HELP! | ADHD Information

My son recently was diagnosed with ADHD, I never thought that I would be giving him medicine but I had to he was about to get kicked out of school, we tried stratera 18 and 25 mg neither one of them worked. So now he is on concerta 27 mg I am not really sure how long it is suppose to take to kick into his system so to speak,does anyone know, I know he did not have a good day at school  today, the teahcer said he was stil hyper. My son is ADD and has been on Concerta 36mg for a year. It has not stunted his growth or suppressed his appetite. He concentrates better but does have trouble sleeping if he doesn't take it by 7am. He has hit a growth spurt since Christmas and the doc is wanting to up his dose to 54 mg. I am worried myself, but it is time released. It doesn't just hit their system all at once. It only took a week to see if it was working. If no improvement, I would call the doc.