My daughter has been on Singulair, 4mg chewables for almost a yea...

My daughter has been on Singulair, 4mg chewables for almost a year. We have had problems with her aggressive behavior, mostly hitting - her brother and now other children at school. Her teacher and I met today and both were at a loss for her continuous aggressive, impulsive behavior because by every other account she is a sweet, good natured child. We have tried everything - rewards, taking away things of importance to her all to no avail. She says she cannot help it but she is trying her best and I believe her. She is so sad after one of her impulsive episodes. For the heck of it, I thought I would look up Singulair side effects online and cannot believe all the information on side effects in children. My daughter also has been having very vivid nightmares and coming into my bed in the middle of the night. She also has leg cramps and pains in the middle of the night very frequently. I am taking her off the Singulair and pray that I see some positive change in her behavior.