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NMDA-receptor antagonists and opioid receptor interactions as related to analgesia and tolerance

D D Price1, D J Mayer, J Mao

  • 1Department of Oral and Maxillofacial Surgery, University of Florida, USA.

Journal of Pain and Symptom Management
|February 25, 2000
PubMed

Insights

Combining NMDA-receptor antagonists with analgesics may enhance pain relief and prevent opioid tolerance. This approach shows promise for improved pain management by blocking hyperalgesia and tolerance, as supported by preclinical studies.

Area of Science:

  • Neuroscience
  • Pharmacology
  • Pain Research

Background:

  • Opioid receptors and N-methyl-D-aspartate (NMDA) receptors are implicated in pain signaling.
  • Evidence suggests a potential interaction between these receptor systems in the dorsal horn.

Purpose of the Study:

  • To investigate the interaction between NMDA receptor and opioid receptor mechanisms in pain pathways.
  • To test the hypothesis that NMDA receptor antagonism can block opioid tolerance and hyperalgesia.

Main Methods:

  • Utilized a model system to explore the interplay of NMDA and opioid receptors in nociceptive neurons.
  • Evaluated the effects of NMDA-receptor antagonists on opioid-induced analgesia, tolerance, and hyperalgesia in preclinical models.

Main Results:

  • Findings support the model that NMDA and opioid receptor mechanisms overlap in dorsal horn neurons.
  • Opioid tolerance was associated with hyperalgesia, and both were blocked by NMDA-receptor antagonists.
  • Preclinical studies demonstrated that combining NMDA-receptor antagonists with analgesics increased analgesic potency.

Conclusions:

  • NMDA receptor antagonism offers a strategy to prevent opioid tolerance and dependence.
  • Co-administration of NMDA-receptor antagonists with analgesics may enhance pain management and increase potency.
  • Nontoxic NMDA-receptor antagonists show practical utility when combined with various analgesic drugs.

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