Elvitegravir + Methadone = Unknown or no reaction

Effect on Concentration

Elvitegravir
No change
Applies within class?
No
Methadone
No change
Applies within class?
No

Pharmacologic Effects

Elvitegravir
Effect
N/A
Applies within class?
No
Methadone
Effect
N/A
Applies within class?
No

Interaction History

N/A

Last Updated 18-Jul-2018

Summary

Sources

Elvitegravir versus Methadone ^

Study Design

A cohort study was conducted to assess the effects of Methadone on the pharmacokinetics of Elvitegravir/Cobicistat (EVG/co). Participants were healthy adults aged 22 to 55 years old. A total of 12 participants were enrolled and 11 participants completed the study. Participants received an individualized stable dose of Methadone a minimum of 2 weeks prior to screening for the study. Doses for Methadone ranged from 80mg to 120mg per day. On day 1 of the study, participants received their individualized stable dose of Methadone. On days 2 through 11, EVG/Co (150/150mg) was added once daily to their Methadone regimen. PK samplings were performed over 24 hours. Opioid withdrawal/overdose assessments (standardized pharmacodynamics tests) were conducted day 1 through 11. Data was also provided for both enantiomers of Methadone.

Study Results

Drug AUC GMR (90% CI) Cmax GMR (90% CI) Ctau GMR (90% CI) R-Methadone 107 (96.1-119) 101 (90.8-113) 110 (94.8-128) S-Methadone 100 (89.4-112) 95.9 (86.6-106) 102 (89.2-117) No dose adjustments were needed during the duration of the study. No participant experienced withdrawal or overdose symptoms.

Study Conclusions

Based on the PK data and patient response during the study, co-administration of Methadone and EVG/co showed no clinically significant changes in PK values of any agent. There are no dose adjustments warranted at this time.

References

Bruce RD, Winkle P, Custodio JM, Wei LX, Rhee MS, Kearney BP, Friedland GH. Investigation of the interactions between methadone and elvitegravir-cobicistat in subjects receiving chronic methadone maintenance. Antimicrobial Agents And Chemotherapy . 2013; 12: 6154-6157.