Please watch your child closely on Singulair. My two boys were not the same on the med. Soon after starting to take the med., both became agressive, prone to fits of crying, emotional outbursts. Sone after taking them off the med., they were back to normal. The doctors won't always believe you about medications and your children. However, you are the parent and you know your child. Do what your "gut" is telling you to help your child!