Poison Control Calls for Kratom Rose Sharply, but the Caveats Are Crucial

"Just because it’s natural doesn’t mean it’s safe."

The plant-based drug kratom has dominated local news headlines over the past few years with both its benefits and its costs. As its role in society grows, the lack of evidence-based information about kratom’s safety is becoming increasingly clear. In an effort to fill in that gap, Ohio researchers investigated the number of kratom-related calls to poison control centers in the United States. The study, published Thursday, turned up some surprising results.

In the paper, published in Clinical Toxicology, the researchers from Nationwide Children’s Hospital in Columbus and The Ohio State University report that the number of kratom-related calls to poison control centers rose sharply over a seven-year period. Data from the National Poison Data System showed that 1,807 calls to poison control centers between 2011 and 2017 involved kratom.

In 2011, the number of calls involving kratom was only 13, and in 2017 it was 682 — a 52.5 percent increase. Of the 1,807 calls, 35 percent of cases involved an additional substance besides kratom, 88.9 percent involved adults 20 years or older, and 7.6 percent occurred in adolescents. Furthermore, the symptoms described in these kratom-related calls — seizures, confusion, agitation, and elevated heart rates — particularly stuck out to the authors.

However, while the data indicate a growing public health burden, C. Michael White, Pharm.D., a professor of pharmacy practice at the University of Connecticut who studies kratom and was not involved with the study, says it’s crucial to understand what we can — and cannot — interpret from this data.

Green Kratom Leaf
Kratom comes from an evergreen tree that grows in southeast Asia. 

Understanding the Results

In the paper, Dr. Henry Spiller, the director of the Central Ohio Poison Center at Nationwide Children’s Hospital, and his colleagues note that 65 percent of the exposures documented in the study occurred between 2016 and 2017. We cannot, however, assume this means that kratom use is simply increasing.

There are no reliable figures on how many people in the US are taking kratom, and without knowing that number, it’s hard to draw any conclusions about whether the number of adverse cases reflect dangerous products, risky use, or simply more people who are taking the drug.

White says the data offer valuable insights. They show, for example, that kratom use seems to be increasing in adults and teens and that the drug carries some health risks on its own — not just when combined with other drugs.

There are, however, crucial limitations to what we can gather from these numbers, he reiterates.

“Unfortunately, without reliable data on utilization (the demoninator in the equation when determining the rate of adverse events), it is difficult to know what these adverse event trends mean,” he tells Inverse. “Were there 1,807 adverse events per 1 million product purchases, per 10 million product purchases, or something else?” In other words, even though there’s a rise in the total number of people experiencing negative effects from kratom, these numbers don’t offer any insight into whether kratom has become riskier.

“There are four possible explanations for the phenomenon of increasing adverse events over time, and they do not have to be mutually exclusive,” White adds. “First, kratom might be becoming more dangerous over time. Second, kratom utilization is increasing over time, increasing the number of events seen. Third, people are more aware of kratom so poison control workers, first responders, family members, and emergency room personnel are asking and testing for it. Fourth, some people are beginning to use higher and higher doses of kratom changing its risk profile.”

Unfortunately, the new study doesn’t show which of these four explanations are correct. Additionally, White notes, the increased public awareness of kratom could lead to it being “an innocent bystander caught up in some adverse events it did not cause.”

Spiller acknowledges that the study can’t explain the increase — but there clearly is an increase.

An Atypical Opioid

Tramadol, opioid
The data suggest that kratom may be more similar to the atypical opioid tramadol than to other opioids like morphine or fentanyl.

A big part of the controversy about kratom’s safety is the drug’s potential similarity to opioid drugs, which are responsible for the country’s devastating opioid overdose crisis. The FDA, for one, has characterized the drug as a dangerous opioid, and previous research has suggested that kratom does indeed have opioid properties.

But other scientists have shown that its unique chemistry makes it more similar to the atypical opioid tramadol than conventional opioids like fentanyl or morphine. Spiller makes the same comparison.

“None of these are effects you’d expect from an opiate-like effect,” Spiller tells Inverse. “That’s a key feature. There’s almost a dual action with these alkaloids.”

In short, there remain a ton of unanswered questions about the risks and benefits of kratom — too many to allow us to draw definitive conclusions about the drug from Spiller’s data. Nevertheless, the fact that it’s a relatively unregulated grey-market herbal supplement that’s very easy to buy online has doctors like him worried. To understand whether kratom’s benefits outweigh its risks, more studies like this one need to be completed.

The website for a kratom vendor.
The website for a kratom vendor. The drug is easy to buy online.

Good Data Are Hard to Find

Kratom Pills

The lack of scientific context around kratom has characterized the public health debate for years, making kratom use statistics highly contentious. In 2018, for instance, the FDA released a set of case reports showing evidence of 44 deaths attributable to kratom since 2009, but critics quickly pointed out that almost all of those cases involved other deadly drugs. The new study shows a similar effect: among the 11 deaths counted among the 1,807 cases, all but two involved other drugs, including alcohol, fentanyl, and cocaine.

While the study sheds some much-needed light on the public health burden of kratom, it raises more questions than it answers. For now, White says there are some ways people can stay safe.

“I personally look at this data and caution people that kratom is not risk free,” he says. “If you want to use kratom, please only use products that are certified by an outside lab to be free of contamination and adulteration. Use the lowest dose you can for the shortest amount of time to get the job done.” He also says people shouldn’t drive under the influence of kratom or take it with other drugs.

Spiller sums up the situation simply: “Just because it’s natural doesn’t mean it’s safe.”

Media via Wikimedia / ThorPorre, Wikimedia Commons, Sacred Kratom, Wikimedia / Psychonaught, Flickr