Abstract
The fentanyl derivative mirfentanil has a novel set of behavioral effects in non-humans including low-efficacy opioid actions and non-opioid antinociceptive actions. This study evaluated the rate decreasing effects of mirfentanil, morphine, naltrexone and ketamine in pigeons both prior to and during a period of chronic treatment with mirfentanil (3.2-17.8 mg/kg/day). Daily treatment with mirfentanil did not modify the rate-decreasing effects of mirfentanil or ketamine; however, daily treatment decreased sensitivity to the rate decreasing effects of morphine and increased sensitivity to naltrexone. These results demonstrate a lack of tolerance to an apparently non-opioid action (rate-decreasing effect) of mirfentanil, which might predict a lack of tolerance to the non-opioid antinociceptive actions of this compound. These results further indicate that cross-tolerance (to morphine) and dependence (increased sensitivity to naltrexone) can occur in the absence of tolerance (to mirfentanil).
Original language | English (US) |
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Pages (from-to) | 543-547 |
Number of pages | 5 |
Journal | Behavioural pharmacology |
Volume | 10 |
Issue number | 5 |
DOIs | |
State | Published - 1999 |
Externally published | Yes |
Keywords
- Dependence
- Mirfentanil
- Morphine
- Non-opioid
- Opioid
- Pigeon
- Rate-decreasing
- Tolerance
ASJC Scopus subject areas
- Pharmacology
- Psychiatry and Mental health