Canada Admits That It Knows Very Little About W-18, the Drug It Just Banned

Facing public criticism for its decision to classify the potent drug called W-18 a "synthetic opioid", Canada's federal health department acknowledged on Monday that its critics may have a point.

The announcement comes in the midst of a public health crisis around fentanyl in Canada, with hundreds of reported overdoses throughout the country in the last few years. The government has claimed W-18 may be 100 times worse than fentanyl, and classified W-18 as a synthetic opioid — like oxycodone — because it may "have a significant negative impact on some of the most vulnerable people in our society," according to Health Minister Jane Philpott.

But Health Canada's recent statement notes that doubts about the June 1 classification of the drug as a synthetic opioid "have been raised recently by a number of credible sources." The primary concern noted in the statement is that "while the only publicly available scientific report compares W-18 and related compounds to opioids, it does not determine whether or not W-18 binds to opioid receptors in the body."

The scientific report the government references was conducted in 1984, and tested W-18 on mice. It has never been tested on humans, and while the Canadian government has said it may be 100 times stronger than fentanyl, it has never been compared directly to the substance in a study.

As such, Health Canada's classification of W-18 sparked heavy criticism from several experts. A pharmacology professor at the University of North Carolina who is conducting a study on W-18, Bryan Roth, told the Calgary Herald that: "As far as I have been able to determine there's no scientific data on the compound, other than this single patent. And in the patent, it's really impossible to determine much about the compound." He noted that experts currently don't know if W-18 is a dangerous drug.

Doctor Hakique Virani told VICE News that: "What we can say is that W-18 may well not be an opioid and that the assumptions that lead to the conclusion that it's an extremely powerful opioid were leaps at best, and clearly there's more work to be done to characterize how this molecule works in human beings."

Despite acknowledging these criticism, Health Canada's statement maintains that the government will move forward in its plans to criminalize possession, production, and sale of W-18, claiming "the decision was taken after careful consideration of several factors." One of the concerns cited is that users "may be tempted to experiment with W-18, mistakenly believing that it is safer than substances controlled under the [Controlled Drugs and Substances Act.]"

Recent reports have noted that the drug is beginning to surface in drug raids throughout the country, including in B.C. and Alberta. In May, Calgary police confirmed that a 35-year-old man died due to a drug overdose involving W-18, the first in the province.

Follow Davide Mastracci on Twitter: @davidemastracci