Predictors of Prolonged Opioid Use After Initial Prescription for Acute Musculoskeletal Injuries in Adults A Systematic Review and Meta-analysis of Observational Studies
ANNALS OF INTERNAL MEDICINE
Authors: Riva, John J.; Noor, Salmi T.; Wang, Li; Ashoorion, Vahid; Foroutan, Farid; Sadeghirad, Behnam; Couban, Rachel; Busse, Jason W.
Abstract
Background: Opioids are frequently prescribed for acute musculoskeletal injuries and may result in long-term use and consequent harms. Purpose: To explore factors associated with persistent opioid use after its prescription for acute musculoskeletal injury. Data Sources: Searches of multiple electronic databases, without language restrictions, from inception to 6 January 2020, and reference lists of selected articles. Study Selection: Observational studies of adults with opioid prescriptions for outpatient acute musculoskeletal injuries, in an adjusted model, that explored risk factors for prolonged use. Data Extraction: 6 reviewers, working in pairs, independently extracted data, rated the quality of studies, and evaluated the certainty of evidence. Data Synthesis: 14 cohorts with 13 263 393 participants were included. The overall prevalence of prolonged opioid use after musculoskeletal injury for high-risk populations (that is, patients receiving workers' compensation benefits, Veterans Affairs claimants, or patients with high rates of concurrent substance use disorder) was 27% (95% CI, 18% to 37%). The prevalence among low-risk populations was 6% (CI, 4% to 8%; P for interaction < 0.001). Moderate-certainty evidence showed increased odds of persistent opioid use with older age (absolute risk increase [ARI] for every 10-year increase, 1.1% [CI, 0.7% to 1.5%]) and physical comorbidity (ARI, 0.9% [CI, 0.1% to 1.7%]). Low-certainty evidence suggested increased risk for persistent opioid use with past or current substance use disorder (ARI, 10.5% [CI, 4.2% to 19.8%]), prescriptions lasting more than 7 days (median ARI, 4.5%), and higher morphine milligram equivalents per day. Limitation: Sparse, heterogeneous data with suboptimal adjustment for potential confounders. Conclusion: Avoiding prescribing opioids for acute musculoskeletal injuries to patients with past or current substance use disorder, and restricting duration to 7 days or less and using lower doses when they are prescribed, are potentially important targets to reduce rates of persistent opioid use.
Serotonin and noradrenaline modulate chronic itch processing in mice
EUROPEAN JOURNAL OF PHARMACOLOGY
Authors: Miyahara, Yu; Funahashi, Hideki; Naono-Nakayama, Rumi; Haruta-Tsukamoto, Ayaka; Muroi, Chiyo; Kogoh, Yoichiro; Nishimori, Toshikazu; Ishida, Yasushi
Abstract
The roles of serotonin and noradrenaline in the modulation of chronic pruriceptive processing currently remain unclear. To clarify the contribution of serotonin and noradrenaline to chronic itch, the effects of the administration of antidepressants or noradrenaline reuptake inhibitors were evaluated in the present study. A pretreatment with milnacipran, a serotonin and noradrenaline reuptake inhibitor, and mirtazapine, a noradrenergic and specific serotonergic antidepressant, attenuated the induction of spontaneous scratching behavior in mice with chronic itch. The administration of a serotonin reuptake inhibitor, such as fluvoxamine and paroxetine, but not escitalopram, or a noradrenaline reuptake inhibitor, such as atomoxetine and nisoxetine, ameliorated the induction of spontaneous scratching behavior in mice with chronic itch. Furthermore, this attenuation was reversed by the administration of yohimbine, a selective alpha(2)-adrenoceptor antagonist, or methysergide, a nonselective serotonin receptor antagonist. These results suggest that elevated serotonin and noradrenaline levels are involved in the attenuation of scratching behavior induced by chronic itch, and serotonin receptors and an alpha(2)-adrenoceptor play a crucial role in chronic pruriceptive processing.