Fentanyl Ultra Low Doses Effects on the Nociceptive Threshold
Status:
Completed
Trial end date:
2007-08-01
Target enrollment:
Participant gender:
Summary
Exaggerated pain and hyperalgesia are major issues after surgery and can lead to chronic
pain. Opioid are parts of pain sensitization processes but remain absolutely necessary in the
intraoperative period. NMDA receptor antagonists succeed in reducing this pain sensitization
process. Recent studies show that in pain and opioid-experienced rats (POER) fentanyl ultra
low doses do not induce analgesia, as observed in naive rats, but hyperalgesia. This is the
first demonstration that a drug can induce opposite effect depending on individual history.
We also observed a strong correlation between this hyperalgesic response in POER and the
intensity of hyperalgesia they develop later, after inflammatory or surgical pain. The main
aim of this study is to measure the dose effect response to fentanyl "ultra low doses" on
human volunteer's nociceptive threshold, to determine if such an opposite response profile
can be revealed.