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Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 7 to 31 of 35. Go back in thread:
Posted by Racer on October 24, 2000, at 18:44:15
In reply to Fainting, posted by noa on October 24, 2000, at 7:22:58
Noa,
I haven't fainted on Effexor, but I've fainted for other reasons many times. It's always best to get checked out, especially after a med change, but here are some other reasons it could have happened:
1. postural hypotension sounds likely, and it's easy to check out whether it's likely. Many ADs effect blood pressure.
2. Effexor has sent my blood sugar readings all over the board. I've gone through bouts of readings higher than I've ever experienced before, and some lower than I've experienced for years -- despite what I've eaten. Talk to your doctor about this if you have any other indicators at all for diabetes. If the doctor won't discuss it, put together a food diary for yourself. List what and when you eat, and what you feel like: if you're overtired after eating, if you feel shaky before eating, etc. It won't diagnose anything, but it might show you a pattern you can show your doctor.
3. Alien abduction. This last one isn't very likely, unless you noticed crop circles on the carpet when you came to, but I wanted to make you smile!
Good luck, and don't do it again! I think you can find yourself a much better hobby if you try!
Posted by Racer on October 24, 2000, at 18:53:42
In reply to Re: Fainting » noa, posted by Racer on October 24, 2000, at 18:44:15
Duh, forgot to mention this part:
I have fainted in dangerous situations, and it's terrible. I've fainted in public places, on busses, on horseback (!!), and in the shower. The scariest part about fainting in public is that my fight or flight reflex kicked in, and I was basically trying to run away to be alone when it happened. Think about the danger in that! One of the fainting on the bus incidents happened when I could feel it coming on, and tried to get off the crowded bus. Fortunately, the bus had just gone past UCSF and a resident saw me and recognised the symptoms -- she stopped me getting off the bus, and shook me back to conciousness. Still, if she hadn't, I could have been lying on the street for a long time.
Another time, I got hit by vertigo in downtown San Francisco on my way home from work. I was just over a cold, and my ears had gotten infected, and this was the first attack of vertigo I'd ever had. Suddenly I lurched across the sidewalk, grabbed onto a brick in a wall, and tried to get help. You know what? No one would help me. I used all the techniques I've been told to use in an emergency: "Miss, in the red sweater, will you call an ambulance", etc. You know, specify a person, speak directly to one person rather than a group, but it seemed that everyone assumed I was drunk, or high, or nuts, and no one would even look at me. Thankfully, that was vertigo and not fainting, but it was still terrifying. The point is, if it happens outside, don't expect help. So, find out what the problem is, fix it, and don't go out alone until you do.
The times I've fainted in the showers, it's ALWAYS been hypoglycemia. The trouble stopped when I changed my habits and started eating breakfast BEFORE my shower, with no fruit juice. The fainting started because of a variation on Dawn Phenomena. I would get up, my blood sugar would be high, and in the shower my sugar would drop rapidly, and I'd faint. Scary as hell, especially when you come to and realize what MIGHT have happened...
Posted by medlib on October 24, 2000, at 20:53:16
In reply to Fainting, posted by noa on October 24, 2000, at 7:22:58
Noa--
Ouch! Fainting is no fun at all! Glad you're going to get it checked out--IMO, no episode of syncope is minor.
Reading your description triggered another of my left-field "what if" musings. I wondered if your "black-out" could be cerebral anoxia or vasovagal syncope from a combination of yawning, sitting and meds.
I remember how dizzy I felt starting (and increasing) Effexor. Changing positions and walking made it worse; I assumed that it was orthostatic hypotension due to Effexor's tendency (in some) to cause peripheral vasodilatation. This effect always wore off in a couple of weeks, but my toes and lower feet are still red. Your "greying out" under similar circumstances makes me wonder if you are still having some circulatory effects from Effexor.
