The Impact of Benzodiazepine Use on Methadone Maintenance Treatment Outcomes

ABSTRACT

The purposes of this study were to examine predictors of benzodiazepine use among methadone maintenance treatment patients, to determine whether baseline benzodiazepine use influenced ongoing use during methadone maintenance treatment, and to assess the effect of ongoing benzodiazepine use on treatment outcomes (i.e., opioid and cocaine use and treatment retention). A retrospective chart review of 172 methadone maintenance treatment patients (mean age = 34.6 years; standard deviation = 8.5 years; 64% male) from January 1997 to December 1999 was conducted. At baseline, 29% were “non-users” (past year) of benzodiazepine, 36% were “occasional users,” and 35% were “regular/problem users.” Regular/problem users were more likely to have started opioid use with prescription opioids, experienced more overdoses, and reported psychiatric comorbidity. Being female, more years of opioid use, and a history of psychiatric treatment were significant predictors of baseline benzodiazepine use. Ongoing benzodiazepine users were more likely to have opioid-positive and cocaine-positive urine screens during methadone maintenance treatment. Only ongoing cocaine use was negatively related to retention. Benzodiazepine use by methadone maintenance treatment patients is associated with a more complex clinical picture and may negatively influence treatment outcomes.

KEYWORDS:

• Methadone maintenance
• benzodiazepines
• opioids
• cocaine
• treatment retention

The authors wish to acknowledge the dedicated work of the clinical staff within the CAMH Methadone Maintenance Treatment program and the CAMH Health Records Department.

This study was supported largely by internal CAMH funds and also in part by an Interdisciplinary Health Research Team (IHRT) grant theCanadian Institutes ofHealth Research (CIHR). Final analysiswas conducted with support from the Pharmacoeconomic Research Unit at the University of British Columbia.

Notes

^† NS = Not significant.

∗ “Prescription opioids” refers to all opioid products other than heroin, including non-prescription codeine (e.g., Tylenol #1®), regardless of whether it was for medical use (by prescription) or non-medical use.