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Lethal Opioid W-18 May Not Actually Be an Opioid, Study Shows

Recent years have seen the rise in popularity of several unexpected substances like bath salts, synthetic marijuana and W-18, which is the latest of these threats. These mysterious drugs often burst onto the scene accompanied by news reports and a sudden surge in overdose deaths seen in communities throughout the U.S and Canada. Just when the shroud of mystery surrounding a new drug seems to lift, a new substance takes it place to become the latest nationwide danger.

W-18 Initially Classified as a Powerful Opioid

First discovered during experimentation with analgesic painkillers in the 1980s, W-18 resurfaced as a designer street drug after almost three decades of obscurity. During initial testing, the drug was observed to be a hundred times more potent than fentanyl, which itself is an opioid painkiller that’s 50 times more potent than heroin and 10,000 times stronger and morphine.1 The drug was never picked up by pharmaceutical companies, but recent years have seen W-18 become available for purchase over the internet, distributed from overseas as well as from Canada where the drug was initially developed. Due to its accessibility, W-18 has achieved rapid popularity throughout North America and Europe as an extremely dangerous and potentially lethal street drug.

Early this year, there were a number of reports describing W-18 as the latest new drug in the ongoing opioid epidemic. Since the drug was developed during experiments with painkillers and its effects have been likened to those of opioids, W-18 was described as an opioid drug of unprecedented lethality.2 However, there was something about W-18 that was very different from opiate painkillers and other opioid substances. For instance, the drug isn’t detected in any of the standard drug screens, even those that are specifically used to screen for painkillers. Also, naloxone — used in emergency situations to reverse an opioid overdose — has no effect on W-18 overdose victims. Despite these inconsistencies, W-18 continued to be referred to as an opioid, particularly because of the spike in overdose deaths that were being attributed to W-18 use.

Overdose Deaths Skyrocket Due to W-18

Previously, there was a trend in which heroin dealers would dilute their supply of heroin with additives like baking soda in order to increase the amount of heroin they had to sell. But since this would weaken the strength of the heroin, they would add small amounts of fentanyl to increase the strength of the heavily adulterated combination. This resulted in a spike in overdose deaths due to the fentanyl-laced heroin that drug users were using, particularly along the American East Coast. Therefore, it was only a matter of time before W-18 — reported to produce a heroin-like intoxication while being many times more toxic than fentanyl — was used in a similar manner, causing more spikes in overdose deaths.3 In addition, W-18 tends to come in the form of white powder, causing it to sometimes be mistaken for heroin or the powdered form of fentanyl.

To understand just how lethal W-18 really is, consider the following. In the state of Maine alone, there were 272 overdose deaths caused by W-18 over the course of 2015. By comparison, the combined overdose deaths for heroin and fentanyl were 157 while pharmaceutical opioids were the cause of 111 overdose deaths.4 In short, there were 2.5 times more deaths caused by W-18 — still a relatively new substance that’s not yet as widely used as other opioid drugs — than overdose deaths caused by opioid painkillers in general. In more urban areas, this discrepancy is significantly greater, which is why W-18 has become such a prominent concern for law enforcement, public officials and citizens alike.

New Study Disproves Opioid Status of W-18

The drug may offer heroin-like effects, but a recent study has found that W-18 is actually not an opioid at all. Specifically, the authors of the study — scientists from the National Institute on Drug Abuse, the University of North Carolina at Chapel Hill, Memorial Sloan Kettering Cancer Center and the Scripps Research Institute — noted that in both human and animal trials, neither the drug nor any of its chemical metabolites had any effects on opioid receptors.5 For good measure, a substance called W-15, which is chemically adjacent and considered very similar to W-18, was put through the same tests. Both W-18 and W-15 were found to produce none of the opioid-like effects that have been attributed to these drugs. W-18 was even observed as being ineffective to psychoactive drug receptors.

According to the authors, the opioid classification and effects have been mistakenly attributed to W-18 due to the frequency with which law enforcement officials obtained the drug from substance users who were also using heroin and fentanyl. The drug has also been found mixed into batches of heroin and fentanyl, leading many to attribute the spike in deaths caused by those drugs to the presence of W-18. The individual responsible for the creation of W-18 has also admitted that the drug was tested very minimally with only anecdotal evidence to suggest opioid-like effects.6 The minimal testing consisted of brief comparisons of the drug wherein it was found quite similar to both analgesic and non-analgesic substances in non-specific categories. In fact, W-18 bears greater resemblance, at least on a molecular level, to certain antibiotics than it does to fentanyl or any other opioids.

If W-18 were, in fact, as powerful an opioid as was initially reported, even the smallest amount of the drug would likely be fatal. But such extreme lethality has not actually been observed. The observations that have been made, however, portray W-18 as posing very minimal risk unless taken as high doses. In particular, the drug has been observed to behave similarly to a serotonin antagonist and reuptake inhibitor, binding weakly to serotonin and benzodiazepine receptors and showing a very weak affinity for histamines. Therefore, it begins to make sense why W-18 wouldn’t be detected by traditional drug tests and wouldn’t be affected by naloxone.

Although its opioid status has been disproven, that doesn’t mean that W-18 is not a cause for concern. Additional studies are needed so that we can discover more about the potential dangers of using W-18 and the reactions it can cause when combined with opioids.



Written by Dane O’Leary