Plasma concentrations of the enantiomers of methadone and therapeutic response in methadone maintenance treatment

Details

Serval ID
serval:BIB_D9AFA531780D
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Plasma concentrations of the enantiomers of methadone and therapeutic response in methadone maintenance treatment
Journal
Drug and alcohol dependence
Author(s)
Eap C.B., Bourquin M., Martin J., Spagnoli J., Livoti S., Powell K., Baumann P., Déglon J.
ISSN
0376-8716
Publication state
Published
Issued date
2000
Peer-reviewed
Oui
Volume
61
Number
1
Pages
47-54
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't - Publication Status: ppublish
Abstract
Methadone is a 50:50 mixture of two enantiomers and (R)-methadone accounts for the majority of its opioid effect. The aim of this study was to determine whether a blood concentration of (R)-methadone can be associated with therapeutic response in addict patients in methadone maintenance treatment. Trough plasma concentrations of (R)-, (S)- and (R,S)-methadone were measured in 180 patients in maintenance treatment. Therapeutic response was defined by the absence of illicit opiate or cocaine in urine samples collected during a 2-month period prior to blood sampling. A large interindividual variability of (R)-methadone concentration-to-dose-to-weight ratios was found (mean, S.D., median, range: 112, 54, 100, 19-316 ng x kg/ml x mg). With regard to the consumption of illicit opiate (but not of cocaine), a therapeutic response was associated with (R)- (at 250 ng/ml) and (R,S)-methadone (at 400 ng/ml) but not with (S)-methadone concentrations. A higher specificity was calculated for (R)- than for (R,S)-methadone, as the number of non-responders above this threshold divided by the total number of non-responders was higher for (R,S)-methadone (19%) than for (R)-methadone (7%). The results support the use of therapeutic drug monitoring of (R)-methadone in cases of continued intake of illicit opiates. Due to the variability of methadone concentration-to-dose-to-weight ratios, theoretical doses of racemic methadone could be as small as 55 mg/day and as large as 921 mg/day to produce a plasma (R)-methadone concentration of 250 ng/ml in a 70-kg patient. This demonstrates the importance of individualizing methadone treatment.
Keywords
Adult, Drug Administration Schedule, Female, Humans, Male, Methadone, Middle Aged, Narcotics, Opioid-Related Disorders, Sensitivity and Specificity, Stereoisomerism
Pubmed
Web of science
Create date
10/03/2008 10:54
Last modification date
20/08/2019 15:59
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