My 5 year old daughter was started on Zyrtec about 10 days ago (D...

You might want to read some of the side effects of Singulair on this same website, it is a huge source of personality changes.

My daughter (4 years old) has been taking Zyrtec for at least two years every night before bedtime. She was always on the "sad face" at daycare during the summer and prior to summer, so I just attributed it to other influental kids at her daycare. I recently took her off of Zyrtec (about 3 months ago). She started a new school in August, and for the most part, she has gotten smiley faces on her behavior chart....until this past Friday. She got a runny nose, so I gave her Zyrtec again Thurs night. The next day, I noticed that she wasn't listening to me and was in constant motion. She was also hitting furniture, toys, and things when she got mad. She got a sad face on Friday b/c she pushed a child at school. Since Friday (today is Wed) the only day that she has not gotten a sad face was Monday. She got one today for pushing a child down and putting her hands around another child's neck in anger. I tried to think of things that were different and whoa and behold, it's the re-implementation of Zyrtec. I am not going to give it to her anymore, and now I am realizing that part of her problem during the summer was probably the Zyrtec side effects. I'm not one to defend my child's behavior with medication; however, this drastic change over the past few days has convinced me that medication may just be partially or even mostly to blame.

Hi, My 2 and 4 year old started taking Singulair in addition to the Zyrtec they had been taking for months. They started hallucinating ("Mommy, Elmo/Telletubbies" pointing out the window), waking up with terrible nightmares, and having aggressive/hyper behavior. We stopped it and evrything went back to normal. I won't give it to them again and stopped the Zyrtec although have recently reintroduced it back for my 4 year old.