Pain
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Randomized Controlled Trial
Pregabalin in severe burn injury pain: a double-blind, randomised placebo-controlled trial.
This randomised, double-blind, placebo-controlled trial assessed the efficacy and tolerability of pregabalin to alleviate the neuropathic component of moderate to severe burn pain. Patients aged 18 to 65 years admitted to a burns unit with a 5% or greater total body surface area burn injury were screened to participate in the trial. Using the Neuropathic Pain Scale (NPS), patients scoring 4 or higher on 'hot' pain or 'sharp' pain were invited to participate. ⋯ There was no significant difference between the pregabalin and placebo treatment groups with respect to opioid consumption, duration of hospital stay, or pain at 6 months. Pregabalin was efficacious and well tolerated in patients after severe burn injury and whose pain was characterised by features of acute neuropathic pain. In this study, pregabalin was well tolerated and significantly reduced several elements of the neuropathic pain scale including hot pain, unpleasantness of the pain, surface pain, and itch, and also significantly reduced procedural pain.
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Randomized Controlled Trial
Tropisetron blocks analgesic action of acetaminophen: a human pain model study.
Because the mechanism underlying the analgesic action of acetaminophen remains unclear, we investigated the possible interaction of acetaminophen with central serotonergic pathways. The effects of acetaminophen, tropisetron, the combination of both drugs, and saline on pain perception and central sensitization in healthy volunteers were compared. Sixteen healthy volunteers were included in this randomized, double-blind, placebo-controlled crossover study. ⋯ In summary, while the combination of acetaminophen and tropisetron showed no analgesic action, each drug administered alone led to decreased pain ratings as compared to saline. In an electrically evoked human pain model, the combination of acetaminophen with tropisetron was free of any analgesic potential. However, when administered on its own, both acetaminophen and tropisetron were mildly analgesic.
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Randomized Controlled Trial
Effects of COX inhibition on experimental pain and hyperalgesia during and after remifentanil infusion in humans.
Opioids may enhance pain sensitivity resulting in opioid-induced hyperalgesia (OIH). Activation of spinal cyclooxygenase may play a role in the development of OIH. The aim of this study was to demonstrate remifentanil-induced postinfusion hyperalgesia in an electrical pain and a cold pain model, and to investigate whether COX-2 (parecoxib) or COX-1 (ketorolac) inhibition could prevent hyperalgesia after remifentanil infusion. ⋯ These results demonstrated OIH in both models, and may suggest that COX-2 inhibition is more important than COX-1 inhibition in reducing hyperalgesia. Remifentanil-induced hyperalgesia was demonstrated for both electrically induced pain and cold-pressor pain. Both parecoxib and ketorolac prevented hyperalgesia in the electrical model, parecoxib to a larger extent.
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Some expert guidelines recommend time-scheduled opioid dosing over pain-contingent dosing for patients receiving chronic opioid therapy (COT). The premise is that time-scheduled dosing results in more stable opioid blood levels and better pain relief, fewer adverse effects, less reinforcement of pain behaviors, and lower addiction risk. We report results of a survey of 1781 patients receiving COT for chronic noncancer pain, in which 967 reported time-scheduled opioid dosing only and 325 reported pain-contingent opioid dosing only. ⋯ Controlled comparative effectiveness research is needed to assess benefits and risks of time-scheduled opioid dosing relative to pain-contingent opioid dosing among COT patients in ambulatory care. Patients with time-scheduled dosing received higher opioid dosage than patients with pain-contingent dosing. Time-scheduled dosing was associated with greater opioid control concerns than pain-contingent dosing.