Rising dispensation of prescription opioids confirmed

Fischer, also the CIHR/PHAC applied public health chair, notes POs are essential medication for treating severe and chronic pain. But, in recent years, they have been associated with strongly increasing morbidity (i.e., misuse and treatment admissions) and mortality (i.e., overdose deaths) in Canada.

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 2,700 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.

Based on an analysis of defined daily doses (DDD) of weak and strong POs per 1,000 people set by the World Health Organization (WHO), Canada’s dispensation of the drugs increased by 13.1 per cent. The amount of all dispensed POs rose from 20.3 DDD/1,000 people in 2005 to 23.0 DDD/1,000 people in 2010.

While the volume of dispensed strong POs rose by 42.1 per cent (7.6 to 10.8 DDD/1,000 people), the volume of weak ones dropped slightly by 4.4 per cent (12.7 to 12.2 DDD/1,000 people).

Based on WHO standards, the researchers defined strong POs as hydrocodone, hydromorophone, oxycodone, fentanyl, meperidine, methadone and morphine. The WHO defines codeine and its combination products as weak POs.

The research team included SFU adjunct professor Wayne Jones from the Centre for Applied Research in Mental Health and Addiction (CARMHA) and University of Toronto researchers Murray Krahn and Juergen Rehm.

North America has the highest POs-dispensation rate in the world and previous studies indicate increased dispensation of the painkillers is linked to increased POs-related illnesses and deaths. Governments are developing policy measures on how to reduce POs-related harms to public health. They include improved prescription monitoring and guidelines for opioids.

Given harm-related issues and that little is known about why POs dispensation is increasing, the study has a warning.

“Canada currently finds itself at a major policy and practice development juncture in regard to opioid use that, on the one hand, ought to maximize availability of opioid-supported care for chronic and severe pain with optimal standards and outcomes, while minimizing rapidly rising opioid-related problems and harms...

“The quantity and quality of opioids dispensed — different as these are between Canadian provincial jurisdictions — undoubtedly constitute a crucial variable in this challenge, yet key data are currently missing to guide decision making on the basis of evidence. This issue urgently requires further targeted investigation.”

Provided by Simon Fraser University