Kratom - Don't Believe the Hype

The CDC came out with a brief 2 page report on kratom deaths 3 days ago (1). That was all it took for the Twitterati to proclaim that there were many more deaths from alcohol and I suppose there was a post about even more deaths from cigarette smoking but thankfully I missed that one. When I pointed out that it was clearly an addictive drug and lifelong disability (a very significant problem) may be the issue - the defenders of kratom stepped up and talked about how harmless it is and also how it is advantageous for people who cannot afford medication assisted treatment (MAT) (buprenorphine preparations, methadone, or naltrexone extended release injections) for opioid use disorder (OUD). The expected personal attacks and sarcasm followed.

Kratom is an interesting compound because like many psychoactive botanicals there is a history (2). Kratom itself is basically leaf material from the kratom tree (Mitragyna speciosa). The leaves can be smoked or chewed. They can also be dried and powdered. The powdered form is what is typically available for sale. The powder can be packaged in capsules and taken orally, brewed into a tea, or rendered into a syrup and formed into pills. Fresh leaves can be chewed with or without betel nuts. Kratom has been used in Malaysia since the 19th century to “heal opium addiction”. A recent paper referenced a study of kratom users that were using an estimated 4-8 g/day (8). Converting based on typical leaf content means that these users would be exposed to a maximum of 120-180 mg mitragynine and 1.1 - 3.4 mg 7-hydroxymitragynine.   Rӓtsch suggests in his text that “in studies with mice, even extreme dosages of 920 mg/kg did not produce any toxic effects”. He describes “self experiments” in the literature suggesting that kratom can be both stimulating like cocaine and sedating like opium. The only comment on addiction is “The alleged kratom addiction is a Thai cultural phenomenon” (p. 367).  Like most intoxicants in the modern era there is progression to intravenous use.  Although that is currently rare, there are case reports of intravenous use of kratom extracts.

The CDC document describes a series of deaths in 11 states between July 2016 and June 2017 and an additional 27 states from July to December 2017. The data set was from the SUDORS (State Unintentional Drug Overdose Reporting System) and consisted of 27,338 overdose deaths, 152 (0.56%) of which were kratom positive. There is no standard postmortem toxicology protocol and as previously noted that is problematic in determining the drugs present in these analyses. As shown by the table from this report in 91 cases kratom was considered the cause of death, but numerous other substances were present. In seven cases kratom was the only substance noted in postmortem toxicology, but additional substances cannot be ruled out.

A report in the New England Journal of Medicine, looked at 15 cases of death (4) associated with kratom in Colorado. In this series the authors used more rigorous toxicological analysis with high-performance liquid chromatography – mass spectrometry. Whole blood mitragynine concentrations were noted between 16-117 ng/ml and up to 4800 ng/ml. In this series, 14 of 15 deaths had multiple drugs leading the authors to conclude that these deaths were kratom related.  This series of cases illustrates the importance of toxicological analysis and specifically plasma levels of the drug to correlate with various toxidromes and post mortem toxicology.

The leaves of Mitragyna speciosa, contain multiple alkaloids including mitragynine, 7-hydroxymitragynine, paynantheine, speciocilatine, and speciogynine. The crude alkaloid extract consists primarily of 66% mitragynine and 2% 7-hydroxymitragynine. The extraction process may be protective against toxicity for many people that brew the leaves into a tea, chew the leaves, or ingest the powdered leaves as capsules but even then the concentration of these alkaloids may vary from species to species. Counting on an inefficient extraction process for safety is probably not the best idea.  The other property of the raw material is that the alkaloids are mixtures of  opioid receptor agonists and antagonists that may determine the net effect. Searching the way these products are sold there is really not much about concentration of any associated alkaloids other than mitragynine.  The plant itself contains more than 40 unique alkaloids (8).

