Large North American cities have been plagued with a spectacular increase in opioid-related overdoses over the last few years. Some Canadian provinces were more affected than others by this phenomenon. Studies conducted in Western Canada have shown the widespread presence of fentanyl and its analogues in street drugs [1Tupper K.W., et al. Initial results of a drug checking pilot program to detect fentanyl adulteration in a Canadian Setting Drug Alcohol Depend 2018 ;  190 : 242-245 [cross-ref]

Cliquez ici pour aller à la section Références], little is known about the pattern of drug use and the contaminants commonly found in illicit drugs throughout Quebec.

In August and September 2017, 175 individual reporting having used illicit drugs in the past three days were recruited in nine community and public organizations offering harm reduction services in Montreal. Participants filled a questionnaire to describe their drug use over the previous three days and provided a urine specimen. Samples were analyzed by UPLC-MS/MS using a sensitive targeted MRM workflow for the identification of traditional and emerging compounds on a Waters UPLC-Xevo-TQS micro-system (Milford, MA, USA).

Among the 175 participants, 65% were male, 35% were aged 25–34 years, 16% reported an opioid overdose in the previous month and 60% reported self-injecting illicit drug over the last 3 days. Cocaine and its metabolites were detected in the urine of 90% of participants, while 59% of samples contained Levamisole. Heroin was detected in 39% of the samples. Fentanyl was detected in 20% of submitted samples, while only 4% of participants reported its use. The proportion of samples containing fentanyl was higher among participants reporting heroin use than among those who didn’t (39% vs. 7%; P<0.0001). Methamphetamine was detected in 42% of samples and hydromorphone in 18%. Acetyl-fentanyl was detected in three samples and U-47700 in one sample; these four samples also contained fentanyl.

This study showed that an elevated proportion of cocaine and crack users in Montreal are contaminated with levamisole. It also showed that 20% of participants had recently used fentanyl, most unknowingly while using heroin.

Given the high potency of fentanyl and its analogs, harm reduction measures such as naloxone distribution are needed to prevent overdoses.