Linked Life Data

7543969

Source:http://linkedlifedata.com/resource/pubmed/id/7543969

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1995-9-20
pubmed:abstractText
Risperidone is a recently introduced neuroleptic distinguished by a decreased incidence of extrapyramidal side effects (EPS). The mechanism of its low EPS is unclear. Since it has been shown that EPS is related to the level of D2 receptor occupancy, we studied nine patients receiving 2-6 mg/day of risperidone using [11C]-raclopride PET scans in order to determine the in vivo D2 receptor binding characteristics of risperidone. The mean level of receptor occupancy was 66% at 2 mg; 73% at 4 mg; and 79% at 6 mg. Three patients, those with the highest receptor occupancies, exhibited mild EPS, though none required anitparkinsonian medications. Our results suggest that at doses of 4-6 mg the in vivo D2 receptor occupancy of risperidone is similar to that of typical neuroleptics and higher than that of clozapine. This would suggest that the EPS benefits of risperidone cannot be explained by a low D2 binding but may be related to its high 5-HT2 affinity. However, the emergence of EPS at higher levels of D2 receptor occupancy, in this study and in previous clinical trials, would suggest that risperidone's high 5-HT2 affinity provides only a relative protection from EPS. And once the D2 occupancy exceeds a certain threshold this 'relative' 5-HT2-mediated protection from EPS may be lost.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0024-3205
pubmed:author
pubmed:issnType
Print
pubmed:volume
57
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
PL103-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
The D2 dopamine receptor occupancy of risperidone and its relationship to extrapyramidal symptoms: a PET study.
pubmed:affiliation
Schizophrenia Research Program, Clarke Institute of Psychiatry, University of Toronto, ON, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't