maggiso it wasn't me that had the bad reaction to antimuscarinics, but now you come to mention it, my parents used dish out Kwells for the ferry crossing every summer and I would always go dizzy and throw up afterward. I hadn't even remembered that until I read your post.
I now take Stugeron (Cinnarizine), which is essentially an anti-histamine, purely because that's the only thing the pharmacist in Ireland would give us for dd when she was under 5 and we went to by travel sickness pills. Because we had dd with us she refused to sell us any normal travel sickness pills, so we all took Stugeron and having discovered it's much better at the job, we've stuck with it ever since. I used to spend every ferry trip lying down with my pillow and blanket, now I walk around, go to the shop, do some colouring - even eat. It's been a real revelation.
Having just done a bit of quick research it actually makes a lot of sense that I actually feel quite well having take them, whereas they make other people drowsy.
First of all, considering I have regular flushing episodes as an AD symptom, I'm now wondering if it has anything to do with a degree of possible mast-cell involvement, which the Cinnarizine/anti-histamine might potentially be dampening. Certainly food for thought.
The other active ingredient in Stugeron is Dimenhydrinate (DRAMAMINE) and I just found the following information on that drug.
Dimenhydrinate blocks certain actions of histamine, as well as certain actions of acetylcholine, in the body.
So again, the anti-histamine effect, but what really caught my eye was:
Acetylcholine has functions both in the peripheral nervous system (PNS) and in the central nervous system (CNS) as a neuromodulator. In the peripheral nervous system, acetylcholine activates muscles, and is a major neurotransmitter in the autonomic nervous system.
Even more interestingly:
Direct Vascular Effects of Acetycholine
Acetylcholine in the serum exerts a direct effect on vascular tone by binding to Muscarinic receptors present on vascular endothelium. These cells respond by increasing production of Nitrous Oxide, which signals the surrounding smooth muscle to relax, leading to vasodilation.
Soooo, is it possible that by blocking Acetylcholine the Dimenhydrinate in Stugeron is both having a calming effect on my ANS and reducing vasodilation - hence me feeling better than usual?
I am very foggy on it really, but also, does that last quote imply that reducing/blocking Acetylcholine would also have the effect of freeing Muscarinic receptors - so in effect, the opposite of what anti-muscarinics do? Or am I so brain fogged I've got that completely wrong?
I am probably waaay off the mark, not least of all because I am not in a good way at all this week and my brain is refusing to work with me. But this is what I love about these threads, sharing experience can really help us all to connect the dots, where previously nothing seemed to make sense or perhaps things seemed completely unconnected.