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.