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
Long-term effects of routine morphine infusion in mechanically ventilated neonates on children's functioning: five-year follow-up of a randomized controlled trial.
Newborns on ventilatory support often receive morphine to induce analgesia. Animal experiments suggest that this may impair subsequent cognitive and behavioral development. There are sparse human data on long-term effects of neonatal morphine. ⋯ However, scores on one IQ subtest, "visual analysis," were significantly negatively related to having received morphine and to open-label morphine consumption the first 28 days. The finding of a significant effect of morphine on the "visual analysis" IQ subtest calls for follow-up at a later age focusing on the higher-order neurocognitive functions. Morphine received in the neonatal period has negative effects on the child's cognitive functioning at the age of 5 years which warrants follow-up at a later age.
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Glycine inhibitory dysfunction provides a useful experimental model for studying the mechanism of dynamic mechanical allodynia, a widespread and intractable symptom of neuropathic pain. In this model, allodynia expression relies on N-methyl-d-aspartate receptors (NMDARs), and it has been shown that astrocytes can regulate their activation through the release of the NMDAR coagonist d-serine. Recent studies also suggest that astrocytes potentially contribute to neuropathic pain. ⋯ These results suggest the following scenario: removal of glycine inhibition makes tactile stimuli able to activate astrocytes; activated astrocytes may provide d-serine to enable NMDAR activation and thus allodynia. Such a contribution of astrocytes to pathological pain fuels the emerging concept that astrocytes are critical players in pain signaling. Glycine disinhibition makes tactile stimuli able to activate astrocytes, which may provide d-serine to enable NMDA receptor activation and thus allodynia.
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Distinct developmental trajectories for neck disability and posttraumatic stress disorder (PTSD) symptoms after whiplash injury have recently been identified. This study aimed to identify baseline predictors of membership to these trajectories and to explore their dual development. In a prospective study, 155 individuals with whiplash were assessed at <1 month, 3, 6, and 12 months postinjury. ⋯ These findings support the proposal of links between the development of chronic neck related disability and PTSD after whiplash injury. Developmental trajectories of disability and posttraumatic stress disorder (PTSD) after whiplash injury are mostly in synchrony, and similar factors predict their membership. This suggests links between the development of chronic neck pain-related disability and PTSD.
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Chronic pain is a common reason for medical visits, but prevalence estimates vary between studies and have rarely included drug treatment data. This study aimed to examine characteristics of chronic pain and its relation to demographic and health factors, and factors associated with treatment of pain with opioid analgesics. A chronic pain module was added to the 2007 Kansas Behavioral Risk Factor Surveillance System (response rate = 61%). ⋯ S. A. Overall, 45.7% of people who take prescription drugs for chronic pain reported taking opioid analgesics.