View Full Version : Quick question about dexedrine.


Musiscience
12-02-14, 01:20 PM
Hi there! It has been quite a long time since my last post, at least a couple of years. Glad to be back though, I will try to be more present around these parts in the near future :)!

Here is a quick background of the dilemma I am facing at the moment. For the last 2 years I have not taken any ADHD medication and I am currently doing my masters degree. I have been quite fine for all this time except for the last 2 or 3 weeks where I lost my motivation, energy and concentration. This loss of motivation followed a very rough month of non-stop work and study and I was blaming it on tiredness, but was nervous since I didn't gain back my energy and final exams are approaching. Also, I will say that my grades are above average without medication and I have usually no huge problems on most days to sit down and do my work.

I have just been prescribed dexedrine 5mg 2x a day by my doctor by my demand because of the loss of concentration I just mentioned. I am now on my 4th day of treatment. The problem is, I don't really like it or how it is affecting me. I have been doing sports 4 times a week for a long time and now I can't even hit the gym because when I do I feel weak and out of breath. Also, it has been helping me to do my work for the first day but now I just feel weird and confused, in a non-concentrated way.

Here are the questions I am asking myself at the moment :

-Will I get withdrawal symptoms if I stop the medication now after 3 and a half day of treatment at 10mg a day? If so, how long will it last, I have 3 big final exams in exactly one week :eek: . I have been reading that some of you had bad withdrawal symptoms for months after taking the medication and the last thing I want now is a rebound effect before my exams. For example, being even less concentrated than I was before I took the medication.

-Is this «confusion feeling normal»? I feel a bit like I am sleepwalking and dead inside while I take it. Is it normal that I feel like I think and learn better off of the medication I am taking?

-Should I just take for granted that I don't need medication anymore since I have been doing well organizationally and academically for all these years?

Thank you so much for taking your time to read my post, it is very appreciated! :D

Musiscience
12-02-14, 03:07 PM
Somebody? Anybody? help... lol

Traveler5
12-02-14, 06:25 PM
Everybody is different in how they react when they withdraw from a med. With that said, I really doubt that you'll have any kind of a reaction if you've been taking the med for just 3 days -- but there's always that chance . . . You would most likely know after day 2 of not taking Dex if there will be a problem. My suggestion is to stay on the med and tough it through for the next 4-5 days to see what happens. I suspect you'll start to see more good coming from taking Dex than any bad. It should help you with your school work.

I don't recall any feelings of confusion while ramping up on Dex, but like I said, it's different for everyone. It is very common to experience some bumps when getting up and going on Dex. Problems like increased anxiety, headaches, irritability, heart palpitations, and tiredness are common. "Confusion" may be one of YOUR particular bumps. You really need to give Dex at least a couple months in your system for it to finally level off and for you to become adjusted to the med.

I have to assume at some point in the past you were struggling with various symptoms of ADHD then later on things got better for you for some reason. I have never heard of ADHD going into remission on a person but I guess it's possible depending on what's going on chemically in your brain. Any brain injuries lately? ADHD maybe back for you. If you're starting to feel and see the same old symptoms of ADHD coming back then I'd say ADHD really never left you, you just got lucky because it took a break from doing its thing all those years. You will just have to wait and see what happens. Maybe it will go away again.

Pilgrim
12-02-14, 09:10 PM
Don't stop the medication. Your body is adjusting to it.
You learn better on it once you get used to it.
Why did you start taking it?

Musiscience
12-02-14, 10:25 PM
I had a «down» after some rough weeks in university and started to fear that it would affect my final exams since I had a hard time getting back on my feet. I asked my PD if I could try this as a last resort for my exam period. For the record, I tried every other treatment on the market but this one before and can't tolerate a single one of those, I am really sensible to medication. I was just wondering if all the side effects I get at the moment are there for the long run or they will subside with time. I really feel like my learning capacities are decreasing on the dexedrine at the moment, quite the opposite of what it should do, but I can surely sit for extremely long periods of time without any problem. Also the impact on my physical condition is something that worries me a LOT, I spent so much time getting in shape that I don't want to loose all that over a pill. At least it's better than ritalin, I can always tell myself that :lol: !

That is why I am seeking the wisdom of those who took it for a long time

:thankyou: for your answers, it's really helping me a lot with my decision making and I really appreciate it!

Edit : Traveler5, my symptoms used to be much worse, but they lifted quite a bit after I discovered I was intolerant to gluten and cut it from my food. Now, some days are really worse than others I would say. I know ADHD never really left me, I still feel it, but it's much less severe than it used to be in the past. I really hope it is not coming back full force for the long run. Also by «all these years» I mean the last 2 years :) just clearing that up.

