Oh Dear, What Can the Matter Be?

One of my kiddos is out of medicine for his ADHD... that's what the matter "be"!!! He's going to send his teacher to the looney bin if he doesn't get his medicine SOON! However, I will say, that he uses his ADHD to try to get an "advantage" over adults. He thinks he can act out and do whatever he wants to do (hitting, swearing, being a total wreck), then just say "I'm allowed because I don't have my medicine in me". I understand that a child who has ADHD acts differently than a child who doesn't. I get that. But, is it really necessary for all of those other "things" to happen because he's not on his medicine? I've had other kids with ADHD, and when they didn't have their medicine, yes, they were different. But not that drastically different. Can anyone offer me some advice, info on how to deal with him? His own mother tells him that he is able to control himself, and that the medicine doesn't make him stop completely. I don't want to be too hard on him, but he is totally wrecking my class at the same time. I need help here, people!!