Zyrtec and side effects of zyrtec

My son was getting in trouble with his new Kindergarten teacher almost every day. He went from being a bright, well behaved little boy to being labeled a troublemaker with learning issues almost overnight. At school he was crying all the time, poked another kid with a pencil, threw something at another child and wouldn't listen to his teacher. He had been in a very structured Pre-K program and we had never had any issues like this with his behavior. During a lengthy conversation with his teacher, she mentioned that he didn't behave this way every day. He actually had some days when he was "very good". I was at the end of my rope. When we asked him why he was doing these things he told us, "My brain told me to and I couldn't stop." Scary thing to hear from your 5 year old. After talking to my mom about the problems, she suggested that I look up the side effects of Zyrtec and I found this site. Many things matched up with what the teacher was telling us. The fact that he had some good days at school makes sense because he was only taking it on the days he needed it for seasonal allergies. Because he took it right before bed and the side effects would wear off by the time we picked him up from school we weren't seeing the full effect of what this medication was doing to him. We haven't given him Zyrtec for over a week and he hasn't gotten in trouble a single time at school! He's been much easier to put to bed at night and much more pleasant to be around in the evenings. We will never give him Zyrtec again and will be MUCH more aware of possible side effects from medicine.

I have wondered about the side effects of zyrtec - our daughter has been taking it for 5 year - the same amount of time she has been depressed, negative, etc and these symptoms just get worse as she grows older! I wish she wasn't taking zyrtec. I don't think it's just a coinincidence that her sadness, gloom, and depression began the same she started the zyrtec. She's only 50 lbs and the Dr has her on an adult dose (but she does have severe, severe allergies).