I remember also that you may have a narrowed upper airway passage (difficulty swallowing large pills and cpap for sleep); it struck me that a giant yawn might completely obstruct your airway briefly. I envisioned that, during such a yawn, you might tilt your head up or down (most of us do), possibly compressing arteries in your neck. If enough blood is shunted away from the heart and head to the periphery, it might not take much compression of the cerebral arteries or carotid sinuses to cause unconsciousness.
BTW, I believe that Adderall can stimulate yawning (because of its effect on dopamine transmitters).
In any case, I would be sure to apprise the doctor of your past "greying out" experiences; and I think I'd try to avoid yawning while driving--at least until this is IDed! Please ignore this wild guess if it seems as unlikely as it sounds, or is otherwise inapplicable.
Hope your internist is a good diagnostician and is able to pinpoint what's wrong quickly. If she orders blood work, having it done fasting (yeah, I know it's a pain) and including a CBC would rule out anemia or blood sugar problems as possible causes. Please keep us posted.
Well wishes---medlib
P.S. I noticed in the Effexor lit that it is compounded with iron oxides. If that type of iron is bioavailable, it's less likely that you have iron-deficiency anemia. Wonder *why* they formulated it with iron?
> I fainted this morning. I was sitting at my computer, and yawned, and felt myself begin to black out. Now, I have "greyed" out in the past, not much recently, but when that happens, I haven't actually blacked out--until today.
>
> But today, I felt myself black out, and the next thing I was aware of was dreaming, and waking up with a bad pain on the side of my head. Then it took a few seconds to realize I was on the floor. After that, a few seconds more to figure out where on the floor, and still more seconds to figure out what happened.
>
> There is a a tender spot on the right side of my head but the all-around headache I felt for about 30 minutes after getting up, is gone.
>
> I am so glad this happened from sitting in a chair and not in the shower!
>
> The thing is, if I had been in the shower, I like to think I would have braced myself but because I was in a chair I didn't think anything could happen. Ok, that is naive. I was basing it on the experience of having nearly blacked out lots of times in my life but not actually blacking out.
>
> The "greying out" used to happen a lot when I was taking higher doses of regular effexor several years back. It would happen when I yawned a big yawn, laughed really hard, or stood up fast.
>
> I hope this is not due to the Adderall, which is the latest med added to my cocktail. Any thoughts?
>
> Another possibility is that it could be related to having missed a few of my cytomel and serzone doses a few days back.
>
> Also, once about 17-18 years ago, I fainted due to low iron. I guess I should check that out.
>
> If any of you thinkit might be med related, please comment.
Posted by Racer on October 24, 2000, at 22:11:13
In reply to Re: Fainting, posted by medlib on October 24, 2000, at 20:53:16
> Hope your internist is a good diagnostician and is able to pinpoint what's wrong quickly. If she orders blood work, having it done fasting (yeah, I know it's a pain) and including a CBC would rule out anemia or blood sugar problems as possible causes. Please keep us posted.
Actually, this wouldn't necessarily rule out glycemic trouble. My problems only became apparent with a four hour GTT, fasting glucose didn't show much of anything at all. The GTT did show strange results, though it was some years later that the full extent of the problem became clear. (It took a carefully controlled diet and exercise program, and faithful recording of food/exercise/blood sugar readings on a good glucometer to show everything that was happening.)
Regardless, I'm with you on sending noa good wishes.
Posted by medlib on October 25, 2000, at 2:34:12
In reply to Re: Fainting, posted by Racer on October 24, 2000, at 22:11:13
> > Hope your internist is a good diagnostician and is able to pinpoint what's wrong quickly. If she orders blood work, having it done fasting (yeah, I know it's a pain) and including a CBC would rule out anemia or blood sugar problems as possible causes. Please keep us posted.
>
> Actually, this wouldn't necessarily rule out glycemic trouble. My problems only became apparent with a four hour GTT, fasting glucose didn't show much of anything at all. The GTT did show strange results, though it was some years later that the full extent of the problem became clear. (It took a carefully controlled diet and exercise program, and faithful recording of food/exercise/blood sugar readings on a good glucometer to show everything that was happening.)
