Is this my child?

My 3.5 year old son has inherited my terrible seasonal allergies, confirmed by testing. He has a runny nose, sore throat, red eyes and has been sneezing for the last two weeks. We finally stated him on zyrtec for kids two days ago.

Since then he has been a little crazy. He has been disobeying, throwing temper tantrums, hitting and scratching me. To be fair, I prefer natural remedies in general. I feed the kids local raw honey once they turn one and keep them outside to expose them to allergens to help build up their immunity, etc. I’m not sure if I’m unfairly blaming the medication for a rough period with a three year old. I plan to take him off it tomorrow and see if his behavior changes, but he is miserable (as I am) because of allergies to pollens, grasses, trees and weeds. A google search revealed some moms that said the medication affected their kids’ behavior.

Has anyone else experience behavior changes due to medication? How do you know? Is it just trial and error until you find the right medication?