Both natural and synthetic opioid drugs have been used as a popular therapy for chronic pain throughout history. However, their role as effective analgesics has been tainted by the potential for addiction, increased physical dependence, and often progressive reduction in drug efficacy. Currently, Canada is home to a raging opioid crisis with epidemic proportions of overdoses and related deaths as a result of prescription opioids (POs), as well as illegal and more potent synthetic opioids. In 2016, there were over 2500 opioid related deaths across Canada, and more than 3000 deaths are expected by the end of 2017. The rise in morbidity and mortality stemming from PO misuse has led Health Canada to declare this issue a major public health crisis.
One of the most commonly used opioids, oxycodone, was patented and marketed in 1992 as OxyContin. As the cause of almost 50% of opioid-related poisoning deaths, OxyContin was delisted from most Canadian provinces’ public drug formularies in 2012. This attempt to delegitimize OxyContin only gave way to increased use of other POs, particularly fentanyl. This represents a much greater concern because fentanyl is an extremely potent synthetic opioid, approximately 50-100 times stronger than morphine. Alarmingly, Canadian fentanyl consumption rates are among the highest worldwide, and the number of deaths involving prescribed or illegal fentanyl between January and March 2017 was double that of the same period in 2016.
This epidemic arises partly from Canada’s long history of over-prescribing practices. Dhalla, Gomes and Juurlink demonstrated that the top 20% of family physicians who prescribe opioids did so 55 times more often than the lowest 20%. Overprescribing practices may be positively associated with opioid-related mortality. Many studies have consistently suggested a correlation between PO availability and related morbidity and mortality in Canada. In particular, one study examining opioidrelated deaths between 2005 and 2011 reported significant correlations between PO dispensing and mortality due to oxycodone and fentanyl.
Overprescription is further compounded by the fact that opioids have been marketed without an upper dose threshold, despite limited evidence of their safety or effectiveness at high doses. In fact, increases in dosage for long-term treatment plans may lead to the development of tolerance over time, presenting an overarching concern for many individuals dependent on opioid therapy for chronic pain. Furthermore, a growing body of literature highlights the danger posed by morphine equivalent doses exceeding 200mg/day. The health repercussions are especially worrying for Ontario, given that this province has exhibited the highest annual rate of high-dose oxycodone and fentanyl dispensing between 2006 and 2011.
A report recently released by the Canadian Institute for Health Information warns that the opioid crisis presents a significant burden on the healthcare system due to the rising number of Canadians seeking emergency care for overdoses. As high PO availability and demand continue unabated in Canada, evidence-based population interventions are needed to understand and address the primary determinants and consequences of PO misuse. Given that opioid dispensing rates in Canada are much higher than those in other high-income countries, there is room for substantive reductions in PO prescription and improvements in physician and patient education. Unless measures are taken to address this crisis, the widespread availability of dangerous opioids, including fentanyl, will continue to pose a significant public health concern.
Written By Takhliq Amir
References may be found in journal.