Benzodiazepine usage during 19.5 years in methadone maintenance treatment patients and its relation to long-term outcome.

Abstract

Background: Benzodiazepines (BDZs) abuse was found to cause diverse harmful effects among MMT patients. The current study evaluates prevalence rates of BDZ usage during 19.5 years in MMT, and its relation to patients' long-term retention in treatment.

Methods: All 787 opiate addicts who were ever admitted to the Adelson MMT clinic in Tel Aviv between 1993 and 2012 were studied. Observed and random urine results for BDZs usage were taken a few times every month. Positive for BDZ was defined in each month if at least one of the urines tested positive. Long-term retention was studied using Kaplan Meier analyses.

Results: BDZ prevalence among the MMT patients (ranged from 26 patients in 1994, and 300 to 350 since 2009) was about 35-40% in the last few years, with a "peak" of 61% followed by low rate of 25.4%. Followed up for up to 19.5 years, those who were negative to BDZ upon admission to MMT stayed longer in treatment (mean 8.5y, 95% Confidence Interval [CI] 7.6-9.4) than those who were positive to BDZ when admitted (mean 6.9y, 95% CI 6.2-7.7) (Kaplan Meier analyses p=0.01).

Conclusion: BDZs abuse is highly prevalent among MMT patients. Abuse of BDZ on entry to treatment predicts worse MMT outcome. High and low rates of BDZ abuse may also be attributed to staff tolerance of this abuse; thus, we strongly recommend a strict attitude by staff in order to reduce patients' harm.