>
> Regardless, I'm with you on sending noa good wishes.
Racer--You're right, of course. That comment was a last minute (clearly, not-thought-out) afterthought, and I shouldn't have been so glib, or so general. I was thinking more of frank diabetes than of hypoglycemia or other less clear-cut blood sugar abnormalities. For someone who passed out in the 4th hour of a 6 hour GTT at age 13 (and had 2 hypoglycemic kids), it's a puzzling error, to say the least.
Thanks for the heads up!---medlib
Posted by Noa on October 25, 2000, at 13:58:25
In reply to Re: Fainting » Racer, posted by medlib on October 25, 2000, at 2:34:12
Thanks, everyone.
I just came from the doctor. After checking me out for concussion, etc., they had a mini-conference of nurses and docs in the hallway, to figure out why I fainted. They decided it is most likely a vasovagal faint from the big yawn, stretch. They advised for now to chill my yawns out a bit, not to bend my neck back or press down if sitting, while yawning, and no huge yawn/stretch combos. But that if it continues, they will send me to a neurologist for eval.
My heart and breath and blood pressure all checked out ok, and my neck arteries sound good, they say.
I just looked up vasovagal syncope on pubmed and apparently, it is quite common. There is a diagnostic procedure called the Head UpTilt Test (HUTT) but I haven't found a good description of what it is. I imagine it involves tilting the head up and back, which puts pressure on the neck, and vasovagal nerve. Does anyone here know more about it?
I feel fine today, just a bit of a headache, and a tender minor lump on the side of the head, plus one sore spot on my shoulder.
Funny thing, when the nurse practicioner came back in to talk to me after the "mini conference", she started yawning a lot! When I said I think I had infected her, she told me that while the bunch of docs and nurses were discussing this in the hall, they all started yawning all of a sudden!
Posted by dove on October 25, 2000, at 14:10:55
In reply to Fainting, posted by noa on October 24, 2000, at 7:22:58
I haven't read all the responses to you Noa, I'll do that as soon as I'm done. I have *lots* of experience with greying-out and completely blacking-out! So, I take a few of the same meds as you do, I too have fainted due to severe anemia, I have fainted and afterwards tested positive for hypoglycemia, as well as the occasional positive TSH test(I think that's the name? Positive for "temporary" hypothyroidism -you're the pro on that one Noa!).
The combo of my new p-doc forgetting to straighten out my Serzone prescription at my new pharmacy has left me with a mere 300 mgs for since yesterday. Last night this resulted in a massive blinding headache, an extremely queasy feeling, and kind of "out-of-it" sort of thing. I sat around not really doing anything, not reading, just staring off into space. I had the same thing happen for the last 1 1/2 hours, started exactly when I would normally have taken my serzone. Kind of came out of it a little bit ago and saw your message (to which I'm now replying!).
Adderall, I'm taking 40 mgs and have never had a black-out or faint that appeared connected to this med in any way. I've taken Adderall alone, w/ prozac, wellbutrin, amitriptyline, serzone, neurontin, and in a multitude of combinations with those meds, and not once has the Adderall proven to be the problem. Of course, this unfortunately only really applies to me and not necessarily to your situation.
My uneducated guess would be the missed Serzone and Cytomel, with compounding factors such as fatigue (or trying to wake up your body/brain--lack of oxygen--that's the whole purpose of yawning in the first place), and no glucose stabilizing food fueling your brain/body (like protein?). Did you sleep well last night, your apnea still being taken care of?
I am inordinately vulnerable to fainting when I haven't eaten, haven't slept, haven't taken certain meds (Serzone, Neurontin being the biggies at this point),and haven't totally woken up yet, or am getting hit with a second wave of fatigue. I would encourage you to get your thyroid levels checked soon, that might give you some clues. All my prayers and thoughts are with you ((((Noa))))
dove
P.S. I'm sorry Noa, I just noticed that you posted this yesterday! So please read my tone as not so direly urgent :-) You still have my thoughts and prayers, although belatedly.
