My 4 yr old son has been on Singulair for a little over a month.....

My 4 yr old son has been on Singulair for a little over a month...prescribed after asthma attack and severe allergies. He has been a different child, extremely aggressive, out-of-control, and very hyper. I am so tired of having to get on to him constantly, and am realizing he has no control over his behavior. In addition, he just suffered another round of illness, this time also had an ear infection. Now I'm reading respiratory and ear infections are also side effects, how crazy is that?! We are stopping Singulair TODAY...I feel so bad for keeping my child on this medicine at all!!