Monday, October 31, 2022

Incident Atrial Fibrillation and Intoxicants



I remain very interested in the cardiac and brain complications of medications and substances that are commonly used to get high or create altered states.  I am also very interested in the popular trend to characterize cannabis as some previously undiscovered medication that can cure everything ranging from anxiety to obstructive sleep apnea.  I was naturally interested when I saw this paper (1) looking at the issue of incident atrial fibrillation and common intoxicants.

The authors examine a very large database in California that included anyone who had been seen in an emergency department, ambulatory surgery center, or hospital over a period of 10 years (2005-2015).  After they eliminate minors, subjects with persistent atrial fibrillation, and subjects with missing data they had a total of 23,561,884 people. 998,747 of those people had incident atrial fibrillation (defined as the first encounter for atrial fibrillation).  Since their study design is a retrospective observational study they also recorded substance use was considered present if Substance use was considered present if there was coding for any indication of use of methamphetamine, cocaine, opiates, or cannabis.  Knowing the atrial fibrillation and substance use diagnoses – the authors calculate the hazard ratio for each of the substances of interest.

Hazard ratios are basically the ratio of the people exposed to intoxicants who developed atrial fibrillation over the unexposed who developed atrial fibrillation.  So any number greater than 1 means that the population exposed to intoxicants had greater risk.  The corrected hazard ratios were noted to be 1.86 (methamphetamine), 1.74 (opioids), 1.61 (cocaine), and 1.35 cannabis. The authors adjusted for common atrial fibrillation risk factors and ran an additional negative control analysis and looked at the scatter of data pints for these 4 substances and hazard ratios of developing appendicitis, connective and soft tissue sarcoma, and renal cell carcinoma and showed no consistent pattern for these illnesses.

There are a couple of interesting considerations relevant to this study.  The first is the mechanism of action in each case. With stimulants there is a direct hyperadrenergic effects and depending on the individual and dose of the drug varying degrees of tachycardia, palpitations, and hypertension.  Long term users frequently end up with cardiomyopathy from these effects and in some cases ventricular arrhythmias and congestive heart failure. There can also be acute vascular effects like ischemia either due to the increased cardiac demand or pre-existing arteriosclerosis. Atrial fibrillation has not typically been placed in that group of morbidities from stimulant use. Patient with atrial fibrillation often notice emotional precipitants for discrete episodes or atrial fibrillation although a recent study showed that the only reliable precipitant was alcohol use (2). There were significant limitations with that study with attrition and length of the study although I generally agree that alcohol is a clear participant.  Precipitants need to be carefully approached and I suspect that attentive physicians have noted variable phenomenology on an individual basis. 

The high hazard ratio for opioids is a little puzzling. Hyperadrenergic states can occur with the euphorigenic effects and withdrawal effects as well. Direct comparison with stimulants may be difficult due to rapid dose escalation and some degree of tachyphylaxis.  Cannabis is not surprising to me at all. Many initial cannabis smokers notice that their heart is pounding and don’t know why.  They find it unexpected given the conventional wisdom that cannabis is supposed to be a benign substance. Many initial users also get increased anxiety and, in some cases, have a panic attack that may be due to the cardiac sensations. The primary heart pounding sensation is because cannabis causes hypotension and they are experiencing reflex tachycardia. The effects may be less predictable because cannabis use can affect both sympathetic and parasympathetic pathways that can potentiate arrhythmias. A case report of cannabis induced atrial flutter (3) was described as occurring in a woman with a history of hypertension that eventually had to be terminated by an intravenous antiarrhythmic.   

Atrial fibrillation and other cardiac arrhythmias are another good reason for avoiding intoxicants including alcohol (in the supplementary analysis alcohol had a Hazard Ratio of 2.37).  It could be argued that it is basically a numbers game – since most people who use these intoxicants do not develop incident atrial fibrillation.  As of this moment, even if you have had your DNA analyzed for what are known about atrial fibrillation genes – you can’t be certain that you are not susceptible to the problem. And as outlined above there are many additional cardiac problems and that are possible from using these compounds.  The safest path is to avoid these intoxicants all together.

 

George Dawson, MD, DFAPA

 

 

References:

1:  Lin AL, Nah G, Tang JJ, Vittinghoff E, Dewland TA, Marcus GM. Cannabis, cocaine, methamphetamine, and opiates increase the risk of incident atrial fibrillation. Eur Heart J. 2022 Oct 18:ehac558. doi: 10.1093/eurheartj/ehac558. Epub ahead of print. PMID: 36257330.

2: Marcus GM, Modrow MF, Schmid CH, Sigona K, Nah G, Yang J, Chu TC, Joyce S, Gettabecha S, Ogomori K, Yang V, Butcher X, Hills MT, McCall D, Sciarappa K, Sim I, Pletcher MJ, Olgin JE. Individualized Studies of Triggers of Paroxysmal Atrial Fibrillation: The I-STOP-AFib Randomized Clinical Trial. JAMA Cardiol. 2022 Feb 1;7(2):167-174. doi: 10.1001/jamacardio.2021.5010. PMID: 34775507; PMCID: PMC8591553.

3: Fisher BA, Ghuran A, Vadamalai V, Antonios TF. Cardiovascular complications induced by cannabis smoking: a case report and review of the literature. Emerg Med J. 2005 Sep;22(9):679-80. doi: 10.1136/emj.2004.014969. PMID: 16113206; PMCID: PMC1726916. [full text] 

Wednesday, October 19, 2022

Abstract Attack Journal Article Presentation Format

 

I recently participated in an Addiction Medicine Journal Club where the presenter used a novel presentation technique called Abstract Attack. The result in terms of group process was so good – I thought I would present it here for further exposure and comment.  As a qualifier I would add that I have not spoken directly to the creators and base this post on my direct participation in the format and the PowerPoint from the creators (1) and the presentation I attended (2).

Standard presentations in medicine and other academic fields typically consist of a single presenter charged with presenting data or techniques for information and some discussion.  The expertise of the presenter and role of the audience varies considerably.  For example, in my Biochemistry course in medical school the seminars were focused on techniques and concepts. The course instructor would typically choose a paper or two on a clear topic like diphtheria or cholera toxin.  The presenter was responsible for presenting those two papers at the minimum with additional papers as necessary. That was in 1978 – well before the Internet and online resources. All papers had to be obtained as hard copies from the medical library.  We would have two or three biochem seminars per week – so there were always a number of presentations to prepare for and the information content was variable.  My pharmacology course used a similar format but slide presentations were allowed. Since there was no digital presentation software – the slides had to all be shot on 35 mm film and projected.  That was the standard until well after I completed residency and started working. Eventually presentation software was developed making the job much easier.

Microsoft PowerPoint eventually evolved into the standard presentation format but it is not without controversy.  In the past 15 years there have been numerous presentations and papers written about everything that people consider to be wrong with PowerPoint.  That criticism is highly variable such as too little to too much information, being more boring that an extemporaneous lecture, problematic graphics and format on the slides, reading the slides, and competing software that claims to produce a better presentation.  The competition angle is an interesting one because in the beginning I bet on (and paid for) two competing products before it became apparent that PowerPoint would be the winner. It is difficult to win against a product that is installed on most business computers in the country.

