Kratom: a ‘herbal drug’ with the potental to do more harm than good

Rapidly rising in popularity, kratom is hailed by some as a readily available pain remedy that is safer than traditional opioids, an effective addiction withdrawal aid and a pleasurable recreational tonic. But kratom also is assailed as a dangerous and unregulated drug that can be purchased on the Internet, a habit-forming substance that authorities say can result in opioid-like abuse and death.

Last week, the Food and Drug Administration announced that the herbal supplement kratom possesses the properties of an opioid, thus escalating the government’s effort to slow usage of this alternative pain reliever. The FDA states that the number of deaths associated with kratom use has increased to a total of 44, up from a total of 36 since the FDA’s November 2017 report. In the majority of deaths that FDA attributes to kratom, subjects ingested multiple substances with known risks, including alcohol. The presence of multiple drugs makes it difficult to determine the role any one of them played.

So, what is kratom, and why might it be dangerous?

A recent review explains that the leaves of Mitragyna speciosa (commonly known as kratom), a tree endogenous to parts of Southeast Asia, have been used traditionally for their stimulant, mood-elevating, and analgesic effects. The plant’s active constituents, mitragynine and 7-hydroxymitragynine, have been shown to modulate opioid receptors, acting as partial agonists at mu-opioid receptors and competitive antagonists at kappa- and delta-opioid receptors. Both alkaloids are G protein-biased agonists of the mu-opioid receptor and therefore, may induce less respiratory depression than classical opioid agonists. The Mitragyna alkaloids also appear to exert diverse activities at other brain receptors (including adrenergic, serotonergic, and dopaminergic receptors), which may explain the complex pharmacological profile of raw kratom extracts. Kratom exposure alone has not been causally associated with human fatalities to date. However, further research is needed to clarify the complex mechanism of action of the Mitragyna alkaloids and unlock their full therapeutic potential.

Another review adds that, by the early 2000s, kratom was increasingly used in the US as a natural remedy to improve mood and quality of life and as substitutes for prescription and illicit opioids for managing pain and opioid withdrawal by people seeking abstinence from opioids. There has been no documented threat to public health that would appear to warrant emergency scheduling of the products and placement in Schedule I of the CSA carries risks of creating serious public health problems. Banning kratom, risks creating public health problems that do not presently exist.

A third review explains that there are no published human pharmacologic, pharmacokinetic, or drug interaction studies on kratom or mitragynine, making it virtually impossible to fully understand kratom‘s therapeutic potential and risks and the populations most likely to benefit or experience harm from its use. Kratom has been used to ameliorate opioid withdrawal symptoms but also induces withdrawal. Human pharmacologic, pharmacokinetic and clinical data are of low quality precluding any firm conclusions regarding safety and efficacy. Kratom does cause a host of adverse effects without clear guidance for how they should be treated. There are numerous assessments where people have been unable to stop using kratom therapy and withdrawal signs and symptoms are problematic. Kratom does not appear in normal drug screens and, when taken with other substances of abuse, may not be recognized.

A systematic review evaluated all studies on kratom use and mental health published between January 1960 and July 2017. Its findings indicate kratom‘s potential as a harm reduction tool, most notably as a substitute for opioids among people who are addicted. Kratom also enhances mood and relieves anxiety among many users. For many, kratom‘s negative mental health effects – primarily withdrawal symptoms – appear to be mild relative to those of opioids. For some users, however, withdrawal is highly uncomfortable and maintaining abstinence becomes difficult.

In Europe, as of 2011, kratom has become a controlled drug in Denmark, Latvia, Lithuania, Poland, Romania and Sweden. In the UK, since 2016, the sale, import, and export of kratom are prohibited.

On balance, my conclusion is that we urgently need more data and meanwhile should avoid this ‘herbal drug’.