aderall and strattera | ADHD Information

I am new to this site.  My son was diagnosed with ADHD when he was 5, he is now 7.  My question is my son has been on strattera for 2 yrs of course they have increased the dosage as he is getting older but lately it is not working, the doctor put him on aderall.  It seems as though he is getting worse instead of better.  He was getting in trouble at school, now the teacher is calling us and when i go to pick him up she is coming to the vehicle asking me what they are going to do about him.  He has never been violent with me, my husband, or his younger brother, but he drew back to hit me the other day.  What is going on????  Someone please help!!!!!   Any suggestions??