My person bias is that I like the PowerPoint format.  The product is greatly improved in the past decade and can also be used to produce graphics for other applications.  I have attended seminars and courses on this to improve the approach with PowerPoint from a graphical standpoint and my slide making has improved considerably. I think it is very useful to put up graphics and texts that provide more information to the audience while I am free associating to the slides. To me the main difference between a verbal only lecture and a PowerPoint presentation is the greater informational content.  Consider that TED Talks are supposed to present a great idea in 18 minutes.  I am supposed to be presenting many ideas and facts in 50-50 minutes. That is what a PowerPoint presentation is for.

The doesn’t mean that all high information PowerPoints are successful. The speaker still has to be fairly good in both presentation style and engaging the audience. The audience has to be well behaved and focused on the content. I was giving a fairly detailed lecture on alcohol use and the latest World Health Organization (WHO) report on the scope of the problem.  There was a student in the audience checking the data on my slides (taken directly from the report) about what he could find on his phone and arguing about it. There are always unexplained emotional reactions in the crowd and in some cases, people get up and leave – even when nothing presented is really controversial. We have all attended presentations when the discussion starts with the dreaded: “I don’t have a question but I would like to comment……” followed by a 10 minute long irrelevant digression.  

When you experience all of those occurrences at conferences and lectures, you can’t help thinking: “Is there a better way to keep all of this on track?” Limiting the discussion, not taking questions, or having all of the questions submitted and moderated are certainly possibilities that I have seen used successfully. But I was recently exposed to a presentation format that structured the responses right in PowerPoint and that led to a focused high-quality discussion.  I will explain the format and hopefully provide a good example of how to approach the problem.

The method is called Abstract Attack and it was apparently devised by members of the University of Minnesota North Memorial Family Medicine Program.  Rene Crichlow, MD, FAAFP is credited with the concept and in the PowerPoint I acquired her co-presenters were Tanner Nissly, DO, and Jason Ricco, MD, MPH (1).  I first experienced this approach in a journal club teleconference (2) that was presented by Ian Latham, MD a resident from the UMN program on an article about lorazepam versus phenobarbital for alcohol detoxification based on a 2021 paper (3).

The overall goals for this presentation format are from family practice curriculum.  In the initial presentation the authors use the Accreditation Council for Graduate Medical Education (ACGME) requirements for scholarship to develop the Abstract Attack approach.  Those scholarship requirements can be found in the document on common requirements for all residency programs. Interested readers can find the specifics in a box graphic on page 26 of this document.  It is an elaboration of the way all physicians are trained to critique scientific and clinical studies and the application of the studies to clinical work.  The primary goals of Abstract Attack (1) are cited as:

1.  "Abstract Attack", a method to provide uniform acquisition of skills and knowledge

2.  Sufficient for a practicing clinician to confidently, participate in efficient and effective Evidence Based critique of the medical literature at the point of care

 The secondary goal is “Eschew Obfuscation”.

The overall process is described as patient rather than disease oriented and adhering to a critical appraisal pathway that answers the questions:   Pertinent to your patients’ care?  Consistent or Inconsistent?  Valid or Invalid?  The structured order of presentation is given in the slide below:


  

In the session I attended (2) the author discussed the overall goal of being able to present journal articles with the assumption that nobody else has read it.  He proceeded to illustrate how the presented information could be discussed at the level of every slide by the following prompts (that he incorporated in every slide):

What is interesting about this?

What is concerning about this?

What do I need to know more about?


I will illustrate with a few slides from a recent JAMA paper (5).  The slides cueing the discussion might look something like this.





   


Additional slides are provided on the methods and results.  That is followed by a slide with questions exploring how the study potentially impacts clinical practice and what additional information or studies may be needed.  Supplemental slides can contain information on the scientific and statistical concepts used in the paper.  The emphasis is clearly proceeding from the clinical trials to clinical practice.

My direct experience with this format is that there was timely discussion every step of the way.  Senior clinicians and physicians can add commentary early in the process about what they see are being important about the study.  The audience is clearly engaged without every reading the paper. The presenter can add critical information in supplementary slides at the end after the discussion on how impactful the information is on clinical practice and what else might be needed.

Overall, I thought this was a breakthrough in how to make these presentations efficiently when everyone’s time is at a premium. Dr. Crichlow and her colleagues are to be congratulated.  I have made a comparison slide below.



 

George Dawson, MD, DFAPA

 

References:

1:  Crichlow R, Nissly T, Ricco J.  Trans-formative Journal Club Experience as a Basis for a Longitudinal EBM Curriculum.  PowerPoint Presentation.  Accessed on October 16, 2022.

2:  Latham I. Phenobarbital Versus Lorazepam for Management of Alcohol Withdrawal Syndrome: A Retrospective Cohort Study Addiction Medicine Journal Club.  PowerPoint Presentation. August 2, 2022.

3:  Hawa F, Gilbert L, Gilbert B, Hereford V, Hawa A, Al Hillan A, Weiner M, Albright J, Scheidel C, Al-Sous O. Phenobarbital Versus Lorazepam for Management of Alcohol Withdrawal Syndrome: A Retrospective Cohort Study. Cureus. 2021 Feb 11;13(2):e13282. doi: 10.7759/cureus.13282. PMID: 33728215; PMCID: PMC7949711.

4:  Accreditation Council for Graduate Medical Education (ACGME).  Common Requirements Currently In Effect.  7/1/2022:  https://www.acgme.org/what-we-do/accreditation/common-program-requirements/  Accessed on 10/19/2022.

5:  Florian J, van der Schrier R, Gershuny V, Davis MC, Wang C, Han X, Burkhart K, Prentice K, Shah A, Racz R, Patel V, Matta M, Ismaiel OA, Weaver J, Boughner R, Ford K, Rouse R, Stone M, Sanabria C, Dahan A, Strauss DG. Effect of Paroxetine or Quetiapine Combined With Oxycodone vs Oxycodone Alone on Ventilation During Hypercapnia: A Randomized Clinical Trial. JAMA. 2022 Oct 11;328(14):1405-1414. doi: 10.1001/jama.2022.17735. PMID: 36219407.


Supplementary Info:

Any slide above can be enlarged by clicking on it.

 


Saturday, October 8, 2022

Minnesota Medical Cannabis Program Petitions

 



I have written about this program in the past.  In Minnesota, we have a medical cannabis program that allows for the prescription of specific forms of cannabis for a list of what are seen as indications.  To get on that list is basically a review of opinions and the Commissioner. Even though this program runs like a mini-FDA, it does not have a standard for approving conditions for medical cannabis use.  And let’s face it - that is because the supporting evidence for using medical cannabis is very weak and in many if not most instances – non-existent. And as I have pointed out in the past – the evidence collected by the program is also weak.  As far as I know the program does not produce any detailed adverse drug effect information and a lot of that advice depends on the pharmacists dispensing the medical cannabis.

