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Opioid-induced hyperalgesia and incisional pain
1Veterans Affairs, Palo Alto Health Care System and Department of Anesthesiology, Stanford University, Palo Alto, California 94304, USA.
Anesthesia and Analgesia
|June 29, 2001
Summary
Opioid-induced hyperalgesia (OIH) can worsen pain after surgery. Chronic opioid use followed by abrupt discontinuation leads to increased pain sensitivity, which is additive with incisional pain.
Area of Science:
- Neuroscience
- Pharmacology
- Pain Research
Background:
- Opioids are clinically vital for pain management.
- Opioid-induced hyperalgesia (OIH) is a paradoxical increase in pain sensitivity following opioid administration.
- OIH can occur upon abrupt opioid tapering or discontinuation.
Purpose of the Study:
- To investigate the effects of chronic opioid administration and withdrawal on pain sensitivity in a rat model.
- To determine if OIH is additive with incisional pain.
- To explore the role of naloxone in modulating OIH and incisional pain.
Main Methods:
- Rats received morphine via osmotic minipumps for 6 days.
- Thermal hyperalgesia and mechanical allodynia were assessed after morphine cessation.
- The impact of OIH on incisional pain was evaluated.
- Naloxone was administered chronically before or acutely after incision.
Main Results:
- Morphine administration induced thermal hyperalgesia and mechanical allodynia post-cessation.
- OIH effects were additive with incisional pain.
- Chronic naloxone administration before incision reduced hyperalgesia and allodynia.
- Acute naloxone administration post-incision exacerbated hyperalgesia and allodynia.
Conclusions:
- Chronic opioid administration followed by abrupt cessation can induce hyperalgesia.
- Opioid-induced hyperalgesia and incisional pain are additive in rats.
- Preoperative opioid use must be considered to prevent excessive postoperative pain.
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