Greyhound1
12-02-14, 11:22 PM
I would suggest lowering your dose for sure. It takes some time for your body to adjust to the medication. You don't want that distraction during exams.

I would lower dose until you experience more benefit than side effect for now. Your body can adjust faster to a lower dose and hopefully, you will experience some benefit. I doubt withdrawal would be much of an issue though, if you stopped without weaning now.

Pilgrim
12-03-14, 01:35 AM
Yeah the lower dose should help.

someothertime
12-03-14, 05:18 AM
you started it for a reason... it's part of the prescribers job to inform and monitor your tapering adequately to keep these fluctuations and potential negative effects to a minimum...

Alas time and some degree of imbalance is part of the treatment process... so like other i'd advise you stick with it providing the prescriber is informed and has no objections...

I would anticipate it would be necissary to adjust your dose as the others have mentioned... my gut says up tho'... though... it is important to do such things usually over a few weeks.... with Dex... a few days ( 5 ) aka... slowly..... as that is also part of keeping things as safe / effective as they can be....

Summary.... keep your presecriber informed and be patient ( 10 days at a timeish )

Musiscience
12-03-14, 09:47 AM
Thank you so much for the info, I will lower my dosage and see if it helps. But like greyhound just said, I might wait after my exams before I start again at a lower dose, just so I won't be in an adaptation period during a very important week. :)

sarahsweets
12-03-14, 10:55 AM
If eliminating gluten from your diet lifted adhd symptoms then I doubt you have ever had it to begin with.

Musiscience
12-04-14, 08:59 AM
They became less severe for sure, but a part of them remained. Gluten was just making my ADHD way worse than it was to begin with. I still struggle to listen to what people say and not interrupt in a middle of a sentence, or doing anything when there is noise around me, or forgetting things all around the place (happily I have good friends who pick them up for me most of the time, like phone and wallet).

Edit : Back to the dexedrine, I stopped 2 days ago and I have a withdrawal happening at the moment. I am extremely extremely tired and depressed since I stopped and if it's not back to normal tomorrow I will take back the dexedrine.

Kunga Dorji
12-04-14, 10:04 AM
Hi,
my own approach (as a prescriber and an ADHD patient) is that in the early phases of treatment that continuous treatment is important.

There is a simple reason for this- if the receptors for your medication are kept saturated at the same level- then you have every reason to believe that fluctuations in your real time performance are not related to changes in the medication- that there are other issues you need to handle.

Most people I see progress from smaller doses more often to larger doses less often.
Habituation to the sympathomimetic side effects of the medication probably explains that.
My own personal regimen went from something like 10mg dex 5 times daily to 20-15 -15 until ai had some complementary treatment and learned meditation.
Then the dose dropped sharply to 25 mg as a single morning dose- then down to 20- 15-10 then zero- over about 3 months.

Then a personal crisis supervened- and 18 months later went back to 15 mg twice daily.
Things have settled now- and this week I have worked 4 10 hour days- dealing with complex problems.

I got home from a holiday on Sunday night at 1am Monday and did not get to bed till 2am. I needed a single dose at lunch on Monday and nothing on Tuesday or Wednesday.
Today I was called back for an emergency and took 10mg at 6pm.
7 hours later - it is bedtime.

The short answer is- that as I see it- the required dose for anyone who has been handling ADHD for a few years is very variable.
Chemical habituation is a minor, but real issue, and 6 years after my own diagnosis of ADHD I prefer to be serious about self care and keep the medications for the times when nothing else works. That way I know I always have a back up strategy for those "brain dead days".

Musiscience
12-04-14, 01:46 PM
Thank you so much Kunga, your opinion and advices are really invaluable to me. The big problem I face is that I don't learn the same way when on the medication so I don't really remember the things I learned when not taking and vice versa. For example, I am more a marco thinker when I am off medication and a micro thinker when on medication and these are 2 completely different ways to learn the same things for me. I am way more comfortable learning in a macro way because it gives me a broader understanding of things.

The thing is, I really goofed up, because I should have waited after my finals to start the treatment and now I want out but I can't because it leaves me tired, depressed and empty minded.

In your practice and your own experience, how much time will it take for my body to go back to normal from the state I am in?

Thank you so much in advance, I am really a wreck at the moment.

dvdnvwls
12-04-14, 03:52 PM
It takes from one to three days to get back to normal, no more.

