Spare The Venlafaxine.....

Venlafaxine is a commonly prescribed second-generation antidepressant. It is well-known to psychiatrists because it is a second line medication if SSRIs fail and for many psychiatrists it is another first-line antidepressant. In some head-to-head comparisons with SSRIs venlafaxine has a more favorable side effect profile. It does have the risk of discontinuation symptoms and typical antidepressant side effects. I have noticed that the dose escalation with venlafaxine seems to be out of proportion with SSRIs, bupropion, and third-generation antidepressants.

Consider the following venlafaxine related scenarios:

1. A colleague comes into my office late in the day and asks me: “Have you ever heard of venlafaxine causing sedation at higher doses?” The patient in question was just increased from 187.5 mg to 225 mg - the suggested max dose according to the FDA approved package insert. 

2. I am asked to consult on patient who had extensive pharmacogenomic testing in a different facility where she was told that she may need to take 350 to 450 mg of venlafaxine per day based on that genetic profile. She wants to make sure that she gets an adequate dose of the antidepressant and is currently on 225 mg.  I reviewed the limitations of that approach with the patient and potential side effects and I let her know that the commonest side effect I see in people taking high-dose venlafaxine is excessive sedation or low energy in the daytime. As we start to follow the recommended dose increase she discloses that she has had sedation even at the 225 mg level. We decreased the dose to 150 mg and that side effect is gone.  Her depression is also gone.

3. I see a significant number of patients taking more than 300 mg per day of venlafaxine from the same geographic location in the United States. They all tell me that the target dose in that location is 350 mg per day and they are all experiencing numerous side effects. Many had dose escalations into that range in a week or two - much faster than any increase I have done.

What is wrong with this picture? Why are there a significant number of people taking more than the recommended dose of venlafaxine in some cases much more and appearing to have side effects? The roots of this prescribing behavior can be traced back to old-school psychopharmacology. Proponents of that approach suggests that there may always be a group of outliers that need to take higher-than-expected doses of medications - typically antidepressants but there has also been a history of excessive dosing of antipsychotic medications. People were generally more cautious with more toxic medications like tricyclic antidepressants, monoamine oxidase inhibitors, lithium, and various addictive compounds. They also seem to be more cautious with SSRI type medications at least initially. It took over a decade for me to see a dose of sertraline in excess of the maximum recommended dose.  While it is true that there are always outliers in terms of dose-response what is the best way to approach that problem.

I have attended medical education courses where the lecturer suggested titrating the medication to the point of toxicity and then reducing it back down to the next lowest dose. That particular lecture was focused on treating anxiety disorders with SSRIs. I don’t think that is the best approach. The best approach to me is one where the patient recovers from anxiety or depression and the process does not experience a single side effect. I know that can be done because I have been doing it for decades.

That also brings me to what I think is a good research article that looks at optimal dosage ranges. It is a very large meta-analysis of fixed dose randomized clinical trials that utilize the specific antidepressants - citalopram, escitalopram, fluoxetine, paroxetine, sertraline, venlafaxine, and mirtazapine.  The trials were identified by searching the literature and looking for unpublished studies specifically by searching national drug licensing agencies and requests directly to pharmaceutical manufacturers. Outcomes were noted at eight weeks of treatment and defined as a 50% reduction on an observer rated scale for depression.  Dose equivalence among medications was determined from previous studies and the recommendations of the manufacturer. The article is written by researchers that I consider to be world experts in meta-analyses and the analysis of large data sets in psychiatry.

77 studies were identified from a total of 24,524 published references and 4030 unpublished records.  27 were published, 21 or unpublished, and 29 were both published and unpublished. The study showed too hard when treatment groups across all of the medications of interest between the years 1986 and 2013.

The authors calculated dose response, dropouts due to adverse effects, and dropouts for any reason. Relative risks (RRs) were calculated for specific doses. The dose outcome relationships for venlafaxine are included in the figures below from the original article.  The Response figure shows the significant increase of up to about 150 mg and then a much more modest increase beyond that. The Dropout figure shows a similar increase up to the 150 mg range. The Dropout for any reason was less remarkable. The authors calculated that the 75-150 mg dose of venlafaxine was equivalent to 20 to 40 mg of fluoxetine (click to enlarge graphic)

The authors conclude that optimal acceptability of SSRIs and venlafaxine and and mirtazapine occurs within the lower end of the licensed dose range. They reconcile this with serotonin transporter (SERT) studies that show that 80% SERT occupancy occurs at the minimum doses of SSRIs or venlafaxine with further dose increases showing small increase in SERT occupancy.

In the case of venlafaxine they suggest that noradrenalin reuptake transporter (NET) may require higher doses of venlafaxine in the 225 mg to 375 mg per day range. Given the lack of efficacy of atomoxetine, a logical question might be whether NET blockade adds much to the antidepressant effect.

The authors review other dose-efficacy studies of antidepressants and point out that they are variable. The variability ranges from optimal doses of fluoxetine in the 21-40 mg per day range to doses at the recommended lower end of the range being superior. Response to doses in the higher range were variable in some studies. One study found a significant greater response for high-dose antidepressants but the dose of 40-50 mg fluoxetine equivalents showed the greatest efficacy.

