Non-medical prescription opioid use (NMPOU) and related harms – e.g., morbidity and mortality – have become a major public health challenge in North America (i.e., the US and Canada). There, some 5% of the general population report NMPOU; these rates are substantially higher among vulnerable groups (e.g., high-school students; ). In recent years, prescription opioids (POs) have replaced heroin as the primary opioid among street drug users, which has vanished from street markets in many cities (). Treatment demand for PO dependence has substantively increased across North America (). In 2008, 14,800 PO-related accidental poisoning deaths occurred in the US, more than heroin- and cocaine-related deaths combined (). In Canada, PO-related death rates have also sharply risen, and are estimated to constitute up to 50% of annual drug deaths ().