Articles: opioid.
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Randomized Controlled Trial
Cardiorespiratory, sedative and antinociceptive effects of dexmedetomidine alone or in combination with methadone, morphine or tramadol in dogs.
To evaluate the cardiorespiratory, sedative and antinociceptive effects of dexmedetomidine alone or in combination with methadone, morphine or tramadol in dogs. ⋯ The treatments with morphine and methadone added to the dexmedetomidine showed higher sedation scores than the control treatment and the treatment with tramadol added to the dexmedetomidine showed no relevant differences in any of the variables evaluated in the study.
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The use of opioids in surgeries for morbidly obese patients could cause respiratory depression. Therefore, alternative analgesics are needed to improve anesthetic management for obese patients. The objective of this study was to compare the effect of dexmedetomidine and clonidine on pain as well as analgesic consumption at 24 h postoperatively in patients undergoing laparoscopic gastric sleeve. The secondary objective was to compare patients' and surgeons' satisfaction. ⋯ This study concluded that clonidine and dexmedetomidine yielded similar outcomes with a difference in pain and analgesic consumption at 12 h postoperatively.
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Opioids activate glia in the central nervous system in part by activating the toll-like receptor 4 (TLR4)/myeloid differentiation 2 (MD2) complex. TLR4/MD2-mediated activation of glia by opioids compromises their analgesic actions. Glial activation is also hypothesized as pivotal in opioid-mediated reward and tolerance and as a contributor to opioid-mediated respiratory depression. ⋯ Minocycline had no effect on respiratory depression in vitro. Finally, the respiratory depression evoked in anesthetized rats by tail vein infusion of fentanyl was unaffected by subsequent injection of (+)naloxone, but completely reversed by (-)naloxone. These data indicate that neither activation of microglia in preBötC nor TLR4/MD2-activation contribute to opioid-induced respiratory depression.
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Randomized Controlled Trial
Peripheral opioid receptor blockade increases postoperative morphine demands - a randomized, double-blind, placebo-controlled trial.
Experimental studies suggest that a large proportion of opioid analgesia can be mediated by peripheral opioid receptors. This trial examined the contribution of such receptors to clinical analgesia induced by intravenous morphine. We hypothesized that the selective blockade of peripheral opioid receptors by methylnaltrexone (MNX) would increase the patients' demand for morphine to achieve satisfactory postoperative pain relief. ⋯ Secondary endpoints were similar in all groups (P>.05). Thus, a significant proportion of analgesia produced by systemically administered morphine is mediated by peripheral opioid receptors. Drugs that selectively activate such receptors should have the potential to produce powerful clinical pain relief.