The authors considered strengths and limitations their study. They thought that their state-of-the-art meta-analysis was a strength as well as the size of the data set. They also examined dose dependency for both efficacy and tolerability and acceptability. The limitations they discussed included patient selection and dosing not reflecting clinical practice. They also discussed the calculation of dose equivalency among antidepressants and how that might be problematic.

Another obvious strength of this study is the calculation of relative risks for response across SSRIs, venlafaxine, and mirtazapine. The figures are modest but favor antidepressants across all dosage ranges with the exception of mirtazapine at the 60 mg dose.  The authors don’t seem to mention it but it would seem that the optimal dosage ranges could be predicted from the regulatory information since that is based on dose ranging studies and tolerability studies. In that regard, the conclusion about dose ranges don’t seem to be that surprising but they may be needed given what is happening clinically.

Getting back to the issue with venlafaxine I see people respond to dosing within the lower and of the range from 37.5 to 75 mg in many cases. That same response rate continues up to the 150 mg dose and then starts to diminish between two or 25 and 375 mg. Over that same range there is a significant increase in dropout rates due to adverse effects.

How clinicians approach this new information will be interesting. There will still be people like me and the conservative camp looking for the first signs of side effects and toxicity and deciding at that point whether to stop dose escalation. I explicitly tell people that the goal is not to experience any side effects and that I doubt that people “get used to” side effects. There are clearly clinicians out there who are doing exactly the opposite and that is increasing the dose of venlafaxine and advising people to either tolerate the side effects or expect that they will go away.

The balance between therapeutic effect and side effects is a central issue in all branches of medicine. In many cases, the severity of adverse effects like an allergic reaction determines the decision. In the case of the medication like venlafaxine making that decision can be complex. Some of the side effects like sedation and lethargy at high doses can mimic symptoms of depression. At this point in time neither pharmacogenomics or most plasma level determinations guarantees either tolerability or efficacy.  

Detailed analysis of the situation by an expert with a bias toward preventing side effects is required as the first step in any dose increase.

George Dawson, MD, DFAPA

References:

1:  Furukawa TA, Cipriani A, Cowen PJ, Leucht S, Egger M, Salanti G.  Optimal dose of selective serotonin reuptake inhibitors, venlafaxine, and mirtazapine in major depression: a systematic review and dose-response meta-analysis.  Published:June 06, 2019DOI:  https://doi.org/10.1016/S2215-0366(19)30217-2.

Attribution:

Above figure of the venlafaxine dose response and drop outs are directly from the paper in reference 1 and used per the Creative Commons Attribution 4.0 International Public License.

Attribution 4.0 International (CC BY 4.0)

Attribution 4.0 International (CC BY 4.0)

Chemical Imbalance As Advertising Meme

After a protracted discussion on the previous post, I thought I would go down to the University of Minnesota Biomed library today and look at the drug ads in psychiatric journals at about the time Prozac came out in 1987. I was interested in the trends before and after so I picked the years 1985 to 1995. I also picked the journals the American Journal of Psychiatry, Archives of General Psychiatry (currently JAMA Psychiatry), and the Journal of Clinical Psychiatry.  I was going to include JAMA and the New England Journal of Medicine.  They had about the same number of ads but none of them in that year contained ads for psychiatric medications.

This kind of search is labor intensive these days. There was a time on the early days of the Internet when entire journals with all of the ads were scanned in. As a subscriber I could have run that search from home.  These days, all of the ads are gone and the references are saved as text files only. In order to see historical ads - the hard copy of the original journal needs to be examined. Even then there are some problems.  I encountered some bound volumes where the ads were physically removed. There were two to three bound volumes per year and additional copies of the NEJM and JAMA - I may have looked at 75 bound volumes over 4 hours.

In many ways it was a walk down memory lane.  Clozaril and Haldol Decanoate ads were especially heavy in the early 1990s.  There were ads for medications that I prescribed all of the time like Navane and Pamelor and ads for drugs that I seldom prescribed like Stelazine, Serzone and Luvox. There were ads for new drugs that I would prescribe once like Paxil.  It was a reminder that despite all of the advertising - a  lot of drugs end up never being prescribed by physicians.  My reason for being there was to look for the origins of the term "chemical imbalance" in this advertising.

I decided to embark on this project because of all of the inaccuracy about the term, especially the tendency to blame psychiatrists for it. In my previous post, I attempted to point out that it is a fairly straightforward process to conclude that the human brain does not run on chemical imbalances - just based on the average scientific knowledge of physicians. On the advertising side, I was there for the first National Depression Screening Day in 1990 and that was the first time I heard the term. The event has been criticized as a venue for allowing a pharmaceutical company to showcase their product.  I participated in the event for 3 years and the advertising involved was much more subtle than is found today at NAMI walks for example. But the question is whether the advertising meme "chemical imbalance" was introduced at that time. Any event that happened 30 years ago is very hard to track. As the Public Affairs Rep for my District Branch of the APA, I had a lot of files about it that I subsequently trashed. I am guessing there were also some files on disk drives that would have been helpful.  This is a reconstruction without that data.

I successfully located the first Prozac ad in AJP from 1988.  The graphics are all iPhone photos so there is some distortion.  Chemistry is emphasized on page one as in the chemical structure, chemically unrelated to other antidepressants, distinctive chemistry, and the first highly specific and highly potent blocker of serotonin reuptake.

