Its a compound unknown to your body. Some compounds wont have such a response, but some will. If you aren't having a major side effect reaction, I don't understand the problem. Drugs effect all differently. Especially considering all the variables involved with transaction from substance to effect.
Ketamine has had annoying effects from repeated use involving my nostril region, I'll admit, but I do tend to binge on k (internasal)
I'm in the same boat pal. Every morning after having K the night before, my nose will constantly run and I keep having to run to the toilet and blow my nose. It's so frustrating at work lol.