This year the conditions up for placement on the list of indications include opioid use disorder, obsessive compulsive disorder, and irritable bowel syndrome. I restricted my comments to the first two conditions and the rationale is very clear. In the case of opioid use disorder (OUD), it is a widespread drug epidemic at this point fueled by widespread availability of opioids and synthetic opioids. Even though physician prescriptions have decreased overdose deaths continue to increase on a year-to-year basis. The pattern of overdoses has also changed substantially since OUD has spread from metropolitan to rural areas. Thirty years ago, OUD and overdose deaths were practically unheard of in rural areas and now they are commonplace. There are effective treatment for OUD as listed in the letter that follows.  There is a problem with access to substance use disorder treatment.  Most states have practically no detoxification facilities.  Access to physicians who are prescribing medication assisted treatment (MAT) for OUD (MOUD) is also very limited.

Like most political movements in the country – there is no critical analysis of the various cannabis initiatives.  To me – it was obvious from the start that medical cannabis was a way to start building political consensus for legalization of cannabis. Adding more intoxicants to the environment is never a good idea – but the practical issue is that the lesson of alcohol prohibition was that it could not be done without increasing crime, corruption, and the health dangers of unregulated alcohol. So a medical cannabis initiative is really not a genuine attempt to treat medical conditions with cannabis.

On that basis – it is not surprising that there is significant overreach in finding conditions where medical cannabis can be used. OUD and OCD are just two more diagnoses on that list. I was informed that my comments will be added but the vast majority of comments are not by physicians and are basically testimonials to cannabis. The FDA receives a lot of criticism and they also elicit public commentary but there is a core body of scientific decision makers.

With the writing of this post President Biden just came out with a statement that he is going to pardon people who are incarcerated for simple possession of marijuana and encourage governors to do the same (1).  That may be easier said than done since there was also a news report that the majority of these people have additional complicating charges.  He also initiated a review process by Secretary of Health and Human Services and the Attorney General on the way marijuana is listed in the Control Substance Act schedule.  It is currently a Schedule I drug making it the most dangerous and without medical applications according to this ranking. That results in a large grey zone when it is legally prescribed in some states and approved for recreation use in others.  There are associated problems with banking due to the federal scheduling but in an election year when any number of people from both parties are tripping over each other to legalize it – it seems like a foregone conclusion that it will be rescheduled at the minimum.

The Minnesota legislature approved low dose cannabis edibles earlier this year. There is a question about whether that was done by mistake. This is another step toward the eventual legalization of cannabis in Minnesota and will probably lead to the extinction of the Medical Cannabis program.  This story also illustrates the confusion among legislators about the basic differences between raw materials and cannabinoid derivatives. My viewpoint is legalization of cannabis was the goal all along and the users of medical cannabis have objected to higher fees for the medical product and many prefer smoking cannabis rather than using other forms.

 

George Dawson, MD, DFAPA

 

1:  Statement from President Biden on Marijuana Reform October 7, 2022 Link.

2:  Miranda S.  Minnesota lawmakers voted to legalize THC edibles. Some did it accidentally.  July 2, 2022 Link.


The letter not in support of indications for opioid use disorder or obsessive compulsive disorder:

October 3, 2022

Office of Medical Cannabis
PO Box 64882
St. Paul, MN 55164-0882

To Whom It May Concern:

I am a Minnesota psychiatrist who recently retired from clinical practice. I continue to research and write about psychiatry.  I worked at one of the largest substance use disorder treatment facilities in the United States. Every person I saw had a substance use disorder (SUD) that was significant enough to need residential treatment. Alcohol use disorder was the most common followed by opioid use disorder (OUD).  I was also an adjunct professor and lectured on the epidemiology, assessment, and treatment of substance use disorders. Areas of focus included the neurobiology of SUD, opioid use disorders, chronic pain, and Attention Deficit~Hyperactivity Disorder. I did research on medication assisted treatment of alcohol use disorder and depression. 

As an SUD develops, there are several associated biases that lead to chronicity. The first is the euphorigenic effect or “high” that occurs with all substances. That becomes a permanent memory that all subsequent episodes of use are compared against. Tolerance to drug effects limits the ability to experience that same degree of euphoria.  That leads to attempts to use more or more powerful versions of the same drug. In the case of OUD, that has led to the use of more powerful opioids like fentanyl. A second bias is the idea that all emotions and reactions to stress can be controlled by external substances.  Cannabis, alcohol, and benzodiazepines are used for that purpose. In that situation, withdrawal symptoms are misinterpreted as anxiety or depression.   That leads to an additional substance being taken. Detoxification is required to determine a person’s baseline state and whether there is a treatable anxiety or depressive disorder. A third bias is that “I have a lot of time to quit.” Young people with severe SUD will often tell themselves: “I am only in my 20s, I can quit later and at that time go to work or school.” That prolongs their risk exposure and the associated morbidity and mortality. A fourth bias is people with SUD are not risk averse. In other words, if they knew a substance contained fentanyl and were risk averse, they would avoid it. This is not true. Many will seek out fentanyl products or products they know contain fentanyl in pursuit of getting high. That pursuit can get to the point that greater amounts of substances or more novel substances are used and they do not care what the outcome is. They are willing to risk a fatal outcome in pursuit of getting high.  Finally, withdrawal symptoms from substances create a negative reinforcement bias – substances need to be taken to avoid withdrawal symptoms.

Easy access to opioids is a major factor in the continuing opioid crisis and the “three waves” of this epidemic that are described by the CDC (1). There were several papers (3) published that suggested that medical cannabis use was associated with less opioid use. Those findings have not been validated over time.   There has been a study done showing that opioid use was more likely to increase rather than decrease (4) with cannabis use. That study is consistent with what I have seen in the clinic.  

To summarize:

1.  We are still in the midst of a 2 decades long opioid use epidemic that has produced significant overdose mortality and morbidity. 

2.  There are current FDA approved treatments (10 drugs in 3 categories) that have demonstrated ability to prevent opioid overdoses and treat opioid use disorder (2). 

3.  Suggesting that Minnesota residents with an opioid use disorder use cannabis with no proven treatment efficacy over the FDA approved medications that have efficacy presents a clear ethical problem considering the level of mortality associated with this disorder.

For these reasons medical cannabis should not be approved for opioid use disorder.

I am also recommending that medical cannabis not be approved for the treatment of obsessive-compulsive disorder. The bulk of my argument rests on the information that I submitted last year recommending no medical cannabis approval for generalized anxiety disorder. In that submission, I pointed out that for many people cannabis use leads to anxiety and panic attacks rather than alleviating them. Obsessive-compulsive disorder (OCD) has effective psychotherapies and medical therapies. In fact, psychotherapy is the primary treatment modality. We currently have a healthcare system that rations access to both psychotherapy and medical treatment. When the lack of clinical trials of cannabis in OCD is considered, the same ethical dilemma presents as in the case of opioid use disorder. Is cannabis approved for OCD because health care systems and government regulators refuse to provide access to proven methods of treatment?

