My daughter is 4 years old and has been on Singulair for asthma f...

My daughter is 4 years old and has been on Singulair for asthma for 1 to 1 1/2 years, with a break during the summer months. Her symptoms have been progressive. Starting first (and almost immediately) with inability to go to sleep at night, then waking up multiple times per night with bad dreams, next itching all over and stomach aches, and now increasingly aggressive/bullying behavior. She is normally a bright, outgoing child, but her outgoing nature has turned more and more destructive and aggressive. Last night she kicked her twin brother in the face. (No, he wasn't hurt) Her daycare teachers have complained over the last three months that she's bullying others and sometimes intentionally throwing things at others. Now it has progressed that she's out and out refusing to do things when she's told by her teachers (basic things like get a plate, sit down, and each lunch). She rolls her eyes when given instructions and is not looking people in the face. Toys seem to break "by accident" with her much more than either of her two siblings. At home she has made our family life miserable a lot of the time. Discipline seems to do no good. She says she doesn't know why she does these mean things and does not learn from her mistakes. She's starting to see herself as a "bad girl" and shame on me, so was I, until we started wondering about the Singulair. Be warned, for us it all added up over time. With kids this age you tend to assume it's just part of their growing independence, but we finally realized this isn't normal. We stopped her Singulair last night and are waiting to see if there's a change in her behavior. Thanks to all the parents that have written in.