If you've been feeling tired, depressed, and empty-minded from your medication, it's a nearly certain sign that your dose was too high for you. (It's also possible that you were taking exactly the right dose but let yourself become badly dehydrated - it happens.) If you keep taking a reduced amount, it's very likely that you'll get better results than if you stop altogether.

Musiscience
12-04-14, 04:19 PM
Thank you for the advice, it is good to know that it should get better soon. Someone in another thread also said that Vit C and good hydration can help, I will try that too :).

Kunga Dorji
12-06-14, 07:20 AM
Thank you so much Kunga, your opinion and advices are really invaluable to me. The big problem I face is that I don't learn the same way when on the medication so I don't really remember the things I learned when not taking and vice versa. For example, I am more a marco thinker when I am off medication and a micro thinker when on medication and these are 2 completely different ways to learn the same things for me. I am way more comfortable learning in a macro way because it gives me a broader understanding of things.

The thing is, I really goofed up, because I should have waited after my finals to start the treatment and now I want out but I can't because it leaves me tired, depressed and empty minded.

In your practice and your own experience, how much time will it take for my body to go back to normal from the state I am in?

Thank you so much in advance, I am really a wreck at the moment.


There are a couple of points to be made here- I have had some interesting conversations with my chiropractor in the past few days- and especially this morning. Ian is a very cool guy and far more neurologically literate than ANY doctor I have met-- in terms of breadth of clinically applicable knowledge I suspect he is well beyond even Antonio Damasio (who I have not yet met).

Coming from "chiro land" he has usually been very "anti- medication"- but as time has gone on he is beginning to see that there is a real role for medications if we understand how they work.

So-
1) Stimulants, on average, enhance learning capacity- even in neurotypicals.
2) Overly high doses will cause cognitive rigidity.
3) Individual response to stimulants is exceptionally variable.
I have known patients respond well to 2.5mg dexampetamine 3 times daily and others who have needed 40mg 3 times daily. Some others have used doses of over 100mg 3 times daily ( in selected patients and with careful and supervised dose titration).

Now, I think the big catch here is the stress response.
Stimulants have a "sympathomimetic effect"- ie they turn on a stress response.
Most of the side effects- muscle tension, tooth grinding, tics, palpitations etc are symptoms of a stress response. "Anxiety" is another symptom of a stress response- as is cognitive rigidity.

So - if in any individual the stress response effect outweighs the other effects- maybe the results are not going to be so good.

The good news here is that the stress response side effects of stimulants are prone to wear off as we adapt to the medication.

So an individual might start on a low dose and then build the dose as the stress response side effects subside.

In the context of these considerations the answer to achieving a good effect might be as simple as a smaller dose and some relaxation training.

Now the other question is the persistence of side effects and adverse reactions.

Stimulants do not, of themselves, cause irreversible changes, except in massive overdose- when they can be fatal.

Other drugs do-- ie venlafaxine (AKA Efexor,an antidepressant) is well known to cause a withdrawal syndrome that can take a year to recover from.

In clinical pharmacology, the most important consideration is the half life of the medication.

Elimination of a drug from one's system operates via an exponential curve. In one half life-- 1/2 of the circulating drug is eliminated from one's system.
In 2 half lives the amout remaining is (1/2x1/2)= 1/4 of the original dose persists in one's system.

It is commonly accepted in medicine that by the time 5 half lives have passed 31/32 of the original dose has been eliminated and at that point the remaining level is regarded as not clinically relevant.

We are told that the window of effect of dexamphetamine is 4-5 hours.
However the half life is said to be 10-11 hours.

So - in terms of side effects- you should not be experiencing any after 5x11 hours have passed.

Sometimes an experience with a drug (or other agent) can be really scary- and that can leave a lasting imprint. An example here is sleep paralysis. I have had this a few times- but it took me almost a year to realise that I had a huge stress reaction every time I remembered the first event.That was a few years ago- before my more intensive meditation training.

However- the stress response is a tricky thing, and even quite unskilled people can learn how to turn it off.

I meditate quite a bit- and can recognise a stress response quite fast- and I know when I should take dexamphetamine and when not to bother.
However, I know that I never function well if stressed -maybe I am unique here?:)

I also know and can find scientific papers to prove it, that dex improves learning-- so I use the stuff to learn how to recognise my stress level and how to adjust it appropriately if I need.

So- usually, if I need medication- a single dose will be enough to turn my system on properly and I will not need another dose for the rest of the day.

