Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.13/916039

OpenURL Link
Title
Cannabis and benzodiazepines as determinants of methadone trough plasma concentration variability in maintenance treatment: a transnational study
Author/Creator
Hallinan, Richard;  Crettol, Séverine;  Somogyi, Andrew A.;  Eap, Chin B.;  Agho, Kingsley;  Attia, John;  Besson, Jacques;  Croquette-Krokar, Marina;  Hämmig, Robert;  Déglon, Jean-Jacques;  Byrne, Andrew;  Ray, John
Institution
The University of Newcastle. Faculty of Health, School of Medicine and Public Health
Description
Purpose: To assess tobacco, alcohol, cannabis and benzodiazepine use in methadone maintenance treatment (MMT) as potential sources of variability in methadone pharmacokinetics. Methods: Trough plasma (R)- and (S)-methadone concentrations were measured on 77 Australian and 74 Swiss MMT patients with no additional medications other than benzodiazepines. Simple and multiple regression analyses were performed for the primary metric, plasma methadone concentration/dose. Results: Cannabis and methadone dose were significantly associated with lower 24-h plasma (R)- and (S)-methadone concentrations/dose. The models containing these variables explained 14–16% and 17–25% of the variation in (R)- and (S)-methadone concentration/dose, respectively. Analysis of 61 patients using only CYP3A4 metabolised benzodiazepines showed this class to be associated with higher (R)-concentration/dose, which is consistent with a potential competitive inhibition of CYP3A4. Conclusion: Cannabis use and higher methadone doses in MMT could in part be a response to — or a cause of — more rapid methadone clearance. The effects of cannabis and benzodiazepines should be controlled for in future studies on methadone pharmacokinetics in MMT.
Relation
European Journal of Clinical Pharmacology Vol. 65, Issue 11, p. 1113-1120
Publisher Link
http://dx.doi.org/10.1007/s00228-009-0706-8
Date
2009
Publisher
Springer
Keyword(s)
benzodiazepine;  cannabis;  drug interaction;  enantiomer;  methadone;  MMT;  pharmacokinetics
Resource Type
journal article
Identifier
http://hdl.handle.net/1959.13/916039
Identifier
ISSN:0031-6970
Reviewed
Reviewed
49 Visitors 53 Hits 0 Downloads
Save/E-mail Citation
Citation Format
E-mail Address
Subject
"European Journal of Clinical Pharmacology"
 
OR