Posted by dove on October 25, 2000, at 14:15:41
In reply to Re: Fainting » noa, posted by Racer on October 24, 2000, at 18:44:15
I just remembered that one of our psycho-babblers fainted last winter I think? Was it Adam? Sick with the flu and fainted while taking a shower. And his girlfriend found him and he was all beat-up by the evil shower. Was that Adam?
dove
This is all just to let you know that you're not alone Noa. Hope you're feeling better today!!!
Posted by dove on October 25, 2000, at 14:45:44
In reply to Re: Fainting, posted by Noa on October 25, 2000, at 13:58:25
One more little item to add--now that I've read all the responses and know undoubtedly that I must try to read all the responses before impulsively responding to a message--as to prevent blatant reoccurring redundancy.
Now, my dad is hypoglycemic and gets extremely suicidal when his blood sugar decides to take a dive. Until he began an extremely strict diet (sort of like those high protein diets I keep reading about), his moods swung so wide and far that my mother *left* him on a number of occasions, totally convinced that he was truly insane. His hypoglycemia affected every aspect of his life, and only now is he finally stabilizing mood wise.
So... I was thinking that it might be a great idea to get some hypoglycemia info together for that "Links" page on egroups. Such expertise Psycho-babble already has, and I'd hate to see that precious knowledge lost. Anyone interested in doing something like that?
And maybe create a multi-crossing category like "Fainting" or "Black-outs" that would present different characteristics and their implied meaning.
For example: Graying-out while stretching and yawning is more characteristic of "whatever that vaso something was". Adding to the base of layman/working knowledge for recognizing some of these characteristics and when/where to go for help.
Or this might be all to discombobulated and we should just go with straight-forward links to hypoglycemia and depression?
dove (babbling and rambling...)
Posted by dove on October 25, 2000, at 14:48:52
In reply to Fainting, posted by noa on October 24, 2000, at 7:22:58
Do I appear hypo-manic to anyone wading through all my posts? I apologize Noa for dragging your message so completely off course, I think the Neurontin is working a little *too* good.
dove (yet again!)
Posted by Noa on October 25, 2000, at 15:16:48
In reply to Re: Fainting, posted by dove on October 25, 2000, at 14:15:41
Dove, you have a good memory. I remember about the fainting in the shower, and yes, I think it might have been Adam. He seemed to think it was a combo of the flu, easily fluctuating blood pressure due to MAOIs, and the hot water. While I was searching on pubmed today, I did notice a couple of articles on hot bath water as raising the risk of fainting.
Dove, I don't mind the thread detouring. I think my needs were already met.
I asked the various docs, nurses, etc. whether a threshold phenomenon could be part of this vasovagal syncope--ie, things like hypoglycemia (it was 6 am, I hadn't eaten anything yet, but had eaten a whole bunch of very sweet stuff right before going to bed the night before), anemia, medications, etc.--could they lower the threshold for a vasovagal reaction. They didn't seem to think so.
Posted by Noa on October 25, 2000, at 16:38:44
In reply to Re: Fainting, posted by Noa on October 25, 2000, at 15:16:48
I did some more reading online and it turns out the head tilt test involves lying on a table, and then they tilt it from horizontal to either 60 or 80 degrees vertical, and measure heartrate, bp, etc. Some people faint during the procedure, which confirms the v-v syncope dx.
I don't know. I don't think I would faint in that test. I usually have no problem going from sit to stand or lying in bed to standing, although as a teen, I used to "grey out" sometimes.
But I still thing the v-v response makes sense in explaining why I fainted--I think it was the yawn.
Posted by medlib on October 25, 2000, at 17:30:58
In reply to Re: Fainting--Head Tilt Test, posted by Noa on October 25, 2000, at 16:38:44
Noa--
The tilt table test is more demanding than it sounds like. By slow, they mean over a period of 25-45 minutes. I've seen quite a number pass out on it. Many people unconsciously hyperextend or "lock" their knees when reclining/standing in one place for a while--which cuts off venous blood return from the lower legs. This alone often is enough to cause blackout (aka the "Palace Guard Syndrome"). But, IMHO, there's no reason to take a test if nothing is to be done with the results.
