The proportion of illicit pills laced with a dangerous opioid has continued to rise throughout the coronavirus pandemic, doubling between January 2018 and December 2021, according to a recently published study funded by the US National Institute on Drug Abuse.

Using data on drug seizures collected by agencies across a nation-wide program, a team of researchers led by New York University epidemiologist Joseph J. Palamar evaluated the state of the opioid black market in the past three years.

They found the number of seizures of powders containing fentanyl – a rapid-acting synthetic opioid – leapt from 424 in the first quarter of 2018 to more than 1,500 at the end of last year, backing up predictions of a surging death toll from opioid overdoses in coming years.

Nearly 30 percent of the fentanyl-laced powders were already in pill form as well, with those seizures growing from 68 to 635 over the same period.

"For the first time we can see this rapid rise in pills adulterated with fentanyl, which raises red flags for increasing risk of harm in a population that is possibly less experienced with opioids," says Palamar.

Similar to analgesics like codeine and heroin, fentanyl is a compound used to treat pain by acting on opioid receptors in the brain.

The fact it absorbs far more easily into fat allows it to deliver rapid relief to patients experiencing serious discomfort.

Yet it's also a drug that sits on a knife's edge when it comes to dosage, with the amount needed for a therapeutic effect teetering dangerously close to an overdose. Around 50 times more potent than heroin, just a couple of milligrams of the substance is all it takes for a person to be at risk of dying.

It's this very potency that has made fentanyl a tempting choice of additive for a variety of illicit drugs, including heroin, cocaine, methamphetamine, and benzodiazepines; adding it into the mix provides a quicker effect for very little powder.

Yet in an unregulated market, there's no clear way of knowing exactly what's gone into any one home-brewed batch, especially once it's pressed into pill form and passed through a chain of buyers and sellers.

"Pills are often taken or snorted by people who are more naïve to drug use, and who have lower tolerances. When a pill is contaminated with fentanyl, as is now often the case, poisoning can easily occur," says National Institute on Drug Abuse director, Nora D. Volkow.

That poisoning is already occurring at unprecedented rates. Centers for Disease Control and Prevention data estimates around 106,000 people died from drug overdoses between October 2020 and October 2021, a number represented largely by fentanyl and similar synthetic opioids.

It's hard to know exactly what to do in the face of such striking numbers. What's more, unlike the health risks posed by an airborne virus, drug-taking behaviors are heavily stigmatized, making it far harder to build public support and build trust over effective strategies.

"We absolutely need more harm reduction strategies, such as naloxone distribution and fentanyl test strips, as well as widespread education about the risk of pills that are not coming from a pharmacy," says Palamar.

Sadly, a significant number of individuals experimenting with illegal opioids found themselves abandoned by a medical system that itself experimented with a historically laissez faire approach to pain management.

Without proper management in using heavily addictive medications that have been aggressively marketed by pharmaceutical companies for decades, many have found themselves with an addiction to painkillers and no easy way to get help.

Keeping tabs on alternative sources of opioids and the risks they pose to community health is vital if those lives are to be kept safe from harm.

The High Intensity Drug Trafficking Areas (HIDTA) grant program Palamar and his team used for their data doesn't differentiate between similar fentanyl-like compounds, or provide information on its concentration.

But when you're gambling on the presence of mere milligrams of a deadly substance, the conclusion is the same.

"The immediate message here is that pills illegally obtained can contain fentanyl," says Palamar.

Whether it's a message that will save lives, time will tell.

This research was published in Drug and Alcohol Dependence.