This article is more than 5 years old. Information may no longer be current.

Tamper-resistant formulations of higher-strength oxycodone decrease use

Dispensing rates for higher-strength oxycodone formulations among Australians younger than 65 years decreased when tamper-resistant versions were implemented, according to findings recently published in the Canadian Medical Association Journal.

Commissioner Scott Gottlieb, MD, announced plans to reduce exposure to opioids by promoting the development of new versions of medications that are harder to manipulate and abuse. The move was largely lauded by several pain management experts who spoke to Healio Family Medicine about the FDA strategy.

In the new study, researchers noted that although Australia switched all controlled-release oxycodone to tamper-resistant formulations in April 2014, there are “no definitive studies” to show how this impacted oxycodone use.

Andrea L. Schaffer MBiostat PhD, of the Centre for Big Data Research in Health at the University of New South Wales and colleagues analyzed oxycodone dispensing, discontinuing and switching among approximately 2.5 million Australians from 2012 to 2016. Calls to a poison information center during the same time frame were also examined.

Researchers found that after the reformulation, dispensing decreased for 40 mg to 80 mg oxycodone controlled-release (total level shift –31.5%, 95% CI, –37.5 to –24.9) and 10 mg to 30 mg (total level shift –11.1%; 95% CI, –17.2 to –4.6) in participants younger than 65 years, but dispensing remained the same in patients older than 65 years. The decision to stop using strong opioids did not increase (adjusted HR = 0.95; 95% CI, 0.91- 1), but switching to oxycodone/naloxone did increase (adjusted HR = 1.54; 95% CI 1.32-1.79) when data from the previous year was analyzed.

In addition, researchers also found that shifting to morphine varied by the person’s age (P < 0.001), with the largest increase seen in participants younger than 45 years (adjusted HR = 4.33; 95% CI, 2.13-8.8). Those who shifted after the reformulation were more likely to receive a tablet strength of 40 mg or more (adjusted OR = 1.4; 95% CI, 1.09-1.79). There were no changes in calls for unintentional poisoning to the poison control center for injected oxycodone, but such calls for oral oxycodone increased immediately after the reformulation (incidence rate ratio = 1.31; 95% CI 1.05–1.64).

“The observed decline in dispensing of higher-strength oxycodone [controlled-release] in participants less than 65 years of age may be due to an increase in switching to other strong opioids, chiefly morphine, rather than an increase in ending use,” Schaffer and colleagues wrote. “This is of concern because it suggests that people may be seeking out opioids without tamper-resistant properties; however, as with all observational studies, we could not establish a causal relationship between the reformulation and the outcomes, and can report only associations.” – by Janel Miller

Disclosures: Schaffer reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.