This stuff is seriously interesting-- stimulants are exceptionally powerful AND subtle medications.

What all this means to me is that we have to be careful when using them, and patient enough to work through any teething problems we encounter when we are started on them.

Next month marks the start of my 30th year as a practicing doctor. I have used a huge array of medications in that time- and seen all kinds of issues with medications, up to and including unexpected fatalities.

Stimulants remain the single most powerful, versatile and safe agents that I can legally prescribe.

Musiscience
12-06-14, 08:51 AM
Kunga Dorji,

All I can say is wow! I can't be thankful enough for that post, I am speechless.

I can really relate to a lot of info here. People do have a very variable response to stimulants. I knew some people who had to take an incredible amount of stimulants just to get a small effect, while I take a very small amount and it sends me to the moon and back.

Actually, I had problems with stress response with all stimulant medication with the smallest dose possible and was told that the dexedrine was very «smooth» compared to other drugs. For me, it is not smooth at all for the moment, while I sticked with the treatment, I almost had a panic attack last night and told myself I would take a few days off.

Stress response is a big problem for me, but I was able to control it while off medication with meditation sessions. Meditation has been a life saver for me actually, really put things in perspective and gives me a calming sensation.

Also, I had the displeasure of experimenting that awful venlafaxine withdrawal in the past and it took me quite a while to recover from it. I see the parallel you are making here, with stimulant medication, usually takes 2-3 days is enough to be back to normal.

That is comforting to know that my bad experience will end in less than about 50 hours. From my recent and past experience, I really think that this time, it was my last experience with stimulant medication. From now on I will keep relying on exercise, alimentation and meditation to manage my symptoms, seems to be the most appropriate way for me at least.

Also, congratulations on your 30th year, that is quite the milestone in a career! Must feel good to know that you have accomplished so much with you life while looking back.

:thankyou: so much again, I feel grateful that there is a community I can rely on to help me with something most people would not understand or know how to deal with.

Kunga Dorji
12-06-14, 03:53 PM
Kunga Dorji,

All I can say is wow! I can't be thankful enough for that post, I am speechless.

I can really relate to a lot of info here. People do have a very variable response to stimulants. I knew some people who had to take an incredible amount of stimulants just to get a small effect, while I take a very small amount and it sends me to the moon and back.

Actually, I had problems with stress response with all stimulant medication with the smallest dose possible and was told that the dexedrine was very «smooth» compared to other drugs. For me, it is not smooth at all for the moment, while I sticked with the treatment, I almost had a panic attack last night and told myself I would take a few days off.

Stress response is a big problem for me, but I was able to control it while off medication with meditation sessions. Meditation has been a life saver for me actually, really put things in perspective and gives me a calming sensation.

Also, I had the displeasure of experimenting that awful venlafaxine withdrawal in the past and it took me quite a while to recover from it. I see the parallel you are making here, with stimulant medication, usually takes 2-3 days is enough to be back to normal.

That is comforting to know that my bad experience will end in less than about 50 hours. From my recent and past experience, I really think that this time, it was my last experience with stimulant medication. From now on I will keep relying on exercise, alimentation and meditation to manage my symptoms, seems to be the most appropriate way for me at least.

Also, congratulations on your 30th year, that is quite the milestone in a career! Must feel good to know that you have accomplished so much with you life while looking back.

:thankyou: so much again, I feel grateful that there is a community I can rely on to help me with something most people would not understand or know how to deal with.

Venlafaxine is a nasty drug- I doubt I will ever initiate it again.

It is a shame that they don't suit you.

I have had further big improvements myself with 4 major additions to basic meditation and medication.

1) Postural and spinal alignment correction.
2) Pushing salt and water intake to ensure adequate blood volume
3) Movement mindfulness and balance training (Tai Chi/ Qi Gong)
4) Relentless attention to sleep hygeine and training in rapid wake up techniques.

and am finding that my stimulant requirement is getting more and more sporadic.

I have a very solid case series now and am finding that problems with balance and coordination - (usually driven by spinal malalignments in the neck distorting body position awareness) are virtually universal in ADHD.
This make sense, as movement and attention really do involve the same neurological pathways. (Ref Spark, Dr John Ratey).
I have worked with my chiropractor for a long while now to stabilise this situation, and this year found that what was really needed to capitalise on those benefits was the addition of Tai Chi and Rhytym meditation (Ta Ke Ti Na). The latter is especially good for stimulating basal ganglia and vestibular system and the former for vestibular system and improving spinal alignment, posture and flexibility.