Regardless, it's great that you have a presumed dx. If something similar happens again, head between the knees position helps some (if there's time).
Well wishes---medlib
P.S. I yawned through this whole post, as well as the one last night. It's hopelessly contagious!
> I did some more reading online and it turns out the head tilt test involves lying on a table, and then they tilt it from horizontal to either 60 or 80 degrees vertical, and measure heartrate, bp, etc. Some people faint during the procedure, which confirms the v-v syncope dx.
>
> I don't know. I don't think I would faint in that test. I usually have no problem going from sit to stand or lying in bed to standing, although as a teen, I used to "grey out" sometimes.
>
> But I still thing the v-v response makes sense in explaining why I fainted--I think it was the yawn.
Posted by noa on October 26, 2000, at 7:04:58
In reply to Re: Fainting--Head Tilt Test » Noa, posted by medlib on October 25, 2000, at 17:30:58
Thanks, medlib. and LOL about the yawn.
Posted by Greg on October 26, 2000, at 12:46:03
In reply to Re: Fainting--Head Tilt Test, posted by noa on October 26, 2000, at 7:04:58
Noa,
This sounds very simplistic in nature, but I was wondering if they checked you for a possible inner ear problem? I sustained an injury to my left ear as a child and only have about half my hearing in that ear now. When I do things that require me to bend over I periodically get dizzy to the point of passing out. The docs say it's due to the inner ear problem. It just dawned on me that this might be an issue with you.
Just random "babbling".
Greg
> Thanks, medlib. and LOL about the yawn.
Posted by noa on October 26, 2000, at 13:46:19
In reply to Re: Fainting--Head Tilt Test » noa, posted by Greg on October 26, 2000, at 12:46:03
Not simplistic at all, but I had no dizziness before fainting. I have had inner ear infections which cause loss of balance, dizziness and nausea. This was different--it really does fit the vasovagal response thing pretty well.
Posted by danf on October 26, 2000, at 14:42:44
In reply to Re: Hypoglycemia, posted by dove on October 25, 2000, at 14:45:44
some help with vasovagal stuff.
vaso vagal faints are by definition, neurogenic in nature.
some stimulus causes the heart rate to slow down & bp falls. In some, part of the event is mediated by peripheral dilation of the extremities so that blood pools in the extremities & does not go back to the heart quick enough to be pumped out.
Not enough blood goes to the brain & we faint. a short warning of a few seconds is present. While not impossible, one will usually not faint if lying down as adequate blood returns to the heart to keep some perfusion (blood flow) to the brain.
after the BP / HR control 'escapes' from the slow HR, the BP & HR both go 'high' for a short while ( few minutes). this sequence is easy to see if another person is present to monitor BP & HR.
IT can be induced if some one has a sensitive carotid sinus ( 'sensitive carotid sinus syndrome' ) in the neck & is wearing a tight collar for instance, or has the neck massaged.
a mechanism present in some people is putting the head under water ( a variation of the 'diving reflex' ). A deep yawn may trigger a variation of this same reflex pathway.
An interesting sister reflex, is initiation of a sneeze when a bright light is shined in the eyes, or by walking from a shaded room to bright sunlight.
It is unknown why some people have these reflexes activated in a powerful way at times. All people have the reflexes, but they are rarely triggered in such a powerful way. Perhaps some neurologic meds have an influence.
Anything which causes peripheral dilation may cause blood to pool in the extremities & possible fainting. A hot shower or bath are examples. some meds, like aldomet, partially paralize the bodys ability to respond to postural changes.
However these other mechanisms are not vasovagal, by definition.
