Articles: opioid.
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Comparative Study
Endogenous opioids regulate glucocorticoid-dependent stress coping strategies in mice.
Coping skills are essential in determining the outcomes of aversive life events. Our research was aimed to elucidate the molecular underpinnings of different coping styles in two inbred mouse strains, C57BL/6J and SWR/J. We compared the influence of a preceding stressor (0.5h of restraint) on behavioral and gene expression profiles between these two strains. ⋯ We found that treatment with a glucocorticoid receptor (GR) agonist (dexamethasone (DEX), 4mg/kg) impaired the consolidation of fear memory in the C57BL/6J mice and that this effect was reversed by OR blockade (naltrexone (NTX), 2mg/kg). In parallel, a glucocorticoid receptor antagonist (mifepristone (MIF), 20mg/kg) reversed the effect of morphine (20mg/kg) on conditioned fear in the C57BL/6J mice. Our results suggest that in mice, stress-coping strategies are determined by opioid-dependent mechanisms that modulate activity of the HPA axis.
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Sleep fragmentation has been linked to poor pain tolerance and lowered pain threshold. Little evidence exists on whether continuous positive airway pressure (CPAP) adherence in veterans with obstructive sleep apnea (OSA) who are taking opioids for non-malignant pain would ameliorate pain and reduce consumption of opioids. ⋯ CPAP treatment did not reduce pain intensity or consumption of opioids in veterans with chronic pain who have coexisting OSA. CPAP adherence was lower in opioid-treated veterans with OSA compared to opioid-free veterans with OSA. Pain intensity was the only determinant of CPAP adherence. Future studies are needed to evaluate pain management program on adherence to CPAP.
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Chronic pain is a common condition in the general population. However, large epidemiologic studies examining the role of pain in the deterioration of kidney function, development of chronic kidney disease, and risk for death are lacking. ⋯ We observed a high prevalence of pain and analgesic prescription in the US veteran population with normal eGFRs. Pain was associated with a higher incidence of eGFRs<60mL/min/1.73m(2), faster kidney function decline, and higher mortality.
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Controlled Clinical Trial
Expectancy Effects on Conditioned Pain Modulation Are Not Influenced by Naloxone or Morphine.
Recent studies suggest that participant expectations influence pain ratings during conditioned pain modulation testing. The present study extends this work by examining expectancy effects among individuals with and without chronic back pain after administration of placebo, naloxone, or morphine. ⋯ The present findings confirm that expectancy is an important contributor to conditioned pain modulation effects, and therefore significant caution is needed when interpreting findings that do not account for this individual difference. Opioid mechanisms do not appear to be involved in these expectancy effects.
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Mechanically ventilated patients may receive more sedation during the night than during the day, potentially delaying extubation. We compared nighttime and daytime benzodiazepine and opioid administration in adult patients enrolled in a multicenter sedation trial comparing protocolized sedation alone or protocolized sedation combined with daily sedation interruption; and we evaluated whether nighttime and daytime doses were associated with liberation from mechanical ventilation. ⋯ Patients received higher doses of opioids and benzodiazepines at night. Higher nighttime doses were associated with SBT failure and delayed extubation.