help

i have a 7 year old step son who was diagnost adhd a couple of years ago. when i first met his father he was taken aderol (adderall) which seemed not to help. he was doing poorly in school, would not listen to any adult, constent trouble and would blame anyone but himself. well we took him back to the psycologist and he changed his med to stratera (Strattera) and clonadine. he was doing great and all of the sudden about a month ago he is back to doing poor in school, not minding arguing with others. im not sure what else to do. could you  please help. thanks so much.