Posted by laural on October 26, 2000, at 15:50:46
In reply to Fainting, posted by noa on October 24, 2000, at 7:22:58
i don't have time to read this thread but i grey out a lot too. its because i have low blood pressure. i was severely hypoglycemic in high school due to my anorexia i guess and tey gave me these pills that would help but they lowered my blood pressure even more and i could barely do anything, had to do it very slow or else down i'd go. maybe your meds cause low blood pressure-- laural
Posted by SLS on October 26, 2000, at 19:36:19
In reply to Re: Hypoglycemia, posted by dove on October 25, 2000, at 14:45:44
> For example: Graying-out while stretching and yawning is more characteristic of "whatever that vaso something was".> Or this might be all to discombobulated and we should just go with straight-forward links to hypoglycemia and depression?
> dove (babbling and rambling...)
Dear Dove,You are so cute. Whenever I read your stuff, I can't help but to think how appropriate your "handle" is here.
Oh yeah, your smart too.
:-)
- Scott
Posted by noa on October 27, 2000, at 6:36:39
In reply to Re: vasovagal fainting, posted by danf on October 26, 2000, at 14:42:44
Thanks for all the info, Danf.
Do you know if anything can lower a threshold for getting this vasovagal reaction from something like yawning? For example--hypoglycemia, anemia, certain medications?
My doc seemed to think not, but I wondered if you had any thoughts on this.
Posted by noa on October 27, 2000, at 6:38:17
In reply to Re: vasovagal fainting, posted by danf on October 26, 2000, at 14:42:44
BTW, I read that vasovagal fainting when standing from a lying or sitting position is fairly common in adolescents because of elasticity in blood vessels in the extremities. I did get the greying out from standing up, as a teen, too.
Posted by danf on October 27, 2000, at 11:11:38
In reply to Re: vasovagal fainting, posted by noa on October 27, 2000, at 6:36:39
It is an interesting question.
anaemia & hypoglycemia lower the threshold for fainting, but the mechanism is usually not vasovagal.
For anaemia to have a significant effect, it must be severe & this tends to be a positional /change of position effect where blood flow rates are high from the anaemia & do not compensate. AS in, peripheral vessela are dilated & one stands up & faints... 'orthostatic fainting'
hypoglycemia is similar but is driven by glucose supply to the brain. As blood glucose falls, neurologic function starts to fail, this includes all levels, conscious & autonomic plus the body pumps out adrenaline to keep blood glucose levels up ( the jittery feeling some people get that warns them the glucose level is falling ). Then as glucose stores are used, glucose levels quickly fall & fainting occurs.
Then for meds. since vasovagal is triggered by a cholinergic episode ( heart slowing), any med that increases cholinergic tone has the theoritical potential to lower the threshold for vasovagal fainting ( gagging & retching increases this tone, by the way).
most SSRIs & ADs fall into this catagory. However, they do not in practice, seem to have this side effect.
Many other meds may have fainting as a side effect. beta blockers, High BP meds of all classes, Heart meds, angina meds, etc... however most of these cause fainting by affecting BP control, or peripheral resistance, etc, not by affecting vagal tone.
I know when I started celexa, that I yawned like crazy for a couple of weeks. I also coughed & gagged. there was some light-headed-ness with the coughing /gagging, but never a full faint.
I think it is possible for an AD med to lower the VV threshold, but unless it happenes more than once it will be difficult to trace the cause. Most would consider this to be an idiosyncratic reaction, if present.
Posted by noa on October 27, 2000, at 16:11:55
In reply to Re: vasovagal fainting, posted by danf on October 27, 2000, at 11:11:38
> It is an interesting question.
>
> anaemia & hypoglycemia lower the threshold for fainting, but the mechanism is usually not vasovagal.
>
> For anaemia to have a significant effect, it must be severe & this tends to be a positional /change of position effect where blood flow rates are high from the anaemia & do not compensate. AS in, peripheral vessela are dilated & one stands up & faints... 'orthostatic fainting'
>
> hypoglycemia is similar but is driven by glucose supply to the brain. As blood glucose falls, neurologic function starts to fail, this includes all levels, conscious & autonomic plus the body pumps out adrenaline to keep blood glucose levels up ( the jittery feeling some people get that warns them the glucose level is falling ). Then as glucose stores are used, glucose levels quickly fall & fainting occurs.