Until recently, the pharmacology of mitragynine and 7-hydroxymitragynine were unknown. There is research to suggest (5) that opioid receptors mediated the primary effects. Both compounds had binding affinity for the mu opioid receptor (MOR). They were also active in tissue essays and blocked by naloxone.  Some of these effects were inconsistent between laboratory species. Activity was reported at a number of non-opioid receptors as well. The pharmacology of mitragynine and 7-hydroxymitragynine is now well-characterized. Recent studies show that mitragynine is a partial agonist at the human mu opioid receptor (hMOR), and a competitive antagonist at the human kappa opioid receptor (hKOR), and an antagonist at the human delta opioid receptor (hMOR) but with very low potency. The authors studied these compounds against all three human opioid receptors looking at both functional activity (EC50 and IC50) and binding affinities (Ki) and discovered they were consistent across those experiments. They concluded that mitragynine (0.233 μM) And 7-hydroxymitragynine (0.047 μM) had significant binding affinity for hMOR. The remainder of the paper focuses on medicinal chemistry theory, specifically how opioid -like compounds that bias intracellular signaling toward G proteins rather than β-arrestin may be better candidates for opioid analgesics with low addiction potential and better side effect profiles and possibly antidepressant activity. They synthesize a number of analogues and look at their agonist activity at hMOR. The authors conclude that the psychoactive activity of Mitragyna is most likely due to their action at hMOR. They also point out that due to the competitive nature of the alkaloids the gross effects will be due to that balance of agonism and antagonism.

The alkaloid and methanol crude extracts of kratom are both inhibitors of CYP3A4 and CYP2D6 in vitro. No specific components have been identified with this activity and there has been in vivo confirmation (8).

Another paper (6) looks at the “unanticipated toxicity” of kratom. This group looked at the LD50 of mitragynine, 7-hydroxymitragynine, and heroin. The LD50 is a measure of acute toxicity and what single dose will kill half of the research animals. In this case mice were used and the researchers were surprised to find that an intravenous dose of either mitragynine or 7-hydroxymitragynine were as lethal as heroin. No lethal doses were observed for oral dosing in a range of 6.25-50 mg/kg. the lethal intravenous dose was midpoint in that range. Researchers observed that the mice appeared to die from respiratory depression within 10 minutes of direct exposure. In the surviving mice many were noted to have seizures in the first 20 minutes.  In a separate review, the authors point out that with a typical 8 g dose of kratom powder, the levels of 7-hydroxymitragynine, may be too low to cause a pharmacologically relevant effect at the opioid receptor. 

The research on kratom has elucidated receptor activity in opioid receptors. The activity is complex but the mu opioid receptor is clearly involved and is the likely site of the psychoactive effects and the application of opioid substitution in people with addictions. The receptor effect is complicated and likely involves more than the mu opioid receptor. The research also suggests that activity at murine and human opioid receptors are not equivalent. Persons acquiring kratom in the powder form need to consider that the ratio of mitragynine to 7-hydroxymitragynine likely varies with species and source. The 7-hydroxymitragynine is 52 times as potent as mitragynine at the MOR and 13 times as potent as morphine. Products made from extractions will be more potent.

All of this information should create skepticism in prospective kratom users. As addiction psychiatrist I can attest to the fact that it is addicting and with any addiction there is a tendency to escalate the dose. Many people with addictions as noted in the above table are using multiple substances some of which are also agonists at the opioid receptor. If you are considering kratom as a treatment for opioid addiction or chronic pain there are much, much safer and effective ways to proceed.


George Dawson, MD, DFAPA



References:


1. Olsen EO, O’Donnell J, Mattson CL, Schier JG, Wilson N. Notes from the Field: Unintentional Drug Overdose Deaths with Kratom Detected — 27 States, July 2016–December 2017. MMWR Morb Mortal Wkly Rep 2019;68:326–327. DOI: http://dx.doi.org/10.15585/mmwr.mm6814a2External

2: Rӓtsch C. The Encyclopedia of Psychoactive Plants: Ethnopharmacology and Its Applications. Park Street Press. Rochester, Vermont, 2005. pages 366-367.

3: Olsen EO, O’Donnell J, Mattson CL, Schier JG, Wilson N. Notes from the Field: Unintentional Drug Overdose Deaths with Kratom Detected — 27 States, July 2016–December 2017. MMWR Morb Mortal Wkly Rep 2019;68:326–327. DOI: http://dx.doi.org/10.15585/mmwr.mm6814a2

4: Gershman K, Timm K, Frank M, Lampi L, Melamed J, Gerona R, Monte AA. Deaths in Colorado Attributed to Kratom. N Engl J Med. 2019 Jan 3;380(1):97-98. doi: 10.1056/NEJMc1811055. PubMed PMID: 30601742.