Why is this important? At the time most of the antidepressants being used were tricyclic antidepressants.  They could not claim any specificity and in subsequent ads manufacturers start to compare possible side effects based on transporter monoamine protein and receptor affinities. The Prozac molecule was being hyped as being chemically unique and with a better side effect profile. As Prozac started to sell more it became a blockbuster drug for Eli Lilly and at that point the manufacturers of other new antidepressants noted and the competition heated up.  There were some direct references to Prozac in the ads from competitors.

The best example is this Wellbutrin ad from AJP in 1991. Prozac is directly mentioned in the ad and reasons are given for choosing Wellbutrin over Prozac.  Being non-serotonergic is one of them and this is more of a counter to Prozac advertising as being a unique first highly selective serotonergic drug.  It gives little or no weight gain as a reason, but at the time I was seeing obese patients who were taking 80 mg of Prozac because their primary care physicians told them they could lose weight taking it. Of the other bullet points it seems that lack of sexual dysfunction would be  the most relevant. The marketing decision in this case was a conscious decision to go after the purported serotonergic effects of Prozac rather discuss the hypothetical mechanism of Wellbutrin.  The side effect of Wellbutrin that most physicians are concerned about - seizures - is in the smaller print below the bullet points.

Effexor came up with similar ads.  In the late 1980s and early 1990s, synaptosome technology was invented to look at binding affinities of central nervous system medications to specific receptor sites.  The quantitative aspects of these studies were generally globalized in the psychiatric literature to qualitative ballpark effects.  For example a plus or minus grading system could be used ranging from no effect at a receptor (-) to a robust effect (++++).  Effexor advertising used this to compare side effect profiles among the competitive antidepressants at the time.

This ad emphasizes that Effexor is "a structurally novel antidepressant and is chemically unrelated to any other available antidepressant."  It shows the table with comparisons to tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs) and what might be predicted based on the in vitro synaptosome data with the qualifier that the clinical significance of that data is unknown.  Clinically most people are able to tolerate all three classes of medication but some will not.  The differences can't be predicted on the basis of the receptor binding studies because of receptor heterogeneity and differences in drug metabolism.  For example, I still prescribe TCAs. It is nortriptyline and it is the only one I have ever prescribed. At the doses I prescribe and per the table in the ad - it is as well tolerated as SSRIs and SNRIs (Effexor).  The ad appeared in the AJP in April of 1994.  On that basis the argument could be made that it is an appeal to the technical expertise of psychiatrists and it should contain this information.  That also points to a weakness in my informal advertising study and that is a lack of ads from the non-technical consumer literature from the same period. (see supplementary on a proposal).

I have 30 additional ads from the journals but the themes are roughly the same. An emphasis on medicinal chemistry and the suggestions that some chemistry is better than others. Interestingly, in my previous post the whole point was that this is the kind of argument that would not fly based on what the average physician knows about chemistry and molecular biology. Psychiatrists should know a lot more because the evidence for and against these theories had been reviewed in the psychiatric literature 20 years before these ads came out (1974-2002) (1).  And they are engaged in clinical practice and need to be skeptical of newly introduced products and claims.

What I did find so far is unequivocal evidence that the chemical imbalance meme was used to directly market antidepressants to the public.  The Zoloft ad embedded at the top of this page from 2001 is the first example.  The second example is this Paxil ad from the same year.

That is what I have so far.  See the Supplementary below to find out what you can do to complete the story. I don't have a problem with people telling me that their doctor told them that they have a chemical imbalance and their antidepressant is supposed to treat that. I don't have a problem with people saying that their psychiatrist told them that.  I do have a problem with people saying that all or even most psychiatrists say this and that psychiatrists are behind this meme.

There is an exaggerated focus on the mechanism of action of medications used for psychiatric indications. I have never heard anyone say their doctor told them about the mechanism of action of antibiotics or even their blood pressure medications. In the case of antibiotics it is clear that people demand them and they don't care what the risks or mechanisms are.  This advertising campaign may have something to do with the conversion of folk psychologists to folk psychopharmacologists.  A friend of mine also brought up an important aspect of this campaign that is also addressed by these manufacturers and that is legitimacy. For decades people with depression and anxiety were viewed as weak people with a questionable problem.  My friend told me that these ads confirmed that she had a serious problem that needed a serious solution and that it was finally acceptable to talk about it.  Say whatever you want about Big Pharma advertising but it apparently carried the message that current "Let's Talk About Mental Health" programs do - but over 15 years ago.

The attribution of an advertising meme to psychiatry and psychiatrists despite the fact it has never appeared in 30 years of psychopharmacology texts is not a trivial fact.  The advertising videos posted here  were viewed by tens of millions of people.  I hope to get more information and still have some people to contact. With any luck I will be able to fill in the additional data between the release date of Prozac in 1987 and the ads posted here from 2001.

Please send me anything you might have from those dates.



George Dawson, MD, DFAPA


References:

1.  Nathan KI, Schatzberg AF. Mood disorders. in Review of Psychiatry, vol 13. American Psychiatric Press, Washington DC(1994): p.171-184


Supplementary 1:

From the  information I posted above it is clear that chemical imbalance was an advertising meme introduced during the height of competition of blockbuster  antidepressant drugs.  The  common Wall Street definition of a blockbuster pharmaceutical is a product that generates sales of a billion dollars a year.  There are two important pieces of data that would be useful to complete the story.

