The United States is facing an epidemic of opioid addiction. One response has been to restrict the legal supply of drugs, which has led to a reduction in prescriptions. However, the impact of such supply interventions on drug purchasing overall — especially through illicit channels — is uncertain.
In a new study by James Martin, from Swinburne University of Technology, and colleagues, the authors analysed the impact of a US legal ruling in 2014 — which reclassified and restricted legal access to the most commonly prescribed opioids — on the sales of prescription medicines in illegal cryptomarkets. These function similarly to legal online markets such as eBay, but on the darknet. The authors analysed data on the number of for-sale listings and estimated purchases of prescription opioids from 31 cryptomarkets over a three-year period that spanned the legal change. Listings and sales for prescription opioids in the US markets increased significantly, compared with other types of drugs and opioids in other countries, after the legal ruling in 2014. In July 2016, prescription opioids accounted or 13% of all illicit drugs purchased in the United States on the cryptomarkets, but a time series analysis suggests that without the legal change, this would have been only 6%. The largest increases in sales were seen in the most potent opioids.
While the authors acknowledge that their evidence is not definitively causal, it suggests that restricting the legal purchase of opioids pushes consumers towards illegal markets, which are a gateway for some to more powerful drugs, in an unregulated environment.