• Vol. 36 No. 9, 774–777
  • 15 September 2007

Concomitant Use of Midazolam and Buprenorphine and its Implications Among Drug Users in Singapore



Introduction: The aim of this study was to determine the prevalence and characteristics of benzodiazepine (BZD) abuse among intravenous opioid users in Singapore. Materials and Methods: Eligibility criteria for inclusion in this study were all intravenous buprenorphine abusers, who presented to the Community Addictions Management Programme (CAMP) over a 1-year period from February 2005 to January 2006. One hundred and twenty subjects, who consented to the study, completed an interviewer-administered questionnaire and underwent blood test for blood-borne viral infections. Results: The age of the 120 subjects ranged from 20 to 64 years, with a mean age of 39.0 (SD 8.0) years. The majority of the participants were male (90.0%); 48.3% were Chinese. Ninety-eight (81.7%) patients were using BZDs concomitantly. Midazolam was the most commonly used BZD. Buprenorphine abusers who were concomitantly using BZDs were significantly younger and reported an earlier age of onset of illicit drug abuse as compared to those not using BZDs. Those abusing BZDs were more likely to share syringes (x 2 =5.8, P = 0.02), and were more likely to be seropositive for hepatitis C virus (x 2 =4.3, P = 0.04). Conclusions: This study highlights the extreme caution that needs to be exercised in prescribing BZDs to all patients in general and patients with injecting drug use or histories of drug abuse in particular. At a public health level, general practitioners (GPs) who prescribe buprenorphine should have compulsory training which highlights the potential dangers of abuse and concomitant abuse of BZDs.

Benzodiazepines (BDZs) (commonly known as “sleeping pills”) are routinely and successfully used in the treatment of sleep and anxiety disorders. However, studies have indicated that BZD use among injecting drug users (IDUs) constitutes a major clinical and public health problem. Misuse has been linked to higher rates of risk-taking behaviour (such as needle sharing) psychopathology, reduced health and social functioning and a greater risk of opiate overdose.1 Studies conducted in the United States, Europe and Australia indicate that BZD use is extremely common among IDUs.2-4 Klee et al2 found the use of temazepam to be associated with more needle sharing in the preceding 6 months, while van den Hoek et al5 reported BZD use to be a predictor of hepatitis C seropositivity in a Dutch study of IDUs. Studies have also suggested a link between BZD use and human immunodeficiency virus (HIV) risk-taking among IDUs.6 BZD dependence is a global phenomenon in heroin-abusing populations and in patients undergoing methadone maintenance treatment (MMT), with lifetime prevalence reported as 61% to 94%.4,7 BZD use in MMT patients has been associated with higher risk-taking behaviour,8 a higher risk for infectious diseases,9 and an 8-fold likelihood of death when compared to patients on MMT who are not abusing BZDs.10

This article is available only as a PDF. Please click on “Download PDF” to view the full article.