5: Kruegel AC, Gassaway MM, Kapoor A, Váradi A, Majumdar S, Filizola M, Javitch JA, Sames D. Synthetic and Receptor Signaling Explorations of the Mitragyna Alkaloids: Mitragynine as an Atypical Molecular Framework for Opioid Receptor Modulators. J Am Chem Soc. 2016 Jun 1;138(21):6754-64. doi: 10.1021/jacs.6b00360. Epub 2016 May 18. PubMed PMID: 27192616; PubMed Central PMCID: PMC5189718.

6: Smith LC, Lin L, Hwang CS, Zhou B, Kubitz DM, Wang H, Janda KD. Lateral Flow Assessment and Unanticipated Toxicity of Kratom. Chem Res Toxicol. 2018 Nov 16. doi: 10.1021/acs.chemrestox.8b00218. [Epub ahead of print] PubMed PMID: 30380840.

8: Kruegel AC, Grundmann O. The medicinal chemistry and neuropharmacology of kratom: A preliminary discussion of a promising medicinal plant and analysis of its potential for abuse. Neuropharmacology. 2018 May 15;134(Pt A):108-120. doi: 10.1016/j.neuropharm.2017.08.026. Epub 2017 Aug 19. Review. PubMed PMID: 28830758.

9: Post S, Spiller HA, Chounthirath T, Smith GA. Kratom exposures reported toUnited States poison control centers: 2011-2017. Clin Toxicol (Phila). 2019 Feb 20:1-8. doi: 10.1080/15563650.2019.1569236. [Epub ahead of print] PubMed PMID:30786220.

Supplementary:

FDA Guidance On Lead and Nickel Exposure from kratom products:  Link

"Based on these test results, the typical long-term kratom user could potentially develop heavy metal poisoning, which could include nervous system or kidney damage, anemia, high blood pressure, and/or increased risk of certain cancers."

Graphics Credit:

1.  Mitragynine and 7-hydroxymitragynine were done with ChemDoodle.

2.  Table is from the CDC per reference 3 and public domain.

Better Living Through Pharmacology

One of the great unspoken biases in psychopharmacology is the belief system about the medication.  What is the medication supposed to do after all?  Is it supposed to be life-changing in terms of positive improvements?  Is it supposed to eradicate all types of depression and anxiety?  Is it supposed to create the perfect cognitive and emotional state?  Is it supposed to turn an average student into an MIT professor?  Is it just supposed to treat a symptom and if so - how many symptoms?  Does it need to address some underlying physiological disturbance or can anyone take it and get the same benefits?  These are all unspoken biases about psychiatric medications that need to be explored with people who are taking the medications.  I don't think that a psychiatrist should even take for granted that a patient knows the difference between depression or anxiety or why thinking that Attention Deficit Hyperactivity Disorder (ADHD)  with essentially no impairment in professional, academic, or social life is not the same as having that diagnosis.

One of the best examples is the myth of the perfect mind.  If ADHD is finally diagnosed and treated, that means the person's mental functioning will either be normalized or be much better than it was in the past.  It should be possible to read entire book chapters and even books for the first time.  That is true isn't it?  It turns out that the effects of most medications for ADHD are modest and rarely life changing.  I have talked with many people who had clear diagnoses of ADHD as children who did not like the side effects of the medication and stopped taking it or even faked taking it in school.  They developed strategies for coping in the world and were able to achieve academic and vocational success.   Even some of the strongest proponents of medical treatment of ADHD will agree that proper care also involves lifestyle and management strategies and in some cases formal therapies in addition to medication.  That does not mean that some people will not do better with medications and worse with lifestyle modification, but it does mean that there is much more latitude in the treatment of this disorder than is commonly assumed.  It is fair to say that in many clinics these days, there are clinicians actively looking fro any treatable psychiatric disorder.  The theory seems to be: "If I treat the social anxiety disorder, bipolar disorder, ADHD, panic attacks, and insomnia this person will be a lot better off."  There is really no evidence that this is true or that there is even a good way to select what disorders should be treated first.

