Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2005-11-18
pubmed:abstractText
The opioid antagonist nalmefene offers an alternative to traditional pharmacological treatments for alcoholism. The present study was designed to investigate the relationship between nalmefene plasma concentration and central mu-opioid receptor occupancy after a clinically effective dose (20 mg, orally). Pharmacokinetics and mu-opioid receptor occupancy of nalmefene after single and repeated dosing over 7 days was studied in 12 healthy subjects. Serial blood samples were obtained after both dosings, and pharmacokinetic parameters for nalmefene and main metabolites were determined. Central mu-opioid receptor occupancy of nalmefene was measured with positron emission tomography (PET) and [(11)C]carfentanil at four time points (3, 26, 50, 74 h) after both dosings. Nalmefene was rapidly absorbed in all subjects. The mean t(1/2) of nalmefene was 13.4 h after single and repeated dosing. The accumulation of nalmefene and its main metabolites in plasma during the repeated dosing period was as expected for a drug with linear pharmacokinetics, and steady-state was reached for all analytes. Both nalmefene dosings resulted in a very high occupancy at mu-opioid receptors (87-100%), and the decline in the occupancy was similar after both dosings but clearly slower than the decline in the plasma concentration of nalmefene or metabolites. High nalmefene occupancy (83-100%) persisted at 26 h after the dosings. The prolonged mu-opioid receptor occupancy by nalmefene indicates slow dissociation of the drug from mu-opioid receptors. These results support the rational of administering nalmefene when needed before alcohol drinking, and they additionally suggest that a high mu-opioid receptor occupancy can be maintained when nalmefene is taken once daily.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0893-133X
pubmed:author
pubmed:issnType
Print
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2245-53
pubmed:dateRevised
2011-5-18
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Prolonged central mu-opioid receptor occupancy after single and repeated nalmefene dosing.
pubmed:affiliation
Clinical Research Services Turku (CRST), University of Turku, FIN-20521 Turku, Finland.
pubmed:publicationType
Journal Article, Clinical Trial, Research Support, Non-U.S. Gov't