my 8 year old son was taking singulair and zyrtec for 6 years. I...

my 8 year old son was taking singulair and zyrtec for 6 years. I forgot to give him his medicine for a couple of days and noticed how mellow he was. I started thinking about it and realized that it might be the medicine. He was 2 when he started taking singulair and zyrtec so i thought this was just how a boy was supposed to act like, i have four daughters too. He has always had trouble in school just barely passing each grade, his teachers all told me to have him tested for adhd and i knew in my heart he did not have that. the last few months have been really bad with his attitude, yelling, wining, hitting his sisters, and talking back to me like i am a piece of crap. I am so glad i forgot to give him his medicine, he does not take anything anymore. I hope that when all the medicine is out of his system he will be even better.