Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3-4
pubmed:dateCreated
1996-8-8
pubmed:abstractText
The present study was designed to investigate the possible role of some alpha 2-agonists in the phenomenon of tolerance to opioid-induced antinociception. To do so, the alpha 2-agonists were tested alone and in combination with opioids in naive and repeatedly fentanyl-treated rats in the tail withdrawal reaction (TWR) test. Under the treatment schedule used, rats became tolerant to fentanyl and cross-tolerance was observed with other opioids. The alpha 2-agonists alone were inactive in opioid naive and repeatedly fentanyl-treated rats. The potentiating interaction between the alpha 2-agonists and fentanyl in naive animals diminished considerably after the repeated fentanyl treatment. Adding an alpha 2-agonist to high doses of fentanyl during repeated treatment resulted in a complete tolerance to both compounds. Using lower, but equipotent antinociceptive drug combinations of alpha 2-agonists and opioids, resulted in less tolerance. Alpha 2-agonists are thus unable to directly overcome tolerance to the antinociceptive activity of fentanyl in tolerant animals. Nevertheless, by lowering the dose of the opioid for an equipotent antinociceptive activity, alpha 2-agonists are able to delay the onset of tolerance, probably based on the concept of opioid receptor sparing.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0001-5164
pubmed:author
pubmed:issnType
Print
pubmed:volume
46
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
141-52
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Can alpha 2-adrenoceptor agonists reverse or prevent tolerance to the antinociceptive activity of opioids in rats?
pubmed:affiliation
Cliniques Universitaires Saint Luc, Department of Anaesthesiology, Bruxlles, Belgium.
pubmed:publicationType
Journal Article