Articles: hyperalgesia.
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Reg Anesth Pain Med · Jul 2012
Sciatic nerve block fails in preventing the development of late stress-induced hyperalgesia when high-dose fentanyl is administered perioperatively in rats.
: Sciatic nerve block fails in preventing the development of late stress-induced hyperalgesia (SIH) when high-dose fentanyl is administered perioperatively in rats. ⋯ Perioperative use of long-lasting RA reduced both acute postoperative hyperalgesia and the development of long-term pain vulnerability. However, high doses of fentanyl for intraoperative analgesia induce central sensitization that cannot be reversed by using long-lasting RA.
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Anesthesia and analgesia · Jul 2012
Comparative StudyThe efficacy of morphine, pregabalin, gabapentin, and duloxetine on mechanical allodynia is different from that on neuroma pain in the rat neuropathic pain model.
It has been reported that <50% of neuropathic pain patients are satisfactorily treated with drugs. It is possible that this lack of efficacy of drugs on neuropathic pain might be due to the drugs prescribed, regardless of the origin of pain. We compared the efficacy of orally administered morphine, pregabalin, gabapentin, and duloxetine on mechanical allodynia with that on neuroma pain using the tibial neuroma transposition (TNT) model. ⋯ These data indicate that the potency of morphine and the efficacy of pregabalin, gabapentin, and duloxetine on mechanical allodynia are different from those on neuroma pain and that combination therapy is one of different therapeutic choices for the treatment of neuropathic pain.
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N-palmitoyl-ethanolamine (PEA) is an endogenous substance that was first identified in lipid tissue extracts. It has been classified as a CB(2) receptor agonist. Exogenous PEA has the potential to become a valid treatment for neuropathic and inflammatory pain. ⋯ In addition, the dosage of nitrite in the homogenized paw, as determined by colorimetric assay, indicated that exogenous PEA is able to induce NO release. The soluble guanylyl cyclase inhibitor ODQ antagonized the PEA effect, whereas the cGMP-phosphodiesterase inhibitor zaprinast potentiated the antinociceptive effect of low-dose PEA. This study provides evidence that PEA activates nNOS, thus initiating the NO/cGMP pathway and inducing peripheral antinociceptive effects.
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Pharmacological reviews · Jul 2012
ReviewHuman experimental pain models for assessing the therapeutic efficacy of analgesic drugs.
Pain models in animals have shown low predictivity for analgesic efficacy in humans, and clinical studies are often very confounded, blurring the evaluation. Human experimental pain models may therefore help to evaluate mechanisms and effect of analgesics and bridge findings from basic studies to the clinic. The present review outlines the concept and limitations of human experimental pain models and addresses analgesic efficacy in healthy volunteers and patients. ⋯ Assessment with neurophysiologic methods and imaging is valuable as a supplement to psychophysical methods and can increase sensitivity. The models need to be designed with careful consideration of pharmacological mechanisms and pharmacokinetics of analgesics. Knowledge obtained from this review can help design experimental pain studies for new compounds entering phase I and II clinical trials.
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Arch Orthop Trauma Surg · Jul 2012
Case ReportsKlippel-Trenaunay syndrome: a rare cause of disabling pain after a femoral fracture.
Klippel-Trenaunay syndrome (KTS) is characterized by a cutaneous vascular nevus of the involved extremity, as well as bone and soft tissue hypertrophy of the extremity and venous malformations. We present the case of a 52-year-old man with a femoral fracture and a history of haemangiomas, limb bone hypertrophy and varicosity. ⋯ According to our knowledge, this is the second case of KTS managed for femoral fracture. Unlike the previous report in literature, in this case a severe disabling neuropathic pain complicated the clinical management.