In both the case of opioid use disorder and obsessive-compulsive disorder, neither should be an indication for medical cannabis for the above stated reasons.

Sincerely,

George Dawson, MD, DFAPA

Lino Lakes, MN

 

 

References:

1:  CDC.  Understanding the Epidemic:

https://www.cdc.gov/opioids/basics/epidemic.html

 

2:  FDA Information about Medication-Assisted Treatment (MAT):  https://www.fda.gov/drugs/information-drug-class/information-about-medication-assisted-treatment-mat

3. Bachhuber MA, Saloner B, Cunningham CO, et al. Medical cannabis laws and opioid analgesic overdose mortality in the United States, 1999–2010. JAMA Intern Med. 2014;174:1668–1673.

4:  Olfson M, Wall MM, Liu SM, Blanco C. Cannabis Use and Risk of Prescription Opioid Use Disorder in the United States. Am J Psychiatry. 2018 Jan 1;175(1):47-53. doi: 10.1176/appi.ajp.2017.17040413. Epub 2017 Sep 26.

 


Thursday, September 29, 2022

Emotional Blunting By Antidepressants - Does It Occur?

 


Ron Pies and I reviewed three recent papers on emotional blunting in this paper called Antidepressants Do Not Work by Numbing Emotions. It is a very self-explanatory essay that I encourage anyone to read if they have an interest in that topic specifically or in the general repetitive criticism that only our field seems to enjoy. I have previously commented on the rhetorical aspects to a previous paper and recent publications allow us to address specific scientific issues. The main argument that emotional blunting is the mechanism by which antidepressants work - has no scientific merit as explained in the essay. The basic argument is that if emotional blunting is rated at baseline before any antidepressants are started it is present and as treatment begins and starts to work – emotional blunting decreases as the depression remits. That led the authors we reviewed to conclude it was more likely a symptom of depression than either a mechanism of action or a side effect.

 1:  Measurement – is a better measurement needed?

In the reviewed studies we made some specific comments on the methodologies used to detect emotional blunting specifically Item 8 of the Montgomery Ã…sberg Depression Rating Scale (MADRS) or the Oxford Depression Questionnaire (ODQ). The ODQ was previously the Oxford Questionnaire on the Emotional Side-effects of Antidepressants (OQESA or OQuESA).

The single item on the MADRS provides the most unbiased assessment of emotional blunting and is a single question worded very much like a clinician might ask to assess the problem. The ODQ has more questions and a specific question where the subject is asked to estimate whether or not the antidepressant is contributing to antidepressant side effects.  Since no other potential etiologies (like depression) were considered we thought that these were questions that might lead to predictable biases like choosing antidepressants as the cause of decreased emotional range rather than the depression.

Are there better questionnaire designs to eliminate bias and allow for quantification.  Two good examples include the Attributional Style Questionnaire (ASQ) (1) and the Cognitive Style Questionnaire (CSQ) (2). In both of these questionnaires - subjects are asked in an open format to write down what they consider to be the cause of a hypothetical situation, answer a question about that situation, and then rate the important of the cause. The questions are all focused on perceived internal and external causes of depression consistent with the cognitive theory of depression. There is no reason why a similar questionnaire could not be designed to find cognitive and emotional side effects of medications.  It could be validated by including questions about the known physical side effects of medication.    

2:  Normal subjects taking antidepressants:

In thinking about unbiased opinions about the emotional effects of antidepressants my mind wandered back to a paper I read in the American Journal of Psychiatry many years ago.  It was easy to remember because it involved giving fluoxetine to research subjects who had no known psychiatric diagnoses. In that study – 15 subjects were enrolled and took placebo for two weeks followed by fluoxetine 10 mg x 1 week then fluoxetine 20 mg/day x 5 weeks and then placebo daily for two weeks.  There were assessed weekly on standard scales for anxiety and depression.  They were also assessed weekly on the General Well Being Schedule and the Quality of Life Enjoyment and Satisfaction Questionnaire.  Subjects were also assessed weekly for side effects and only three of the 15 subjects reported side effects and they were nausea, dyspepsia, and dizziness – all typical SSRI side effects.  The authors conclude:

“No significant effects attributable to fluoxetine were observed on any of the psychological variables examined. Minimal adverse effects were reported. … Significant mood elevating and other psychological effects of fluoxetine would appear to be induced only when symptomatic targets exist.”

Interestingly these authors contrast their work with that of Peter Kramer (4) and suggest that: “….mood-enhancing and other psychoactive effects of SSRIs are not a general property of these agents but are manifest in the context of target symptoms.”  A similar argument has been made about emotional blunting and why it may not occur in normal subjects.

In a second study of fluoxetine and dothiepin in subjects without mental illness a 5 week placebo controlled, double blind crossover study was used (4).  Each subject received each treatment and placebo.  The active treatment lasted for 35 days. Subjects received fluoxetine 20 mg/day or dothiepin (a tricyclic antidepressant) titrated to 150 mg/day. They were tested at day 10 and day 36.  Eleven mood ratings using an analogue scale were done three times a day. The subjects were also asked is they had any “problems with your health”.  Some increased irritability (3 subjects), anxiety (one subject), and “mood lowering” (2 subjects) was noted.  There were no reports of emotional blunting. The researchers generally reported:

“Throughout the study period, all subjects remained well, including during the drug-free periods between treatments.”

In looking for a third study, I found one by David Healy – a well-known pharmaceutical business critic (6).  This study involved 20 subjects randomized to receive 2 weeks of either reboxetine or sertraline in a cross over design.  There was an option to increase either drug to the next expected level on day 5 of active drug treatment.  Three scales were done on a daily basis including the Profile Of Mood States (POMS), Positive and Negative Affect Scale (PANAS), and the Social Adaptation Self Evaluation Scale (SASS).  A side effects questionnaire was administered. Subjects were also asked if they could distinguish the “behavioral effects” of the drugs and to rate their preferences on an 11 point Likert scale ranging from “worse than normal (-5) to better than normal (+5).  A relevant excerpt from this paper:

“In focus group settings, while still under the blind, half of the subjects volunteered that sertraline made them mellow, or less emotionally reactive and that these effects were either appreciated or not, while yet others described agitation. Effects consistent with a reduction in emotional reactivity were not described with reboxetine.”

This focus group observation was not observed in any of the data collected from the mood rating scales.  The authors point out studies suggesting that normal volunteers do not tolerate medications well and suggest that their study shows that tolerance of the antidepressant may depend on whether it is a preferred agent of the subject.  Side effects listed but not quantitated include chilblains, sweats, insomnia, nausea, sexual dysfunction, and “jaw or throat dyskinesias or dystonias on sertraline.”

