Increasing tramadol utilisation under strict regulatory control of opioid prescribing – A cross-sectional study in Taiwan from 2002 through 2016

Background/Purpose Prescribing of opioids to patients with non-cancer pain is strictly regulated in Taiwan, but tramadol is not included in the regulation on chronic opioid prescribing. This study aims to identify the utilization trend of prescribing tramadol and other opioid analgesics and investigate the influence of government regulation on opioid prescribing in Taiwan. Methods This cross-sectional study used the Taiwan National Health Insurance claims database and the cancer registry from 2001 through 2016. The annual number of adult opioid users, opioid utilization (Defined Daily Doses [DDDs]/1000 registrants) and the number of supply days were enumerated for each calendar year and stratified by cancer or non-cancer patients. Descriptive statistics were used to report the trends in utilization for each calendar year. Results The regulation strictly limited persistent use of opioids for patients with non-cancer pain, of which only a small proportion of fentanyl (20%) and morphine (<2%) users were prescribed with an annual number of supply days greater than 28 days. The annual utilization of morphine (6.4–53.5 vs. 1.1 to 9.6 DDD/1000 registrants) and fentanyl (8.3–37.0 vs. 0.16 to 1.8 DDD/1000 registrants) to patients with cancer was consistently higher than patients without cancer. In contrast to morphine and fentanyl, the utilization of tramadol prescribed to patients without cancer increased 92.2-fold (3.7–341.2 DDD/1000 registrants) from 2002 to 2016. Conclusion The regulation in Taiwan limited the prescribing of selective opioids for patients with non-cancer pain and the substitution of tramadol for other opioids may have safety implications.