Of the Tai Chi the most useful elements have been Qi Gong (translates as "energy work" and really does help you come to a relaxed alertness very fast) and the basic Tai Chi walking. This has really improved my alertness and co-ordination. Now that I am not bumping into things and dropping things that frees up a LOT of working memory. Also the poor balance and coordination so prevalent in ADHD does cause a persistent underlying stress response.
I am finding that my learning ability has hugely improved- and rote learned the vajrasattva mantra last week-- 100 syllables and in a foreign language, which I do not speak. I have struggled with that one for years.

The other big surprise has been the fluid balance thing. I have done a post elsewhere on "orthostatic intolerance" as a driver of ADHD- and I am seeing it in most ADHD individuals (say 90% of those I have tested in the last 10 weeks). This is effectively leaving us with relative lack of blood perfusion to the brain when we sit or stand for long periods and that causes a big stress response.
So a healthy person will have only a brief and intense acceleration in heart rate on standing (ie increase of 10-15 beats/minute on standing, but settling to maybe 5 beats per minute after a minute-- but those of us with orthostatic intolerance have a much longer acceleration in heart rate on standing- and often go very pale in the face when sitting or standing for long.

It is reasonably easy to improve for most- just more water and salt, care to avoid overheating or big meals when I have to work later, caution with alcohol (causes facial flushing- diverts blood volume away from the core) and posture/core tone work + abdominal breathing (increases intra-abdominal pressure and stops venous blood pooling around the intestines- easiest done by learning standing Tai Chi meditation- which only needs to be done for 5 minutes or so at a time).
A few individuals need much more work than this- specialised medication- but that is uncommon.

I am very excited about this orthostatic intolerance thing- it makes physiological sense and fits in with the SPECT and PET scan data on ADHD. My colleagues and I are now working to secure research interest to bring this knowledge into the mainstream of "evidence based medicine". Honestly, it is a genuine and major breakthrough.

Thanks for the congratulations--I think what I have been able to do so far is a sign of what ADHD people are capable of-- but now that the ADHD is so minimalised I am aiming for much bigger things. The research may well make my reputation as widely known as Daniel Amen if I can work out how to manage the organisational things-- which I do not enjoy.

Musiscience
12-15-14, 12:14 PM
Kunga, thank you so much again for the very elaborated answer. I am really sorry I could not answer earlier since I just got out of a very intense exam period.

What you say about orthostatic hypotension is very, very interesting. I have suffered from severe hypotension for years now and every doctor I have seen just dismiss it as being nothing. When I take a hot bath or shower I am completely out of it for the rest of the day so I usually try to avoid them most of the time (in Canada, a cold shower in the winter time, when it's -15 Celsius outside is really depressing). I can't believe there is a good chance they are related, makes so much sense and explains so many things. I really hope you and your colleagues pursue research in this subject, since it is so very interesting. If you do I am very interested in reading the paper.

Another thing you have said that is particularly striking to me, is the sleep hygiene and rapid waking, especially the waking part. I have realized in the last year that I function much, and I mean MUCH, better when I try to get out of bed as soon as the alarm buzz. I have easily 2 times more motivation and actual intellectual capacities when I do that. It is, in my opinion, a very neglected part of sleep hygiene. Those of us who consulted for practical ADHD management know it is necessary or at least strongly recommended to get to sleep and wake up every day at the same time, but they never talk about how we should wake up rapidly and not snooze a couple of time. This should be studied more, in my experience the impact on functionality is major.

On the other hand I never understood the link between coordination and ADHD, at least theoretically, I think I will read a bit on the subject in the next days, this is pretty interesting.

I will remember your name for searches on pubmed in the future, (should not be very hard since we share the same name!), I really think you are onto something that could help a lot of ADD and ADHD people!

Thanks again and see you around!

Kunga Dorji
12-15-14, 04:26 PM
Kunga, thank you so much again for the very elaborated answer. I am really sorry I could not answer earlier since I just got out of a very intense exam period.

What you say about orthostatic hypotension is very, very interesting. I have suffered from severe hypotension for years now and every doctor I have seen just dismiss it as being nothing. When I take a hot bath or shower I am completely out of it for the rest of the day so I usually try to avoid them most of the time (in Canada, a cold shower in the winter time, when it's -15 Celsius outside is really depressing). I can't believe there is a good chance they are related, makes so much sense and explains so many things. I really hope you and your colleagues pursue research in this subject, since it is so very interesting. If you do I am very interested in reading the paper.

