Articles: hyperalgesia.
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Int J Clin Pract Suppl · Jul 2002
Randomized Controlled Trial Comparative Study Clinical TrialAnti-hyperalgesic effects of nimesulide: studies in rats and humans.
Nonsteroidal anti-inflammatory drugs (NSAIDs) are frequently used as analgesics. Despite the fact that clinical experience indicates a considerable disparity in the analgesic efficacy of NSAIDs, the animal models of nociception do not allow a clear distinction to be made between the analgesic properties of these agents. In contrast to nociceptive pain, clinical pain is characterised by hyperalgesia. ⋯ Moreover, nimesulide (100 mg) was significantly more effective than rofecoxib (25 mg). Overall, our data demonstrate that NSAIDs may show different anti-hyperalgesic properties. Nimesulide seems to be particularly effective and fast-acting against inflammatory pain.
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Randomized Controlled Trial Clinical Trial
Quantitative and qualitative perceptual analysis of cold dysesthesia and hyperalgesia in fibromyalgia.
Somatosensory perception thresholds, perceived intensity, and quality of perceptions were assessed in 20 women with fibromyalgia syndrome (FMS) and in 20 healthy age-matched female controls. All patients and controls scaled perceived intensity and described perceived quality of randomized thermal (Thermotest) and tactile (von Frey filaments) stimulation. Perceived intensity was scaled by free-number magnitude estimation and interindividual comparability was accomplished by Master Scaling. ⋯ The combination of cold hyperesthesia, cold dysesthesia, and multimodal hyperalgesia suggests a selective pathophysiology at a particular level of integration, possibly in the insular cortex. It is suggested that the aberrations revealed by the supraliminal sensory evaluation may be generic for FMS. Particularly, the aberrations established in all patients for perceived quality and intensity in the cold sensory channel may be an additional diagnostic criterion.
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Randomized Controlled Trial Clinical Trial
Concentration-effect relationships for intravenous alfentanil and ketamine infusions in human volunteers: effects on acute thresholds and capsaicin-evoked hyperpathia.
The authors have extended preclinical studies on pain to human volunteers by examining the effects of intravenous alfentanil and ketamine on acute sensory thresholds andfacilitated processing induced by intradermal capsaicin. Eleven healthy subjects received targeted plasma concentrations of alfentanil, ketamine, and placebo followed by neurosensory testing (thermal and von Frey hair thresholds). After completing the tests at the highest plasma level, intradermal capsaicin was injected into the volar aspect of the left forearm, and the flare response and hyperalgesia to von Frey hair, stroking, and heat were assessed. ⋯ Ketamine significantly decreased capsaicin-induced von Frey hair hyperalgesia. Both drugs resulted in a significant elevation of von Frey hair-induced pain thresholds and a decrease in capsaicin-induced pain. These studies suggest that experimental human pain models may be used to study analgesic pharmacology and may serve as important methods for defining the analgesic efficacy of drugs in phase I clinical trials.
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Reg Anesth Pain Med · Sep 2001
Randomized Controlled Trial Clinical TrialEffect of systemic adenosine on pain and secondary hyperalgesia associated with the heat/capsaicin sensitization model in healthy volunteers.
Adenosine is an endogenous compound that may have analgesic effects. Results from clinical trials are not consistent, however, and there is a need for large-scale, randomized, placebo-controlled studies to clarify the role of adenosine in the treatment of pain states, including acute nociceptive pain and pain involving central sensitization. ⋯ We conclude that adenosine has no effect on acute nociceptive pain induced by heat stimulation or on secondary hyperalgesia induced by heat/capsaicin sensitization in healthy volunteers.
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Acta Anaesthesiol Scand · Sep 2001
Randomized Controlled Trial Clinical TrialEffect of naloxone on primary and secondary hyperalgesia induced by the human burn injury model.
Opioid antagonists may change the responses in models of experimental hyperalgesia. This indicates a possible involvement of the endogenous opioid system in these models. The aim of the present study was to evaluate whether activation of the endogenous opioid system could be demonstrated in the human burn injury model of cutaneous hyperalgesia, using an intravenous challenge with the non-selective opioid antagonist naloxone. ⋯ Activation of an endogenous opioid response following induction of hyperalgesia in human volunteers by a burn injury could not be demonstrated with an intravenous naloxone challenge. These findings suggest that the endogenous opioid response is not a confounding factor in this model.