An SFU study has found that starkly increasing prescription of strong opioids is driving up dispensation of the painkillers in Canada. World Health Organization (WHO) standards define strong opioids as hydrocodone, hy­dro­morophone, oxycodone, fentanyl, mep­eridine, methadone and morphine. Codeine and its combination products are defined as weak opioids.

The study, “Differences and over-time changes in levels of prescription opioid analgesic dispensing from retail pharmacies in Canada,” analyzes dispensing data for opioids-related prescriptions. It is based on a representative sample of 2700 retail pharmacies in 10 provinces between 2005 and 2010. The Pharmacoepidemiology and Drug Safety Journal published the study’s results online in its July 2011 issue. 

The study notes that although strong opioids are essential medication for treating severe and chronic pain, in recent years they have been associated with increasing morbidity and mortality in Canada. 

Based on an analysis of defined daily doses (DDD) of weak and strong opioids per 1000 people set by WHO, Canada’s dispensation of the drugs increased by 13.1%. The amount of all dispensed strong opioids rose from 20.3 DDD/1000 people in 2005 to 23.0 DDD/1000 people in 2010. 
While the volume of dispensed strong opioids rose by 42.1% (7.6 to 10.8 DDD/1000 people), the volume of weak ones dropped slightly by 4.4% (12.7 to 12.2 DDD/1000 people). 

The study can be viewed online at http://onlinelibrary.wiley.com/doi/10.1002/pds.2190/abstract [8].