In summary, my main additional concerns about the emotional blunting issue and whether it occurs to any extent with antidepressants is one of accuracy of measurement and why it has been conspicuously absent in clinical trials until recently – including trials where antidepressants are given to normal controls (defined as volunteers screened for the presence of any current or lifetime psychiatric disorders).  Although I suggested a way to get to a much less biased measurement of emotional blunting, I have a question about whether it can be accurately measured at all in an era where psychiatric research is often presented as political debate in social media and the popular press. There have been many examples of how biased press coverage has misrepresented the effects of psychiatric medications and you only have to look as far as the Peter Kramer reference and the appendix on “Violence”.  A study to look at a better questionnaire to see if this is ever spontaneously mentioned when it is not cued would be useful - but it is probably not any more possible today than asking if the last election was stolen. 

On the issue of emotional blunting in clinical practice – I have seen the equivalent in some patients over the years. I typically discuss it with people as restricted affective range that either they notice or other people notice. It typically occurs during reassessments of people who have partially remitted depressions. At that point in time, it makes sense to discuss the time course of that phenomenon and try to determine the time course and whether it is improving or getting worse. After making it explicit at that point – the options in clinical care include continued observation or an immediate change to a different medication. That aspect of clinical care would be an interesting study in itself – because in my experience the majority of people do not want to change the medication at that initial discussion. I think it is also an element of ongoing informed consent at that point.

At a practical level, I think that the study by Peters, Balbuena, and Lodhi (7) that we referenced has paved the way for many more replication studies for any RCTs of antidepressants that used the Montgomery-Ã…sberg Depression Rating Scale (MADRS) and that is a very significant number.

It also requires a degree of biological sophistication to realize that brain systems are so complex and individualized that you cannot expect a medication to affect everyone in the exact same way – either positively or negatively. In fact, you cannot have that expectation in attempting to treat far less complex organ systems. Responses to treatment and side effects in medicine are always probability statements.


George Dawson, MD, DFAPA

 

References:

1. Peterson C, Semmel A, Von Baeyer C, Abramson LY, Metalsky GI, Seligman ME. The attributional style questionnaire. Cognitive therapy and research. 1982 Sep;6(3):287-99.

2.  Haeffel GJ, Gibb BE, Metalsky GI, Alloy LB, Abramson LY, Hankin BL, Joiner Jr TE, Swendsen JD. Measuring cognitive vulnerability to depression: Development and validation of the cognitive style questionnaire. Clinical Psychology Review. 2008 Jun 1;28(5):824-36

3.  Gelfin Y, Gorfine M, Lerer B. Effect of clinical doses of fluoxetine on psychological variables in healthy volunteers. Am J Psychiatry. 1998 Feb;155(2):290-2. doi: 10.1176/ajp.155.2.290. PMID: 9464215.

4. Kramer PD: Listening to Prozac. New York, Penguin, 1993

5.  Wilson SJ, Bailey JE, Alford C, Weinstein A, Nutt DJ. Effects of 5 weeks of administration of fluoxetine and dothiepin in normal volunteers on sleep, daytime sedation, psychomotor performance and mood. J Psychopharmacol. 2002 Dec;16(4):321-31. doi: 10.1177/026988110201600406. PMID: 12503831.

6.  Tranter R, Healy H, Cattell D, Healy D. Functional effects of agents differentially selective to noradrenergic or serotonergic systems. Psychol Med. 2002 Apr;32(3):517-24. doi: 10.1017/s0033291701005086. PMID: 11989996.

7.  Peters EM, Balbuena L, Lodhi RJ. Emotional blunting with bupropion and serotonin reuptake inhibitors in three randomized controlled trials for acute major depressive disorder. J Affect Disord. 2022 Dec 1;318:29-32. doi: 10.1016/j.jad.2022.08.066. Epub 2022 Aug 24. PMID: 36029876.

8.  Hieronymus F, Lisinski A, Østergaard SD, Eriksson E. The response pattern to SSRIs as assessed by the Montgomery-Ã…sberg Depression Rating Scale: a patient-level meta-analysis. World Psychiatry. 2022 Oct;21(3):472-473. doi: 10.1002/wps.21029. PMID: 36073711; PMCID: PMC9453909.


Supplementary:

I was made aware of a new analysis of MADRS data (8) today after writing the above essay.  Those authors analyzed MADRS ratings from 4,243 subjects participating in twelve acute phase placebo‐controlled trials of an SSRI in major depression and looked at emotional blunting on Item 8 of the scale. They found that treatment reduced emotional blunting with the same effect size as other items on the scale.  They agree with the opinion that emotional blunting should not be ignored but in the case of these antidepressant trials the ratings moved in a favorable direction.

Updated Table including this new analysis (click to see a clearer version):



Graphic Credit:

Nasa surface of Europa per their media guidelines


Saturday, September 24, 2022

Old Men Throwing a Football…

 


Three days ago – I drove up to my hometown on Lake Superior to visit relatives and some friends that I have had since childhood.  From about 1963 to 1973 we played football primarily but also several other sports in and around the only park we had as kids.  For a few months in the winter, it was a skating rink.  The rest of the time it was an abandoned field.  For about half of those years, the field was next to a ravine with a small swamp at the bottom of it.  Eventually the ravine was filled in and it was an even rougher field to play one.  We stuck to the rink surface, an abandoned lot across the street and in the wintertime the streets lined by snowbanks.  Of course, in the fall and winter we typically played in the dark after school.

And we played every night – in the rain, snow, and subzero weather.  There was no formal start time. Sometimes I would hear a pebble bouncing off my bedroom window and look out and the boys were all there waiting.  Other times I would step out into the alley and two blocks away see one of my friends waving his arms in a crossing motion over his head.  I would reply with the same motion, and we would head to the field. People would filter in when they saw us there warming up.  Quitting time, was highly dependent on when the neighborhood store closed (usually 8:30 PM).  The winner was often determined by that quitting time: “Whoever gets to this score or 8:15 PM”.  Our post game ritual was consuming 16 oz RC Colas at the store, and we couldn’t miss it.  

Most of these games were 2 on 2 or 2 on 3 passing games.  As a result we could all throw well and learned to catch a football very well. What was remembered three days ago was learning how to catch a ball that disappeared above the streetlights in the extreme dark cold of winter when it suddenly reappeared under the lights.  We would say “it came out of nowhere” – but we would catch it. On this day we did not do any kicking or punting, but I also remembered the guy in our group who taught himself to punt a perfect spiral.  It was amazing to see and that disappeared above the streetlights for a very long time before it came into view.

Today we were focused on short passes of 10-30 yards and throwing flat minimal arc spirals. I still recall my high school coach showing us how to throw a spiral with the nose of the ball slightly elevated for more distance and that was what I was going for.  I wondered if we were going to throw for distance like we used to do but that never happened.  The focus was on these short passes and catching the ball in the hands.  The fall detection on my watch was set off by catching a few of these passes. These passes still had a little heat on them. One of my friends talked about having "$1,000 hands" based on what he caught at work and telling the story of how he developed that ability. 

