Heroin transition risk among daily and non-daily cannabis users who are non-injectors of heroin.

AIMS: Non-injecting heroin use (NIU) has been identified as a potential precursor for the transition to injecting drug use (IDU). This paper examines and compares heroin transition risks between two groups of Mexican American cannabis users (daily (DU) vs. non-daily (NDU)) who are NIUs.
METHODS: Data for this analysis are from structured interviews with 300 street-based recruited male and female NIUs in San Antonio, Texas using an adaptive sampling methodology. Three variables (being a former injector, daily heroin use, and being dependent on heroin) were used to create a summative scale measuring heroin transition risk and dichotomized into "no attributes" and "1-3 attributes".
RESULTS: Initial univariate logistic regression analysis indicated an association between heroin transition risk and the cannabis user groups with three fourths of the NDU having transition risk attributes. In the multivariate model, three factors were found to be independently associated with heroin transition risk. Heroin transition risk was positively associated with having used heroin for a longer period of time. An inverse relationship was found with DU of cannabis and those reporting alcohol use in the past month being less likely to be associated with heroin transition risks.
CONCLUSIONS: Findings tentatively indicate that DU of cannabis may be interpreted as a form of self-regulation and potentially deterring problematic heroin use among Mexican American NIUs and possibly other polydrug users in similar social environments. However, the authors discuss alternative interpretations of these findings. Nevertheless, findings may be used to inform specific policies and intervention strategies to prevent transitions to injecting and other harmful health consequences among NIUs.