Relation of histamine to noraderanline and adrenaline..... A little past the middle of the page:
http://nobleboss.awardspace.com/mednotes/pharmanotes/chapter_set4/hist_antihist.htm"After administration of Histamine, it binds with the H1 receptors present in the arterioles and precapillary sphincters and causes vasodilatation. So, there is ↓PR and ↓BP. After sometimes the BP comes to normal as Histamine is metabolized and also diluted by the body fluid. There is a secondary rise in BP caused by adrenaline and noradrenaline which are secreted as a result of stimulation of the nicotinic receptors in the adrenal medulla by Histamine.
If we administer antihistamine, it will block the H1 receptors and there will be no fall of BP but as Histamine will still act on the nicotinic receptors of the adrenal medulla, there will be rise. The rise can be prevented by administration of α-blockers which proves that the rise was due to adrenaline or noradrenaline."
The above would explain why antihistamines dont work with this adrenal surge +allergy issue. It also explains why beta blockers might not work very effectively, but substantial dosages of alpha blockers might. I remember someone mentioning either on this forum or "the other" one, that afluzosin(flomax i think its called), an alpha blocker meant for prostate problems, really helped them out with POIS.
It seems the nicotinic receptors in the adrenal glands might be a key issue here.... Look at Vincent M's post in the "other forum":
Took one pill of diphenhydramine (generic Benadryl) last night about 15min before an "o" and today I felt great. I think I feel the best I have since I got POIS. I may still have some brain fog and I can tell my anxiety is still a bit high, but physically I'd say I'm 90% free of POIS. Mentally I'd say at least 50% free of POIS. I can't tell if benadryl works better than Claritin or not just yet, but it seems it does. Also it's possible that I feel good due to a cumulative effect of the other meds I've been taking. I plan on testing benadryl again next weekend. I don't have as much time to experiment now that I'm working unfortunately
Why does benadryl work before O for him, but claritiin does not?? BEcause benadryl is an anticholingeric, meaning it helps block activation of nicotinic receptors, while claritin really just has antihistamine properties, having no effect on the adrenal glands, like bendaryl does.
If the Adrenal surge theory is correct, and thats a big IF, then it seems there are three ways to prevent alot of the bad POIS symptoms: 1. prevent the conversion of noradrenaline to adrenaline, which can be done with such things as niacin. 2. prevent the release of adrenaline from the adrenal glands, which can be done by blocking the activiation of the nicotinic receptors on the adrenals. and 3. block the activtiation of adrenaline receptors throughout the body with beta blockers(although this seems to be the least effective since its better to prevent the surge rather than try to contain it after the fact).I want to add I put the above solutions in order of effectiveness. Theoritically it would seem best to prevent the conversion in the first place, which niacin does... Second best to prevetn adrealine release which antinicotinics/anticholinergics should do... and lastly try to stop the adrenaline from attaching to receptors all over your body, which seems difficult to do, plus beta blockers have their own side effects. It seems the solution is between the first and second steps, taking something before O to stop noradrenaline conversion or stop release of adrenaline.
I want to add two more things and this is very important: 1. Testosterone needs to be added to the list of above solutions, and it works by making you pee out noradrenaline, essentially lowering the amounts of adrenaline precursor in your body AND 2. If none of these above solutions work for you I would say one of two things is going on: First, you dont have POIS and you have some other issue going on that just gets worse when you orgasm, it could be hypoglycemia it could be an anxiety disorder, etc. and Second: you could have a lingering allergy cascade even after the orgasm, and hence u still have high amounts of histamine goign to ur adrenals and causing chronic hyper adrenaline to mess u up