The first is earlier ads with the term chemical imbalance. So far, I have two from 2001, but I am certain it appeared before that. I don't have time to search all of the popular literature.  If you subscribe to a magazine that has pharmaceutical advertising and keep all of the old volumes - take a look at the editions from about 1987 to 1995. If you see the term chemical imbalance please send me the image with the name and date of the periodical.  Let me know if you want credit for finding the image and I will give you full credit.

If you are a current or former pharmaceutical rep or marketing person and have access to any documents or videos with the chemical imbalance phrase please send it to me with the date it was being used. If you have recollections of how it was implemented and when I can also use that information but I am most interested in clear documentation like the videos I have posted. I have no interest in vilifying the pharmaceutical industry and understand the need for marketing and advertising.  I am just interested in the origins of this term and how it was implemented.

If you are an APA member and you were involved in the original National Depression Screening Day in 1990 - you may also have some information about this.  Please send it to me.

Thanks!


Supplementary 2:

All of the name brand drugs/medications mentioned in this post are currently generics or are no longer manufactured.  I have no affiliation with the original manufacturers or the generic drug industry.


Supplementary 3:

There are various Internet sites that attribute the term chemical imbalance to Pfizer or Lilly but they do not appear to be reliable - many appear to be antipsychiatry sites.  I would like to hear from people who were there at the time and can provide the necessary proof.  In those days (1986-1996) it would have been an internal memo or presentation.  Send me a copy if you have it.


Supplementary 4:

I had the opportunity to discuss this issue with a corporate attorney - especially the issue of available emails and memoranda dating back to 1987.  He told me that corporations hold this data only as long as the law states they needs to.  For example, if the law states the data must be held for 4 years it will be held exactly that long and then everything will be shredded.  If this information exists it will probably be in private hands.

Supplementary 5:

I got the expected low level feedback from a Twitter poster who thought he was making some point about this link on the Royal College of Psychiatrists web site suggesting that at least one of the causes of schizoaffective disorder was "a chemical imbalance".  I guess he really thought he had made me look foolish especially with the proclamation "You aren't psychiatry - they are."

https://www.rcpsych.ac.uk/mental-health/problems-disorders/schizoaffective-disorder

In fact, I can't tell who wrote this and whether or not it is a psychiatrist. I don't know what the RCP official position is.  I was happy to see that they are much more flexible than the anti-psychiatry Twitter posters I encounter.  There was a feedback form that I completed and advised them to lose the "chemical imbalance" and that replacing it with "unknown etiology" was preferable. What I would like to see is an exposition of the latest theories and a suggestion that the critics actually read psychiatric literature.  They would be less likely to perseverate the same criticism they have used for year after year. This poster also seemed to ignore the fact that the RCP public information was posted in 2015 - that's 14 years after the television ad posted at the top of this page.  Royal College of Psychiatrists - the ball is in your court.

Supplementary 6: (added on 1/11/2020):  I just learned today from an advertising expert in antidepressants that there was also a Zoloft ad from 2004 that used the term: 

"While the cause is unknown, Zoloft can help.  It works to correct a chemical imbalance in the brain that may be related to these symptoms."

Reference:

Cristina Hanganu-Bresch. Treat Her with Prozac: Four Decades of Direct-to-Physician Antidepressant Advertising in Drugs Media: New Perspectives on Communication, Consumption, and Consciousness (Hardback) (1st Edition) by Robert C. Macdougall (Editor), Drugs &. Media-Pasta Dura, 340 Pages, Published 2011 ISBN-10: 1-4411-1988-4 / 1441119884 ISBN-13: 978-1-4411-1988-9 / 9781441119889:

The Non-Existent Chemical Imbalance Theory

I keep looking for it and can never find it.  The above picture is my stack of psychopharmacology texts dating back to about 1980 and none of them mentions "chemical imbalance".  I could add another foot or two to that stack and there still would be no mention of this theory.

Why is that important? The main reason is that one of the favorite arguments by anti-psychiatrists is that real psychiatrists believe that psychiatric disorders are caused by a “chemical imbalance” in the brain. This criticism showed up on this blog several years ago in a post that I critiqued that was largely a screed against psychiatrists. Accusing psychiatrists of promoting a chemical imbalance theory is an almost perfect rhetorical strategy. It uses what essentially was a marketing device for antidepressants in the late 1980s to portray psychiatrists as excessively reductionist at the minimum and at the worst biologically naïve and dishonest.

My colleague Ron Pies, MD has written a recent piece on the historical, philosophical, and rhetorical aspects of this argument. What I hope to accomplish in this post is taking a look at the science behind why no psychiatrist would consider the brain to be a substrate run by “chemical imbalances”. Some might find this argument to be quite boring but I can attest to the fact that the premises used allowed me to state unequivocally to the first pharmaceutical rep to use the term that no such state exists in the brain.

The main factor has to do with how physicians are trained. There’s still a lot of confusion about whether a psychiatrist is a physician or not. I can assure anyone reading this that we all are. That means in order to get into medical school certain prerequisites at the undergraduate level have to be completed. That includes a year of general chemistry, a year of organic chemistry, and a year of general physics. A significant number of psychiatrists that I have encountered were chemistry majors. That training means that physicians in general have had exposure to physical science and how chemistry works in solutions and gases.  In these basic two or three component systems there are limited possibilities in terms of reaction outcomes. Even electrochemical reactions produce electron flow that decays predictably over time but that is not able to transmit any nuanced signal.  In other words the information content in these systems is low – too low to run biological organisms.

