Regulatory and other responses to the pharmaceutical opioid problem

In reply: In response to our recent perspective article, in which we discuss Australian responses to the pharmaceutical opioid problem,1 Polasek and colleagues enquire why we do not refer to the potential of pharmacogenomics in identifying patients at increased risk of opioid toxicity. We agree that precision pain medicine based on genomic profile is an interesting approach, but it was not discussed for several reasons.

Firstly, we set out to detail current responses that have been implemented in Australia and other responses that could be broadened to have a greater immediate impact on opioid‐related harms.

Secondly, although pharmacogenomics may have a role in opioid prescribing in the future, evidence for this approach is still very much in its infancy. There is a lack of high quality cost‐effectiveness trials and genome‐wide association studies.2 There are also practical barriers to its widespread implementation and uptake in the treatment of pain. Delays in receiving test results need to be considered, especially (though not only) in cases of acute pain. Pharmacogenomic testing is currently not subsidised by Medicare, meaning the patient would be burdened with the cost.3 There is also a lack of testing infrastructure. It is important to acknowledge as well that most patients with pain have a low risk of developing an opioid use disorder4 and may consider pharmacogenomic testing an invasion of privacy. To date, most of the work in this area has focused on understanding the polymorphisms affecting codeine metabolism specifically. The recent rescheduling of codeine in Australia has reduced its availability in the community5 and is likely to have had reduced risky patterns of use. Australia currently uses a wide range of synthetic and semisynthetic opioids, for which there are limited or no pharmacogenomic studies.

Finally, pharmacogenomics may provide useful clinical information on opioid metabolism or receptor subtype, but opioid‐related harms (eg, overdose and opioid use disorders) have complex psychosocial determinants. To address the pharmaceutical opioid problem now, we need to focus on evidenced‐based public health approaches that are feasible and scalable.