Patterns of opioid and cocaine co-use: a descriptive study in a Canadian sample of untreated opioid-dependent individuals.

This study examined prevalence and patterns of co-use of opioids and cocaine in regular users of illicit opioids (N = 729) recruited from 5 Canadian cities. Fifty-seven percent (n = 417) reported having used both opioids and cocaine in the month and week preceding the interview; of these, 73% (n = 304) were able to identify a typical pattern of daily co-use. In a typical day, injectors of opioids and cocaine (n = 119) and injectors of opioids who inhaled cocaine (n = 111) showed stable opioid use but variable cocaine use, which peaked at 21 hr. Overall, 30% of the individuals used both drugs exclusively in a sequential fashion, 35% reported taking opioids and cocaine within the same hour, and 35% reported taking them together at the same time or mixing them. These findings indicate that different individuals display different patterns of opioids and cocaine co-use. Copyright 2005 APA, all rights reserved.