Thankyou!
Well, I would usually just have Claritin (loratadine) nearby because I have had a Tick Anaphylaxis and always need to be prepared. I was told a few weeks ago, when talking about the vaccine reaction, to change this to Telfast 180mg (fexofenadine) which I think may be called Allegra in the US. It's supposed to work faster as well.

I read so much about all the different newer generation antihistamines that it boggled my mind and never did figure out which one would be the best. These are the non-sedating ones mind you. After reading your message I looked into H3 receptors and came across something called Pitolisant that's used to treat narcolepsy. You would understand all the technical papers better than me. I just kept getting confused.

from British Journal of Pharmacology Feb 2020
Histamine, histamine receptors, and neuropathic pain relief

take care there