Only a couple of us played organized sports.  I wrote about that in another post. But the caliber of play was high.  Playing a sport every day for 10 years brings with it a high degree of athleticism both in terms of conditioning and coordination.  And it seems hard to believe these days but the only diversions available to us was very mediocre black and white television transmitted through the air and reading. Technical problems were common with the TV and to see a show you had to be there. It seems hard to believe now - but there was no on-demand viewing or recording.  Reading was limited by what you could buy or borrow from the library. At the same store where we drank the RC Colas – a bookmobile showed up every Saturday.  I remember borrowing and reading When Worlds Collide - a novel written in 1933 - and being fascinated by it.  Toward the end of my football period I worked for the library and mailed books out to other bookmobile locations.

That lack of diversions – technical and otherwise may have kept us focused on our game.  Several people commented to me that nobody ever plays in that field anymore.  On some days we had 10 or 20 additional players.  But these days nobody ever shows up and plays every day.  The city baseball and softball leagues have also been decimated far beyond what could be accounted for by a population decrease. It seems that in small town America not many people are playing sports anymore.

As we were throwing the ball around. One of my friends reminded me of a time when I threw him a pass and he dropped the ball.  I told him to take his gloves off so he could catch it the next time and it was 17 degrees below zero at the time. I am certainly not the same guy I was back then – you become a better person with age.  I asked him what he made of that today and he summed it up: “That’s just the way it was back then.”  There were definite periods where we were unnecessarily rough and angry. But I don’t recall any out and out fights.  The roughness of the game when you are a kid is a source of pride.  We were all from the East End and we had a shared "wrong side of the tracks" blue collar mentality. To this day – one of my friends in the photo gives West Enders a rough time.  He told me that he recently asked one of them: “Did you even play outside when you were kids?”  Trash talking is not a new invention.

The shared experience is something I never thought about at the time. I heard a recent piece on This American Life about the importance of camping to some people and how there were campers and non-campers and the non-campers would never understand the emotional importance of camping.  The same thing was true of our football games.  It gave us all meaning at a time in our lives where there wasn’t much. It gave us a chance for intense emotional expression and eventually being able to control that expression.  It helped us through some pretty bad times. I still remember hearing the pebble bounce off my window and telling the guys: “I can’t play today – my Dad died last night.”  I remember the expression on their faces when they heard that news. I remember it as clearly as if it happened yesterday.  All of the homilies that I heard at various sports banquets about the importance of teamwork - rings hollow. It is more important just to be there and share the experience.  Nobody ever tells you that when you are a kid beating yourself up for losing a game. It really doesn't matter who wins or loses.  It doesn't matter how you play either. It just matters that you show up and keep showing up.

This day - it was happier times.  We had all just finished working - as in retired.  School, work, and in some cases military service were all necessary distractions from our game. One of my friends has just completed 41 years of work without missing a day and for some of those days he was working 7 days a week. We had all dodged severe medical problems of one form or another.  We had all survived COVID so far and had the vaccinations. It was a good day to be alive on our childhood playing field.   

We may have lost a step or two but old men can still throw and throw quite well.  But there were no diving catches.

 

George Dawson, MD, DFAPA

Wednesday, August 31, 2022

Happy Labor Day

 


Happy Labor Day

 

“It should be evident to all students, residents, and practicing physicians that the enormous investment in time, money, and commitment typically necessary to become a physician makes no sense if practicing medicine frequently fails to be interesting and enjoyable.”  Samuel B. Guze, MD 1992 (1)

 

Every year I try to post something about my impression of the physician work environment. That has been a progression of depressing posts as the work environment deteriorates every year largely due to micromanagement by managed care companies and various governments that has resulted in a trillion dollar overhead, quality as an advertising meme rather than a clinical reality, poorer reimbursement for physicians, massive numbers of wasted hours for the bureaucracy and its documentation requirements, and the negative feedback loop of using the healthcare system as a jobs program for business administrators.  Each of those iterations moves use farther and farther from Dr. Guze’s reality of an enjoyable and intellectually stimulating career in medicine.  Interestingly – enjoyability is not an obvious factor in the most frequently used scale to detect burnout in medical staff.  Those scales tend to be focused on a learned helplessness/loss of personal efficacy model.  Lack or loss of enjoyability is probably the first step toward that extreme conclusion.

It is equally frustrating for patients who have seen access get markedly worse.  Just this month I tried to assist a friend in finding a therapist either inside or outside of her insurance plan. And there were none. I am not talking about a waiting list and an appointment 2 or 3 months out.  I am talking about no access at all.  The clinics would not even place her on a waiting list.  I saw a consultant myself back in January who told me he was referring me to another specialist to be seen this August.  When that did not happen, I called and my calls were not returned. Eventually by sending enough messages to my primary care MD they called me and set up an appointment on September 2.  I was called yesterday and told that appointment was cancelled.  They gave me another appointment in mid-November with the qualifier: “We have you penciled in but there is no guarantee that this won’t change again”.

I am very aware of the strain the pandemic and its mismanagement has put on the system.  Also aware of physicians and nurses resigning in droves (2). In the case of primary care specialties and psychiatry there was a serious shortage before the pandemic hit.  The pandemic itself is an insufficient explanation for what has happened over the past three years. The lack of an adequate pre-existing public health infrastructure had a lot to do with it (4).  Inadequate protection for front line workers and an inability to scale as the morbidity and mortality increased in some cases exponentially. In the case where public health officials were doing what they could they often found themselves threatened and attacked by pandemic deniers, anti-vaxxers, and let’s face it various elements of the right wing (3). The same people basically responsible for building out America’s immense for-profit and inefficient health care system. What could be more depressing than to try to treat a pandemic while a political party is basically denigrating standard public health measures and either verbally attacking or threatening public health officials to the point that many had to get security personnel for protection. When you have a big enough platform – I consider acts of omission-like not taking a stand firmly against political violence as bad as the people making the threats. I also don’t make any distinction between threats from the average man or woman on the street and members of Congress making clear threats.  Many seem to act like they have immunity in those situations.

The politically designed medical systems of care that is basically run by unqualified business people was ramped up to even worse performance by the associated political anarchy. That anarchy continues. Who could blame physicians for bailing out in those circumstances?  I think there is a legitimate concern about whether the system will every get back to its baseline prepandemic inefficiency.

Some have considered the increased use of telemedicine and telepsychiatry to be a positive correlate of the pandemic. I gave a continuing medical education presentation on it in November of 2021. For various reasons – I think the eventual outcome of telemedicine is uncertain. The main reasons have to do with businesses taking over and managing the visits for profit and to the detriment of any therapists or physicians involved. A review of what can happen was published in the New York magazine (5). I see television ads all the time for rapid access to all kinds of prescriptions just by calling a business running a specialty telemedicine site. Some of these sites are already controversial and there appears to be very little transparency when it comes to comparing these sites to the even meager quality of care offered by in-person managed care.  Payer gaming at all levels is another possibility. During the pandemic reimbursement for care delivered was at the standard rate.  We are just starting to see decreased reimbursement or no reimbursement for televisits. I have also seen very disadvantageous contracts for physicians and therapists attempting to do televisit work at the levels of reimbursement, risk, and required access. That is consistent with the decade’s old observation that medical practice environments deteriorate in quality with increasing business involvement.

