My 8 yr old son has had tics from his adhd meds before. It is common with the adhd meds. They usually happen when they first start the medicine and last for a week or two and fade to a complete stop in my experience anyways. You could mention it to his doctor but they will probably say the same thing my sons doctor said, that its common and will go away with time. My son is now on a patch for his adhd. Its the best so far. It has worked the longest with very little side effects. I also like it because it is placed on the skin on the lower abdomen and it goes straight to the blood stream and then to the brain. It doesn't have to go to the stomach and then to the liver and be broke down. Its called Daytrana.

I forgot to mention the tics my son had when he was on other meds. He was started on vyvanse then switched to metadate and then to the daytrana patch he is on now. The different tics he has had are
1. snapping his fingers constantly
2. making a snapping sound with his mouth/tongue repeatedly
3. doing this weird thing with his hands balling them up and then stretching his fingers a lot
4. non stop whistling
5. cheek chewing
Those aren't in the order he had them I cant remember which one was first just that those are all the tics he has had.