The patient side of this problem seems to be the myth of the perfect mind extended to many conditions.  It is evident in a number of ways.  Some people present with some very basic knowledge of psychopharmacology.  They may suggest that their "serotonin" or "dopamine" is out of whack and that they heard that there are specific medications to correct that.  In some cases they will suggest a medication.  In other cases, a person will not be very stress tolerant and suggest that they need something that will either reduce day to day stress or significant stress from predictable major life stressors like the disruption of a job or relationship.  They seem to think that there is a medication that will both reduce the emotional reaction to this pain but also remove the cognitive elements from their mental life.  Depending on the person's baseline cognitive state, they can become quite demanding if they think that they are not getting adequate relief or it is not happening fast enough.  The risk in these situations is starting to take a number of medications with substantial side effects that frequently precludes them getting back to their baseline conscious state.  There is often a focus on a person's baseline in psychiatry or medicine, but that baseline is almost never adequately characterized.  That is true in the case of blood pressure but more true in the case of mental illnesses.  In the case of severe mental illnesses like bipolar disorder baseline is almost always defined in terms of the presence or absence of a few symptoms.  Wide areas of a person's life like their baseline intellectual functioning, social behavior, and typical stream of consciousness are rarely considered - even in research studies.

Addiction makes everything worse and therefore it also provides the best illustration.  The graphs at the top of the page show two drug response curves with the blue lines showing a good response.  A person who is using an addictive drug and the high risk response to that drug is conditioned to expect the drug response curve on the right - a continued therapeutic response for increasing doses of the medication.  In that case there is no element of safety or toxicity.  True drug responses are represented by the curve on the left - an interval of response followed by toxicity and limited response at the higher levels.  Addictions have a second effect by creating a bias that mental states can be fine tuned within the space of hours by drugs.  Any feeling state can be immediately modified by the addition of benzodiazepines, stimulants, opioids or alcohol.  This is often erroneously referred to as "self-medication" and it is a strong conditioned response that generalizes to the treatment of disorders with non-addicting drugs.

The psychological effects of these patterns are significant.  They can lead to continued addiction and disrupted care.  A person may have the belief: "If this doctor can't give me something that will get rid of the negative way I feel right now - I will take something to get rid of it."  It may lead to disruption of the therapeutic alliance, through anger and open criticism about the lack of immediate effects or minimization of physician concern about side effects and a general lack of concern about toxicity on the part of the patient.  There is often an associated belief: "I have a very high tolerance for drugs and you can give me higher starting doses and higher maintenance doses of drugs than you give most people."  Many people in this situation experience very high levels of anxiety if they are not getting high doses or the physician does not seem to be increasing the medication fast enough.

The thoughts and feelings about medications is one of the most difficult areas in psychiatry.  Contrary to what is written by critics - nobody is complaining about being overmedicated.  Most of the complaints I hear about are about not getting enough medication and not getting to those high doses fast enough.  The solution is rarely to provide the medication and amount requested.  The solution is to spend enough time talking with the patient about these issues.  I generally start with the limitations of the defined treatment and a medication strategy that is risk avoidant.  In that initial conversation I usually tell the person whether or not they have a diagnosis or if I agree with a pre-existing diagnosis.  If I detect signs that unrealistic expectations about the medication are present I move into that area, point out that the medication will not lead to a perfect mind, and what they have to do in addition to taking medication.  If I find that they are really focused on medication issues to the point that they are experiencing anxiety from it - I usually encourage them to think about something else and provide some examples of what else can be done.

There is some literature on psychodynamic issues and medication in the transference that I have not found very useful. I suppose you could say that from what I have written the medication has meaning far beyond its pharmacology.  There is an interpersonal and intrapsychic context.  I think it is addressable in what is usually considered straightforward supportive psychotherapy, but it definitely needs to be addressed.  It is a frequent cause of medication or treatment "failures".


George Dawson, MD, DFAPA