Another thing you have said that is particularly striking to me, is the sleep hygiene and rapid waking, especially the waking part. I have realized in the last year that I function much, and I mean MUCH, better when I try to get out of bed as soon as the alarm buzz. I have easily 2 times more motivation and actual intellectual capacities when I do that. It is, in my opinion, a very neglected part of sleep hygiene. Those of us who consulted for practical ADHD management know it is necessary or at least strongly recommended to get to sleep and wake up every day at the same time, but they never talk about how we should wake up rapidly and not snooze a couple of time. This should be studied more, in my experience the impact on functionality is major.

On the other hand I never understood the link between coordination and ADHD, at least theoretically, I think I will read a bit on the subject in the next days, this is pretty interesting.

I will remember your name for searches on pubmed in the future, (should not be very hard since we share the same name!), I really think you are onto something that could help a lot of ADD and ADHD people!

Thanks again and see you around!

Hi,
There are a couple of useful points following on from this:
1) The orthostatic intolerence nexus is not present in all people I have examined.
2) The orthostatic intolerance issue is way worse in individuals with poor posture.
3) Orthostatic intolerance is also worse (as is posture) in individuals with a chronictrauma history-- and this appears to be due to facilitation of the freeze response, which becomes recruited as the default mode response to negativity or stress. (Many ADDers have suffered repeated traumas- people can be really nasty to us- and that usually trips us into dysfunction).
4) The quick get up makes a huge difference to me- but it was painful training it in.
5) Re Showers- have you experimented with warm but not hot- then running it cold at the end? That would logically make sense.
6) Re Orthostatic intolerance in general- this is easy to monitor yourself.
- Home blood pressure monitors are inexpensive now- easy to do your own stand up test
Also IPhone apps like Instant Heart Rate-
Resting heart rate seated should be low 70s and on standing briefly spike about 10-15 beats before settling about 5 beats higher than standing.

Re movement - the best and cheapest place to look is the chapter on ADHD in John Ratey's book "Spark"
There is a good deal covered in Manual Therapy in Children by Heiner Biedermann:
notably section1
Particularly:
Chapter 2 Sensorimotor development of newborn and children from the viewpoint of manual therapy.
Chapter 5: Adaptive properties of motor behaviour
and
Chapter 6: Neuromotor development in infancy and early childhood.


All in all I am finding this very interesting- and being pleased with my own improved functionality as well as the results I am seeing in others.

Plus - it is WAY LESS BORING than what I was doing-- and that is always good for anyone with ADHD:)

Musiscience
12-16-14, 11:37 AM
Again, thank you so much for the info, I will look into training myself to get up slowly not to get the hypotension. I have noticed that regular cardio has helped a bit with hypotension, probably due to a better basal blood pressure and heart function?

One thing is for sure, medication, while it helps a lot of people, is not for me and I will stop pursuing this avenue.

Way less boring, indeed haha. I have a paper to write at the moment, yet here I am roaming on forums haha.

Kunga Dorji
12-17-14, 05:37 PM
Again, thank you so much for the info, I will look into training myself to get up slowly not to get the hypotension. I have noticed that regular cardio has helped a bit with hypotension, probably due to a better basal blood pressure and heart function?

One thing is for sure, medication, while it helps a lot of people, is not for me and I will stop pursuing this avenue.

Way less boring, indeed haha. I have a paper to write at the moment, yet here I am roaming on forums haha.

The exercise effect is probably more likely due to a better trained autonomic nervous system.
Interventions like short burst interval training or standing in the shower and alternating hot and cold water have proved the most helpful for me.
Also I do things like deliberately visualise myself standing before I get up, and be sure to never lead off from sitting with my head. Keeping my neck back and my spine straight,, and chest forwards helps me vastly.
Finally three or 4 quick squats on standing and some abdominal breathing help maximise venous return from the legs and the gut.

Also- there is a relative blood volume problem as well.
My issues have receded greatly since a Chinese Medicine doctor told me to drink 600ml of lukewarm water on rising.
That expands blood volume pretty fast when done on an empty stomach and the effect persists for 60 to 90 minutes.

I have had a problem with severe unpredictable sweating for some years, and have, only this year, been able to turn it off.
It was causing significant loss of salt and water and leaving me with relative dehydration as my default state.

It is only recently that I discovered that the sweating was due to acute stress reactions caused by loss of balance when my neck went out of alignment. 10 months of Tai Chi, and lots of bodywork (chiropractic and massage) have nearly fixed that- though- and I think I am close to full resolution of the neck problem.