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Opioid resistance: ‘wind up’
•
Allodynia
:
altered sensitivity of central neurones
with relatively minor pain being perceived as
severe pain
•
NMDA (N-methyl-D-aspartate receptors mediate
allodynia
•
NMDA receptor antagonists eg methadone or
ketamine may be of value in resetting opoioid
tolerance: hence work best
with
morphine