In the basic science years of medical school biochemistry, neuroanatomy, neurophysiology, pharmacology, and all of the associated molecular biology provided medical framework that all of the physical science can be mapped onto. The study of enzyme and receptor systems highlight the basic concept that the chemistry involved can only occur because it is in a specific microenvironment. That microenvironment includes the protein structure of the enzyme or receptor molecules as well as associated membrane components and cell signaling components. The intracellular and extracellular environments are exquisitely controlled as is the synaptic cleft. Many of the reactions involve additional acid-base and ionic gradients. The degrees of freedom in these many component and many phase systems are large. They are so large in fact that I have been unable to find an estimate of degrees of freedom for neurobiological systems.

A good example of the kind of microenvironments and complex interactions that I am taking about is the GABA_A receptor depicted diagrammatically below. The GABA_A receptor is a transmembrane cylindrical receptor that is a member of the pentameric ligand-gated ion channel superfamily.   The diagram is a top down view of the receptor complex cylinder highlighting that it is composed of 5 glycoprotein subunits.   Each subunit is composed of 4 domains with one domain that lines the chloride ion channel through the center of the receptor complex. Binding sites on these protein allow for allosteric modification of the cylindrical receptor to facilitate chloride ion influx and fast inhibition of neuronal signals.  Allosteric modulation of enzymes and receptors occurs when a molecule reversibly binds to the protein molecule resulting in inhibition or stimulation of the overall process.  For example, benzodiazepines bind to a specific site at the α-γ interface leading to increased affinity for GABA at the receptor sites and increased chloride ion influx. Benzodiazepines are the classic allosteric modulators of the  GABA_A receptor but there are others.  Barbiturates, anesthetic agents, neurosteroids and ethanol are also allosteric modulators at the GABA_A receptor.  The detailed structure of both the benzodiazepine and flumazenil binding sites on the human synaptic GABA_A receptor have only recently been detailed (1). 

The above paragraph is a glance into the types of systems that modern psychiatry is focused on.  In the case of the GABA_A receptor global inhibitory effects can be expected at some point, but there are not the product of chemicals floating about inside the body or brain. They are the effects of complex interactions between proteins, positive and negative modulators, neurotransmitter effects, ion fluxes, and additional signaling.  The effects result from where these receptors are located in the brain and central nervous system. The education of physicians assures that this level of complexity in the brain is appreciated as both the basis for normal physiology and also the basis for pharmacology and toxicology. It may be tempting to try to simplify things - but real brain function defies simplification.  The basic working of the GABA receptor was discovered when I was in medical school back in the 1980s. The lectures in those days showed a simple structure with an arrow showing increased chloride ion permeability but nowhere near the structure that we currently have. 

This is one set of receptors and modulators very simplified. To get more of the story read the 22 pages of reference 1.  To understand the brain and modern pharmacology much more needs to be understood. Forgetting about the term "chemical imbalance" is a good first step.

George Dawson, MD, DFAPA

References:

1: Zhu S, Noviello CM, Teng J, Walsh RM Jr, Kim JJ, Hibbs RE. Structure of a human synaptic GABA(A) receptor. Nature. 2018 Jul;559(7712):67-72. doi: 10.1038/s41586-018-0255-3. Epub 2018 Jun 27. PubMed PMID: 29950725; PubMed Central PMCID: PMC6220708.

2:  Human GABA-A receptor alpha1-beta2-gamma2 subtype in complex with GABA and flumazenil, conformation A.  Detailed structure from the above paper.

Suicide Risk After Hospital Discharge

Inpatient psychiatrists in the United States deal with three problems: suicide risk, aggression risk, and the inability care for oneself or impaired functional capacity. Those have always been the primary reasons why people are admitted to psychiatric hospitals. Over the past 30 years there has been a problem with business intruding on these medical indications. Businesses and or more specifically managed care companies eventually adopted a single codeword “dangerousness”. Dangerousness was supposed to encompass all three of the dimensions but eventually it developed a life of its own. As an example, I have been asked by insurance company reviewers “Where’s the dangerousness?” whenever they tried to throw one of my patients out of the hospital and onto the street. Science or medical principles were not involved, just the economics of being able to use a word to make money.

The reality of inpatient work is that the people there are very high-risk for suicide, aggression, and premature death from multiple causes. There was a study done in Germany about 20 years ago where they looked at all-cause mortality of people discharged from psychiatric units five years later and the number was very high. Post discharge suicide rates are much higher than suicide rates in the general population. These high numbers are expected because patients and inpatient units are selected for these traits that predispose to higher mortality and morbidity. The trends have been complicated by much shorter lengths of stay and bed limitations that means patients with severe mental illness may be refused admission even if they clearly need it. As example, since leaving the inpatient setting about 10 years ago, I have attempted to refer severely ill patients to psychiatric hospitals and they were turned away at the emergency department. In some cases they were turned away without being seen by a physician. There are probably a handful of psychiatrists in the United States who know the type of problem that needs to be treated that inpatient units and I am one of them.

