I recently got my hands on a first generation antihistamine (dexchlorpheniramine, it is very hard to find older antihistamines here in india, pharmacies don’t stock it), I straightaway noticed an effect on my dizziness, which reduced to tolerable labels. I want to try benadryl(diphenhydramine) next, but I cannot find that in the market here.
The effect antihistamines have on me are complex, with some antihistamines exacerbating the dizziness, and some lessening the dizziness.
Antihistamines which increase the dizziness-
pheniramine
promethazine
Antihistamines which reduce the dizziness-
dexchlorpheniramine
diphenhydramine
cyproheptadine(severe side effects but dizziness reduces)
Antihistamines which have no effect-
meclizine
Second generation antihistamines(which do not cross the brain) usually have no effect on my dizziness/vertigo, like cetirizine.
An interesting point I noticed that the antihistamines which reduced my dizziness/vertigo have strong to very strong anticholinergic effects, besides the histamine blocking action.
Important notes if you want to go this way-
Usage of anticholinergic medications has been associated with increased chances of developing dementia later in life.
Second is considerable sedation with these drugs, (they parse blood brain barrier and block the histamine receptors in the brain also leading to sedation)