On a positive note this year – the main alternative to maintenance of certification by  American Board of Medical Specialties (ABMS) is the National Board of Physicians and Surgeons (NBPAS). This year the NBPAS was given recertification status by the Joint Commission and hospital accrediting agencies. The NBPAS model is the original “life long learning” model proposed for all physicians since the Flexner era. I have personally been recertified every two years by the NBPAS, but until this year realized that most younger physicians were not in a position where they could abandon much more costly and some would say overly involved ABMS recertification procedures.  The change this year apparently makes it easier to make that transition, but a lot will depend on hospital committees and local accreditation procedures. ABMS recertification is onerous enough to tip the balance in favor of leaving the field for retirement of a different occupation so that this change may also lead to physician retention.  But a lot will depend on how all of this unfolds.

I can still recall reading about why Paul Tierstein, MD came up with the original idea for NBPAS. He noticed a colleague who was an electrophysiologist cramming for a recertification examination and learning details he would never use in his day-to day practice.  Most physicians – even within their own specialty or subspecialty develop a knowledge base for that practice.  That knowledge base is not consistent with a preparatory based knowledge learned in medical school or as a resident. Relearning irrelevant material for the sake of taking an examination is another unnecessary drain on a physician’s time and finances. Life long learning is a better way to acknowledge that physician’s highest level of certification and ongoing efforts to maintain that specialized knowledge.

All things considered it has been another very stressful year for physicians. There is a glimmer of hope on the recertification front that will hopefully alleviate a lot of unnecessary stress.      

We still have a very long way to go to reach Dr. Guze’s suggested practice environment that is both fun and intellectually stimulating.  Like he says in his book – I was taught about that is medical school and experienced it only in the very first years of practice. We need to make medicine interesting and enjoyable again and that’s a very tall order.

 

George Dawson, MD, DFAPA


Supplementary:

 Explanation of the graphic: sometime ago I posted that heavy lifting is a metaphor for what has happened to medical practice in the US. This is another example. 

References:

1:  Guze SB. Why Psychiatry Is a Branch of Medicine. New York; Oxford University Press: 1992: p. 118.

2:  Abbasi J. Pushed to Their Limits, 1 in 5 Physicians Intends to Leave Practice. JAMA. 2022;327(15):1435–1437. doi:10.1001/jama.2022.5074

3:  Ward JA, Stone EM, Mui P, and Resnick B, 2022:Pandemic-Related Workplace Violence and Its Impact on Public Health Officials, March 2020‒January 2021.American Journal of Public Health 112, 736_746, https://doi.org/10.2105/AJPH.2021.306649

4Bishai DM, Resnick B, Lamba S, Cardona C, Leider JP, McCullough JM, Gemmill A. . Being Accountable for Capability—Getting Public Health Reform Right This Time. American Journal of Public Health 0, e1_e5, https://doi.org/10.2105/AJPH.2022.306975

5: Fischer M.  The Lunacy of Text Based Therapy (And other technological solutions for a nation in trauma).  New York Magazine March 29-April 11, 2021.

Image Credit:

National Archives and Records Administration, Public domain, via Wikimedia Commons https://commons.wikimedia.org/wiki/File:Girls_deliver_ice._Heavy_work_that_formerly_belonged_to_men_only_is_being_done_by_girls.

Heavy work that formerly belonged to men only is being done by girls. The ice girls are delivering ice on a route and their work requires brawn as well as the patriotic ambition to help. - NARA - 533758. https://upload.wikimedia.org/wikipedia/commons/0/0a/Girls_deliver_ice._Heavy_work_that_formerly_belonged_to_men_only_is_being_done_by_girls._The_ice_girls_are_delivering_ice_on_a_route_and_their_work_requires_brawn_as_well_as_the_partriotic_ambition_to_help._-_NARA_-_533758.gif

Friday, August 19, 2022

Has The Mechanism of General Anesthesia Finally Been Discovered?

 


General anesthesia is one of the greatest innovations of modern medicine.  Even within  the history of that innovation there have been tremendous improvements ranging from the administration of ether in the 1960s to very closely monitored combinations of opioids, benzodiazepines, and inhaled anesthetics in more modern times. The mechanism of action of opioids and benzodiazepines at the receptor level are known, but the effects of inhaled anesthetics have been more of a source of speculation.  I first became aware of this as an undergraduate taking physical chemistry (1) when I read about Linus Pauling’s hypothesis (2).  He suggested that microcrystalline hydrates form from the reaction of anesthetic gases and water molecules at the membrane surface. Those microcrystalline hydrates then interfere with synaptic transmission leading to loss of consciousness. Pauling was a physical chemist who was awarded the Nobel Prize for his work on the hydrogen bond and wrote about many general anesthetics as not working through hydrogen bond mechanisms.  He was also very optimistic about the role of physical chemistry in biological systems. Interestingly he briefly discusses how general anesthesia and the mechanism are important for psychobiology (2):

“The progress that has been made in the field of molecular biology during this period has related in the main to somatic and genetic aspects of physiology, rather than to psychic. We may now have reached the time when a successful molecular attack on psychobiology, including the nature of encephalonic mechanisms, consciousness, memory, narcosis, sedation, and similar phenomena, can be initiated. As one of the steps in this attack I have formulated a rather detailed theory of general anesthesia, which is described in the following paragraphs.” (p. 15)

He provides an elaborate physical chemistry rationale for the hydrate-microcrystal theory of anesthesia in this paper.  Pauling’s work comes on the cusp of the era of molecular biology – a field that he is credited with creating.  In his original explanation he discussed x-ray crystallography of crystals and new biologically active protein structures continue to undergo this analysis when they are isolated and purified.

Fast forward to a paper I just read in Current Biology a few days ago (3). It is written in the context of no clear mechanism of action for volatile inhaled anesthetics since their first observed effects noted over a century ago despite numbers speculative papers including papers from the past decade in this same journal.  The authors suggest that a disruption in electron transport in the mitochondria specifically Complex I  of 4 transport proteins is the area responsible for the effects of general anesthesia. Before getting to their experiment, a few words about this system.

Electron transport, oxidative phosphorylation, and ATP synthesis are all tightly coupled processes occurring over 5 proteins known as mitochondrial complexes (Complexes I-V).  Before the era of molecular and structural biology, these processes were partially deduced using in vitro methods looking at chemical reactions in mitochondrial preparations and specific reactions that affect each step. The cofactors were determined along with the overall stoichiometry of the process. With greater emphasis on structural and molecular biology there have been additional hypotheses about the specifics of electron transfer across the complexes and how ATP synthesis occurs.  Although there is much evidence to support various hypotheses about how all of these processes occur – in all of my reading it does not appear to be settled science.  In fact, some authors talk about emergent properties of this system that cannot be defined by what is known about the current components (10).  The discussion of emergent properties is interesting on at least a couple of levels. First, that kind of discussion is routine in consciousness research. There are no clear-cut biological mechanisms that generate a conscious state and it is discussed as an emergent property of the brain. Second, the minimum requirements of a biological system to create emergent properties is never really discussed. Does the mitochondrial system of electron transport, generating a proton gradient, ATP synthesis, and tightly couple oxidation and phosphorylation qualify?