That situation makes a recent study on risk of suicide after discharge from inpatient psychiatric care and interesting one. The study was done in Sweden. It encompassed the years 1973 to 2009. During that time there were 2,883,088 admissions and presumed discharges. 690,937 patients were discharged more than once. Most the discharges were men (57.6%). There were no explicit indications for admission. Patients were followed up and it was determined that there were 3695 suicides within 30 days of discharge. The authors calculated a suicide rate of 181/10,000.  The discharge diagnosis most associated with suicide with depression. They gave some rough estimates of the prevalence of disorders in this population: 34% alcohol use disorder, 15.5% had mood disorders and (bipolar disorder or depression) and 9.9% had schizophrenia. 

Looking at the results according to diagnosis depression was followed by reaction to crisis or what is probably called an adjustment disorder in the US, but any specific psychiatric disorder and elevated hazard ratio for suicide within the first 30 days of discharge relative to the diagnosis of alcohol use disorder. 

Suicide risk was also examined relative to recent suicidal behavior. The suicidal behavior was considered to be any deliberate self-harm less than 30 days prior to admission. That was noted to have a hazard ratio of 4.75. The diagnoses were re-examined in the context of deliberate self-harm prior to admission and the risks were significantly higher in schizophrenia (HR = 8.94) and other nonorganic psychosis (HR =6.82).  Interested readers are referred to the full text which is available free online for the specific details including hazard ratios and confidence intervals for those hazard ratios.

The main findings of this study include the association of relatively high risk at discharge for most diagnoses and much higher risk if a specific diagnostic category was associated with a self-harm event 30 days prior  to admission.  This confirms clinical risk assessments that are typically done and also the fact that this is a high-risk population.

The authors do state that they regarded principal diagnosis at discharge to be the best available information on the reason for admission. I contacted the corresponding author about this and he did confirm that the reasons for admission in Sweden are very similar to what they are in the United States and that is suicide risk, aggression risk, and ability to care for oneself - but those specific metrics were not listed in the paper. 

The authors speculate on why the suicide risk is high. They describe the slow recovery from depression and the clearing of psychomotor retardation prior to the resolution of depressogenic thinking.  In the US, psychiatrists are generally taught that psychomotor retardation may reduce the risk of acting on suicidal thoughts so that during treatment there may be a point where activation may put the person at risk for acting on unresolved suicidal thoughts. Given the characteristics of suicide particularly the impulsivity associated with it this progression of events has never been proven and remains highly speculative. The authors also had the interesting observation that crisis events or negative life events are expected to offer good prognosis but this study showed men with the diagnosis of reaction to a crisis were at high risk after discharge irrespective of whether there was any recent suicidal behavior.

The authors review the strengths and limitations of the study. The main strength is that it is a large-scale study with a significant number of suicides. They also point out how their study has similarities with other studies of suicide in hospitalized patients. On the limitation side most of the limitations had to do with a lack of granularity in the data. I pointed out the lack of specific admission indication in addition to diagnosis. In current databases there may be metrics having to do with the level of suicide or aggression risk. There are some large-scale studies being done on an outpatient basis looking at those metrics as well as supportive interventions based on risk scores.

The biological side was not discussed in this study even though the database used probably contained all of the admission and discharge medications. It would be interesting to know if certain pharmacological interventions were more or less associated with suicides after discharge. It would also be very useful to know if there were any protective factors from inpatient treatment that could be discerned from the data both from the standpoint of psychosocial interventions and biological interventions like electroconvulsive therapy, transcranial magnetic stimulation, or treatment with ketamine.

I have included a reference to another study of post discharge suicide rates done in a Medicare sample and with a slightly different methodology (2).  In this case the researchers looked at a population of 770,643 patients with mental disorders compared with a 1,090,551 patients in a cohort with no mental disorders and compared suicide rates in the first 90 days after discharge. They found suicide rates that were 10-20 times higher in the mental disorder cohort.  The non-mental disorder cohort had a rate that was lower than the baseline suicide rate in the US at the time (11.6 versus 14.2 per 100,00 person years).  Like the Swedish study rates were the highest for mood disorders. Comparing both of these studies would be an interesting seminar for residents or journal club for staff psychiatrists interested in different epidemiological approaches to the same clinical problem.  I have included two references by Chittaranjan Andrade, MD and encourage the use of his series on statistics and epidemiological concepts in the Journal of Clinical Psychiatry.

From a clinical standpoint, the take-home message for clinicians is to make sure that deliberate self-harm prior to admission and the diagnosis are carefully explored. It is fairly common practice to consider adjustment disorders to be low risk in terms of brief hospital stays and discharge plans that do not include intensive outpatient treatment. This study suggests that at least some of those patients need more intensive intervention but there is no guidance on how to identify that group. The other high-risk groups of patients with psychosis that had deliberate self-harm prior to admission and any trained inpatient psychiatrist should admit those patients and treat them until there is clinical improvement that results in decreased risk.

My only concern about the current patient flow through emergency departments and onto psychiatric inpatient units is that many of these patients never get admitted and if they do they are discharged in a short period of time with the same symptoms that they presented with.  The inpatient environments in the US are also deteriorated to the point that they resemble correctional settings and patients want to leave as soon as possible.

These are not good ways to address the issue of post hospitalization suicide risk in a high risk population.

