Principals office symptoms and conditions

My son is almost 4 but has been on Singulair since he turned 3. We saw an immediate improvement in his allergies and asthma and thought it was a miracle drug. That is until we started to see our sweet, outgoing little boy change into something we barely recognized. We thought maybe it was just a stage he was going through or something and didn't connect it to the Singulair until his doctor accidentally wrote his refill prescription for 5 mg. instead of 4 mg. After about 2 weeks on the 5 mg. his mood swings increased substantially. He cried for hours everyday at school. He had previous trouble with his emotions at school on the 4 mg. as well. He continued to cry and throw fits at his preschool so often that he was ending up in the principals office. At home, he became clingy and so emotional that he would cry about everything. After doing some research on Singulair, I immediately took him off the drug. Within 1 1/2 weeks off of the drug, my little boy was a different child. I thought maybe I was the only one who had noticed until his teacher came to the car and ask what happened. She said that he didn't even resemble the same child that started school. He is sweet, and calm. He can take discipline without crying and gets praise every day instead of going to the principals office. His trouble sitting still and listening to the teacher are gone and her push for us to have him tested for ADHD has ended. He is now a star student. The only difference is the removal of Singulair from his little body.