My 15 Year Old Son Has ADHD And Takes His

My 15 year old son has ADHD and takes his meds for this daily. He didn't miss a dose this week, and periodically for the past 5 years, he has been known to talk to much in class. Talkative, loud, and can't stop talking in class. Is this behavioral in his ADHD or can this be controlled by him? Should he get help for this ongoing problem. I am mom and starting to get teacher emails on his talkative behavior.