George Dawson, MD, DFAPA

Reference:

1:  Haglund A, Lysell H, Larsson H, Lichtenstein P, Runeson B. Suicide Immediately After Discharge From Psychiatric Inpatient Care: A Cohort Study of Nearly 2.9 Million Discharges. J Clin Psychiatry. 2019 Feb 12;80(2). pii: 18m12172. doi: 10.4088/JCP.18m12172. PubMed PMID: 30758922. (full text)

2: Olfson M, Wall M, Wang S, Crystal S, Liu SM, Gerhard T, Blanco C. Short-termSuicide Risk After Psychiatric Hospital Discharge. JAMA Psychiatry. 2016 Nov 1;73(11):1119-1126. doi: 10.1001/jamapsychiatry.2016.2035. PubMed PMID: 27654151. (full text)

3: Andrade C. Why odds ratios can be tricky statistics: the case of finasteride, dutasteride, and sexual dysfunction. J Clin Psychiatry.2018;79(6): 18f12641. Link

4: Andrade, Chittaranjan. Drug interactions in the treatment of depression in patients with ischemic heart disease. The Journal of Clinical Psychiatry 73.12 (2012): 1475-1477.

Deprescribing - Same Job With A New Spin

During my tenure as an acute care psychiatrist, I had to reconcile a lot of medications. I was doing medication reconciliation before the term was invented for the electronic health record (EHR). The process basically involves trying to figure out what medications the patient was really taking before they were admitted to the hospital. It could be very easy if there were no preadmission medications. On the other hand it could be extremely complicated. There were days when I had to sort through two or three shopping bags full of medications, talk with the patient’s pharmacist, talk with several specialists who were prescribing medications, and talk with the patient’s primary care physician. Even after that long process, I often estimated initial dosages based on the patient's recollection of what they had been taking and how much. I also had to make fairly rapid decisions about whether or not large numbers of medications may have been more harmful to the patient than helpful. Some patients had lists of medications containing 10 to 20 unique medications.

Sometime in the past 10 years the concept of deprescribing medication came up. It is fairly unique term as indicated by the bar graphs below that are drawn based on the references per year to the term. It started out the geriatric literature because elderly people are more sensitive to lower doses of medications and polypharmacy relative to younger and healthier populations. There is actually a list of medications called Beer’s list, that highlights medications that may be more problematic in older adults. It is the intellectual property of the American Geriatrics Society and I can’t reproduce it here. It basically contains classes medications that are known to be problematic in older adults such as anticholinergics and sedative hypnotics. Consistent with that concept - the geriatrics literature has focused on rational pharmacology and the need to reduce the medication burden in some cases the specific pharmacodynamic burden of prescribed medications.  Goal of this post is to look at some of the techniques I typically use to identify polypharmacy - related problems and respond.

In determining whether deprescribing should occur or not I think it is useful to look at hierarchy and I have outlined the following points:

1. In the case of the patient on polypharmacy who is tolerating multiple medications well and they appear to be effective strongly consider doing nothing:

Being an expert in psychopharmacology - doing all the reading and listening to the experts often doesn’t translate into the real world setting very well. There’s no better example than the patient on multiple medications who frequently has a history of numerous or prolonged hospitalizations and who appears to be taking “too many medications”. They could be multiple medications from the same class or different classes. It is easy to take a look at that list of medications and imagine how they came about but with our current fragmented medical record system it would only be an imagining.  It is too high of a risk to stop polypharmacy just based on general principles if the patient is doing well. I am familiar with many cases where changes were made and the patient became markedly destabilized and ended up back in long-term hospitalization. These are the cases that never come to light in the literature where populations rather than outliers are studied.

2. Acute medication side effects: 

In the case of acute side effects changes need to be made based on the urgency involved. Worst-case scenarios would include serotonin syndrome or neuroleptic malignant syndrome where the serotonergic or dopaminergic medications need to be stopped abruptly. That would not occur in typical clinical scenarios but in the emergency setting it is necessary. What clinicians typically face is multiple medications from the same class. When that original guideline was made back in the 1990s classes were a lot more general than they are now. For example, in those days antidepressants were a general class instead of SSRIs, SNRIs, and others.  These days combination antidepressant therapies are relatively common and research articles can be found that look at the addition of bupropion to a standard antidepressant or mirtazapine to a standard antidepressant. Beyond that trazodone might be added to those two antidepressants bring the total to three. This can occur commonly in clinical practice and also can be a source of the patient noted in number 1 above.

Numerous side effects can result from polypharmacy like sedation, headaches, nausea, and cognitive problems that probably indicate the total amount medication needs to be decreased or at least one of the medications could be stopped. The medication I frequently encounter that is prescribed at very high doses resulting in sedation is Venlafaxine ER.  There are areas of the country where very high doses of this medication are prescribed in excess of 350 mg per day - 225 mg per day is considered the FDA recommended max dose. Almost uniformly these patients improve with less venlafaxine and there is less confusion about medication side effects versus depression.

3. Chronic medication side effects:  

Some of the most serious long-term medication side effects include weight gain, metabolic changes including metabolic syndrome, diabetes mellitus, nephrogenic diabetes insipidus, hyperlipidemia, and movement disorders. In many cases the medications being used that lead to the side effects have been the only ones that will that work and even gradual changes may result in destabilization the patient. Some of these transitions between atypical antipsychotics or atypical antipsychotics and mood stabilizers result in a significant medication burden and risk for increasing side effects. It is critical that the transition is actually made to the new set medications.

