Drug Metabolism Letters

Author(s): Javier Esteban, Maria de la Cruz Pellin, Carmen Gimeno, Jose Barril, Jesus Gimenez, Eva Mora and Adolfo G. Garcia-Perez

DOI: 10.2174/187231208786734067

Cite As
Increase of R-/S-Methadone Enantiomer Concentration Ratio in Serum of Patients Treated with Either Nevirapine or Efavirenz

Page: [269 - 274] Pages: 6

  • * (Excluding Mailing and Handling)

Abstract

An increased methadone enantiomer ratio (R/S) was associated to both nevirapine (179%, n=5) and efavirenz (36%, n=9) treatments when compared with that of controls (n=52). Additionally, in four follow-up patients, both R- and S-methadone normalized concentrations decreased (19%-93%) while R/S increased (22%-314%) following nevirapine/ efavirenz treatment. R/S decreased (42%) after non-compliance with efavirenz treatment. Therefore, the methadonemaintenance- treatment outcome should be evaluated when patients are treated with drugs which are supposed to induce CYP3A4 and CYP2B6 isoforms.

Keywords: Methadone, nevirapine, efavirenz, CYP3A4, CYP2B6, hepatitis C Virus