Trends in high-dose opioid prescribing in Canada.

OBJECTIVE: To describe trends in rates of prescribing of high-dose opioid formulations and variations in opioid product selection across Canada.

DESIGN: Population-based, cross-sectional study.

SETTING: Canada.

PARTICIPANTS: Retail pharmacies dispensing opioids between January 1, 2006, and December 31, 2011.

MAIN OUTCOME MEASURES: Opioid dispensing rates, reported as the number of units dispensed per 1000 population, stratified by province and opioid type.

RESULTS: The rate of dispensing high-dose opioid formulations increased 23.0%, from 781 units per 1000 population in 2006 to 961 units per 1000 population in 2011. Although these rates remained relatively stable in Alberta (6.3% increase) and British Columbia (8.4% increase), rates in Newfoundland and Labrador (84.7% increase) and Saskatchewan (54.0% increase) rose substantially. Ontario exhibited the highest annual rate of high-dose oxycodone and fentanyl dispensing (756 tablets and 112 patches per 1000 population, respectively), while Alberta's rate of high-dose morphine dispensing was the highest in Canada (347 units per 1000 population). Two of the highest rates of high-dose hydromorphone dispensing were found in Saskatchewan and Nova Scotia (258 and 369 units per 1000 population, respectively). Conversely, Quebec had the lowest rate of high-dose oxycodone and morphine dispensing (98 and 53 units per 1000 population, respectively).

CONCLUSION: We found marked interprovincial variation in the dispensing of high-dose opioid formulations in Canada, emphasizing the need to understand the reasons for these differences, and to consider developing a national strategy to address opioid prescribing.