Any medication side effect on a long term basis is obviously serious. Dry mouth one of the most common side effects can lead to dental caries and mouth soreness. Constipation is often considered a nuisance but it can lead to bowel obstruction and serious medical complications. Sexual side effects are a significant quality of life problem that can impact the most significant relationships in a persons life. Surveying for these side effects is a significant but necessary task for any psychiatrist.  

One of my very first experiences with chronic medication side effects was a patient who had been taking an old antidepressant - doxepin for about 5 years.  I started seeing him in that 5th year and he was no longer sure that he was depressed but he did notice he was chronically fatigued.  Because he had been on the medication for 5 years, I suggested that we taper him off of it.  He came back to see me and said he had not felt as well in a long time.  Not only had his fatigue resolved, but he no longer had chronic headaches.  In retrospect, he said he felt like he "had the flu" for the last 5 years. That experience led me to never suggest that people "get used to the medication" if they are having side effects.  I know that does happen in some cases, but I also know that most people just get used to feeling ill.

4. Rare but serious medication side effects: 

Looking at both neuroleptic malignant syndrome and serotonin syndrome, the literature frequently states that these acute life-threatening disorders occur around times of medication transitions. Trying to keep the load on both serotonergic and dopaminergic systems low during these transitions is one of my goals but I can’t really find any scientific literature to back it up. Literature out there tends to be case reports and that includes literature suggesting that medication transitions are associated with the acute disorders.

5. Interrupted medication transitions: 

I frequently see people who are on full doses of two and often three antidepressants. When I take their history there was a plan to add the new antidepressant and then taper and discontinue the old one but for some reason the old medication was not stopped.  This often happens in the outpatient setting and many times it is due to the patient not knowing that the old medication should be stopped or not getting a specific schedule to taper and discontinue it.

6. Polypharmacy: 

Polypharmacy can be highly problematic. It happens in just about every class of psychiatric medications. As an example, Adderall XR is designed to produce a concentration curve that is equivalent to Adderall immediate release dosed twice a day and yet I commonly see people taking Adderall XR either more than once a day or combined with an afternoon dose of Adderall immediate release. There are similar combinations of antidepressants, antipsychotics, mood stabilizers, and benzodiazepines. In a controlled setting where I practice I can make the necessary medication changes and follow-up the patient frequently. If that occurs in the outpatient setting there needs to be a plan in place for frequent follow-ups as well as active collaboration with the patient and the family.

7. Pharmacokinetic problems: 

The most common pharmacokinetic problem I encounter is people who abruptly stop Lamotrigine and resume the full dose.  Since lamotrigine began its psychiatric applications I have been in touch with the manufacturer many times and was advised that if the patient stops the medications for more than three or four days, the standard titration of lamotrigine needs to occur. It is fairly common for me to hear from people that they go off lamotrigine for a week or two and then resume the full 200 or 400 mg dose. I often see them after they have been on that resumed dose for one week.

The prototypical pharmacokinetic polypharmacy problem was SSRIs that were CYP2D6 inhibitors combined with tricyclic antidepressants (CYP2D6 substrates). The original reports of severe arrhythmias in some cases death from tricyclic antidepressant toxicity was the initial impetus for psychiatric interest in pharmacokinetics and drug interactions. I still see people today who are getting amitriptyline or nortriptyline in combination with fluoxetine or paroxetine and there has been no clear concern about those potential interactions.

8. New medical problems that impact prescription patterns:  

Acute renal and hepatic problems can directly impact the patient’s drug metabolism and dosing requirements or ability to take a specific drug.. One of the best examples I can think of is a case of 40 year old man who was taking gabapentin for anxiety and chronic pain. He was seen by an internist and started on a statin for dyslipidemia. Four days later when I saw the patient he was delirious and completely disoriented. He also had the significant ataxia and sedation. He was evaluated immediately and blood tests showed that he had acute renal failure that was believed to be secondary to the statin. The statin and the gabapentin were discontinued and within days he was back to his baseline.  If he had been on any other medications with primary renal clearance those would have been discontinued at same time.

9.  Correcting the medical side of things:

If the psychiatric medications are being taken incorrectly, there is a good chance  that the polypharmacy for heart disease, hypertension, diabetes mellitus, and asthma/COPD are also being taken incorrectly if they have been taken at all. It is problematic when a person has a disabling mental illness and they are left to take several doses of medication at different times of the day by themselves. When I started out in psychiatry, I could make a public health nursing referral at any time by sending in a form to the appropriate agency.  The next day, and RN would be at the patient's apartment setting up their medications, taking their blood pressure and pulse, and assisting them with managing their medications for the psychiatric disorder as well as all of their chronic medical problems.  That service ended with the rationing of all services to people with severe psychiatric disorders, making it much more likely that these medical conditions will not be as stable as they should be when they see their psychiatrists.  The is both a problem for the patient and the psychiatrist but also an opportunity to correct things.  

These are a few examples of the hierarchy of problems that occur with polypharmacy and in some cases standard pharmacy and how they can be approached. There apparently some groups out there at this time were trying to establish a hierarchy of how medications can be discontinued and when they should be discontinued. Like most cases in medicine in the extreme it is obvious but anything less than that is more difficult and it takes a lot of time to figure out. One thing that might be useful would be to consider drug combinations that are commonly prescribed as a baseline and look for polypharmacy being defined as anything beyond that.

One thing is for sure - the old rule about never prescribing two drugs from the same class - no longer applies.

George Dawson, MD, DFAPA

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.