>
> Then for meds. since vasovagal is triggered by a cholinergic episode ( heart slowing), any med that increases cholinergic tone has the theoritical potential to lower the threshold for vasovagal fainting ( gagging & retching increases this tone, by the way).
>
> most SSRIs & ADs fall into this catagory. However, they do not in practice, seem to have this side effect.
>
> Many other meds may have fainting as a side effect. beta blockers, High BP meds of all classes, Heart meds, angina meds, etc... however most of these cause fainting by affecting BP control, or peripheral resistance, etc, not by affecting vagal tone.
>
> I know when I started celexa, that I yawned like crazy for a couple of weeks. I also coughed & gagged. there was some light-headed-ness with the coughing /gagging, but never a full faint.
>
> I think it is possible for an AD med to lower the VV threshold, but unless it happenes more than once it will be difficult to trace the cause. Most would consider this to be an idiosyncratic reaction, if present.
Posted by Bugster2k on January 12, 2001, at 12:07:25
In reply to Re: vasovagal fainting--thanks (np) » danf, posted by noa on October 27, 2000, at 16:11:55
I beleive that I have Vasovagal syncope.
The first time I started coughing and fainted
was in the summer of 1994. It comes and goes
and seems to get worse in cold weather.
Throughout the spring and summer, this
may have happened once or twice. Living in
the northeast, this has been a pretty winter
so far. The worst I have had it this winter,
I passed out about 7 times during 1 eight hour
shift at work. It only happens when I cough,
and tessilon pearls, doesn't help that much.> > It is an interesting question.
> >
> > anaemia & hypoglycemia lower the threshold for fainting, but the mechanism is usually not vasovagal.
> >
> > For anaemia to have a significant effect, it must be severe & this tends to be a positional /change of position effect where blood flow rates are high from the anaemia & do not compensate. AS in, peripheral vessela are dilated & one stands up & faints... 'orthostatic fainting'
> >
> > hypoglycemia is similar but is driven by glucose supply to the brain. As blood glucose falls, neurologic function starts to fail, this includes all levels, conscious & autonomic plus the body pumps out adrenaline to keep blood glucose levels up ( the jittery feeling some people get that warns them the glucose level is falling ). Then as glucose stores are used, glucose levels quickly fall & fainting occurs.
> >
> > Then for meds. since vasovagal is triggered by a cholinergic episode ( heart slowing), any med that increases cholinergic tone has the theoritical potential to lower the threshold for vasovagal fainting ( gagging & retching increases this tone, by the way).
> >
> > most SSRIs & ADs fall into this catagory. However, they do not in practice, seem to have this side effect.
> >
> > Many other meds may have fainting as a side effect. beta blockers, High BP meds of all classes, Heart meds, angina meds, etc... however most of these cause fainting by affecting BP control, or peripheral resistance, etc, not by affecting vagal tone.
> >
> > I know when I started celexa, that I yawned like crazy for a couple of weeks. I also coughed & gagged. there was some light-headed-ness with the coughing /gagging, but never a full faint.
> >
> > I think it is possible for an AD med to lower the VV threshold, but unless it happenes more than once it will be difficult to trace the cause. Most would consider this to be an idiosyncratic reaction, if present.
Posted by Noa on January 15, 2001, at 11:30:57
In reply to Re: vasovagal fainting--thanks (np), posted by Bugster2k on January 12, 2001, at 12:07:25
WOW--that is a lot of fainting--it could be very dangerous, don't you think?
As for my fainting--after that one episode, I have not fainted again. And, it seems that since beginning exercise, my circulation must already have improved somewhat, because I don't find myself having to be so vigilant about "gray outs" when I yawn and stretch--they seem to be less pronounced.
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