also prevented the observed injury-induced alterations in cutaneous afferents and behavioral hypersensitivity similar to that after GH pretreatment. These results suggest that GH can block inflammation-induced nociceptor sensitization during postnatal development leading to reduced pain-like behaviors, possibly by suppressing the upregulation of IGFr1 within DRG.
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Persons with Alzheimer disease (AD) commonly present with chronic nonmalignant pain, but long-term use of opioids among this population has not been studied previously. Our aim was to investigate the prevalence of long-term (≥180 days) use of opioids for nonmalignant pain and associated factors among community-dwelling persons with AD and to compare the prevalence with a matched cohort without AD. The Medication use and Alzheimer's disease (MEDALZ) cohort was used for this study, comprising all community-dwelling persons diagnosed with AD in Finland during 2005 to 2011 and their matched comparison persons without AD. ⋯ Factors associated with long-term opioid use included AD, age ≥80 years, female sex, rheumatoid arthritis, osteoporosis, low socioeconomic position, history of substance abuse, and long-term benzodiazepine use. Prevalence of long-term opioid use was somewhat similar among both groups. Among persons with AD, long-term opioid use was strongly associated with transdermal opioids.
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Treatments for chronic pain are inadequate, and new options are needed. Nonpharmaceutical approaches are especially attractive with many potential advantages including safety. Light therapy has been suggested to be beneficial in certain medical conditions such as depression, but this approach remains to be explored for modulation of pain. ⋯ Green LED exposure also reversed thermal and mechanical hyperalgesia in rats with spinal nerve ligation. Pharmacological and proteomic profiling of dorsal root ganglion neurons from green LED-exposed rats identified changes in calcium channel activity, including a decrease in the N-type (CaV2.2) channel, a primary analgesic target. Thus, green LED therapy may represent a novel, nonpharmacological approach for managing pain.