Codeine, oxycodone, and tramadol prescription prior to overdose deaths compared to toxicological findings

Background:

Codeine, oxycodone, and tramadol are the most commonly prescribed opioids in Norway. Furthermore, each of these opioids are detected in approximately 10% of overdose deaths during autopsies. To effectively implement preventive measures against overdose deaths, it is crucial to determine whether these opioids were obtained through legitimate prescriptions or not.

Methods:

The study utilized data from the Norwegian Cause of Death Registry (NCoDR), Norwegian Prescribed Drug Registry (NorPD), and forensic toxicological results obtained from forensic autopsies spanning the period from 2004 to 2021. The study specifically examined the prescription patterns of codeine/acetaminophen, oxycodone, and tramadol within twelve and two months preceding death in cases of overdose where codeine, oxycodone, and tramadol were detected during autopsy. More advanced statistical methods and time trend studies will be performed before the conference.

Results:

A total of 3,765 overdose deaths were analysed. Among these, 857 (23%) were attributed to oxycodone, codeine, or morphine, while 395 (10%) were caused by other synthetic opioids such as tramadol, buprenorphine, fentanyl, and others. Men accounted for 2,746 (73%) of the overdose deaths. Codeine was detected in 326 cases, oxycodone in 316 cases, and tramadol in 220 cases. Regarding the share of prescriptions prior to death, for overdose deaths with codeine detected in blood at autopsy, the percentages were 76% within the past 12 months and 67% within the past two months. For oxycodone, the corresponding percentages were 56% and 53%, respectively. In the case of tramadol, the percentages were 66% and 58%, respectively. Furthermore, the share of women with dispensed drugs was higher compared to men. Specifically, for the past two months before death, the percentages were 73% versus 61% for codeine, 65% versus 45% for oxycodone, and 63% versus 53% for tramadol. Age differences were observed, and the following numbers corresponding to age below/over 40 years were 50% vs. 70% for codeine, 34% vs. 63% for oxycodone, and 37% vs. 68% for tramadol. Concomitant findings of at least one illicit, psychoactive drug was also studied, and the share of prescriptions was lower among those who also used illicit drugs: 48% vs. 71% for codeine, 29% vs. 66% for oxycodone, and 49% vs. 63% for tramadol.     

Conclusions:

The study found that the share of overdose deaths with prior dispensation of codeine, oxycodone, or tramadol was highest for codeine, with approximately 70% of the cases. Additionally, more than half of the deaths with oxycodone and tramadol detected also had a prescription history. Prescription drug use was associated with higher age, the absence of concomitant illicit drug use, and being female. Conversely, the absence of prescription drug use was associated with being male, using illicit drugs, and being younger.