This mechanism may have implications for the science of consciousness. In humans who are in good health and have no known brain diseases - general anesthesia and non-REM (NREM) sleep are considered to the the only states of unconsciousness. During that time the thalamus appears to be inactivated (13).  There have been several studies showing that some people dream during NREM sleep so that is not a clear boundary. But in the case of this mechanism questions would include considering the synaptic mechanisms as well as the global neuroanatomical mechanisms as well as the issue of emerging properties of biological systems of varying complexity.  What does it mean if a smaller system with emergent properties can turn off a larger system with emergent properties? What is the relationship of the emergent properties between systems?  

Moving on to the paper – the authors start by pointing out that neurotransmitter recycling in neurons is dependent on ATP and endocytosis.
  Further - that Complex I of the mitochondrial electron transport chain (ETC) is the rate limiting step in this process and that disrupting it causes sensitivity to volatile anesthetics (VA). Knockout mice (for a protein in Complex I) were physiologically normal but much more sensitive to VA. The authors hypothesized that VAs decrease presynaptic ATP production by the ETC (oxidative phosphorylation) leading to decreased endocytosis and neurotransmitter cycling, and that the inhibition of Complex I was the primary mechanism.  They conduct a number of experiments to illustrate the effects of VA (isoflurane) on the ETC chain looking at perturbations would increase the effect and decrease the effect and conclude that their hypotheses are supported by the data.  They conclude that Complex I inhibition may be the mechanism of action of isoflurane. If supported by other studies the mystery of the mechanism of action of VA may be solved after 170 years.

I continue to be astonished at the trajectory of brain science and all of the factors that are needed for these advancements.  Even at the level in this paper the suggestion is that the proposed hypothesis will require additional work.  This research occurs at the intersection of a series of historical hypotheses about the mitochondrial ETC and parallel hypotheses about the mechanism of action of volatile anesthetic gases. The scientific work and hypothesizing was built both on previous discovery and advances in technology.  In this area advancement was slow and is still not completely settled in either research area. A lot of science discussed in the press seems to suggest that there are arbitrary time frames or amounts of investment for advances and that is obviously not true.

George Dawson, MD, DFAPA

 

References:

1:  Moore WJ.  Physical Chemistry, Fourth Edition. Englewood Cliffs: Prentice-Hall, Inc; 1972: p. 241-243.

2:  Pauling L. A molecular theory of general anesthesia. Science. 1961 Jul 7;134(3471):15-21. doi: 10.1126/science.134.3471.15. PMID: 13733483.

3:  Jung S, Zimin PI, Woods CB, Kayser EB, Haddad D, Reczek CR, Nakamura K, Ramirez JM, Sedensky MM, Morgan PG. Isoflurane inhibition of endocytosis is an anesthetic mechanism of action. Curr Biol. 2022 Jul 25;32(14):3016-3032.e3. doi: 10.1016/j.cub.2022.05.037. Epub 2022 Jun 9. PMID: 35688155; PMCID: PMC9329204.

4:  Sharma LK, Lu J, Bai Y. Mitochondrial respiratory complex I: structure, function and implication in human diseases. Curr Med Chem. 2009;16(10):1266-77. doi: 10.2174/092986709787846578. PMID: 19355884; PMCID: PMC4706149.

5:  Wikström M, Hummer G. Stoichiometry of proton translocation by respiratory complex I and its mechanistic implications. Proc Natl Acad Sci U S A. 2012 Mar 20;109(12):4431-6. doi: 10.1073/pnas.1120949109. Epub 2012 Mar 5. PMID: 22392981; PMCID: PMC3311377.

5:  Jones AJ, Blaza JN, Varghese F, Hirst J. Respiratory Complex I in Bos taurus and Paracoccus denitrificans Pumps Four Protons across the Membrane for Every NADH Oxidized. J Biol Chem. 2017 Mar 24;292(12):4987-4995. doi: 10.1074/jbc.M116.771899. Epub 2017 Feb 7. PMID: 28174301; PMCID: PMC5377811.

7:  Toda C, Diano S. Mitochondrial UCP2 in the central regulation of metabolism. Best Pract Res Clin Endocrinol Metab. 2014 Oct;28(5):757-64. doi: 10.1016/j.beem.2014.02.006. Epub 2014 Mar 7. PMID: 25256770.

8:  Giorgio V, Fogolari F, Lippe G, Bernardi P. OSCP subunit of mitochondrial ATP synthase: role in regulation of enzyme function and of its transition to a pore. Br J Pharmacol. 2019 Nov;176(22):4247-4257. doi: 10.1111/bph.14513. Epub 2018 Nov 28. PMID: 30291799; PMCID: PMC6887684.

9:  DiMauro S, Garone C. Historical perspective on mitochondrial medicine. Dev Disabil Res Rev. 2010;16(2):106-13. doi: 10.1002/ddrr.102. PMID: 20818724; PMCID: PMC3839238.

10:  Voet D, Voet JG. Electron Transport and Oxidative Phosphorylation. In: Biochemistry, 2nd Edition. New York: John Wiley & Sons, Inc;1995: 563-598.

11:  Kurz FT, Aon MA, O'Rourke B, Armoundas AA. Functional Implications of Cardiac Mitochondria Clustering. Adv Exp Med Biol. 2017;982:1-24. doi: 10.1007/978-3-319-55330-6_1. PMID: 28551779; PMCID: PMC7003720.

12:  Deshpande OA, Mohiuddin SS. Biochemistry, Oxidative Phosphorylation. [Updated 2021 Aug 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK553192/

13:  12:  Vacas S, Kurien P, Maze M. Sleep and Anesthesia - Common mechanisms of action. Sleep Med Clin. 2013 Mar;8(1):1-9. doi: 10.1016/j.jsmc.2012.11.009. PMID: 28747855; PMCID: PMC5524381.


Graphics Credit:

 Mitochondria graphic is my modification of a VisiScience slide per their user agreement for non-commercial use.

Supplementary:

1:  The Krebs cycle, citric acid cycle, or tricarboxylic acid cycle occurs only in the mitochondrial matrix basically converting chemical energy into the reducing power of NADH for ATP synthesis from electron transport.

2:  Additional review on mitochondrial dysfunction and Alzheimer's Disease:

Misrani A, Tabassum S, Yang L Mitochondrial Dysfunction and Oxidative Stress in Alzheimer’s Disease.  Front. Aging Neurosci. 2021; 13:617588. doi: 10.3389/fnagi.2021.617588