Find out from his teacher if he starts out the day ok, but then begans to lose it after a few hours. That would mean the meds are wearing off. M has a max duration of 4 hours. If he starts out bouncy and fidgety, then the dose is too low and not affecting him.
V is a very long lasting med, so I can understand the doc doing this. It also saves the embarrassment or hassle of the child taking the med at school.
Hope this helps.
Sorry I didn't specify which medicine he is on currently it's methylphenidate which he takes twice a day. He is in kindergarten and his teacher sent a note home saying that he is more talkative and fidgety then before, I talked to his pediatrician and he wants to put him on vyvanse when he turns 6 which is in a couple months
Not knowing which med he was on makes this harder to answer. All meds only last for a certain time frame. That time frame can be from 3 to as long as 12 or more hours for a med like Vyvanse.
So when you say the medicine is not working, I don't know if you mean at all or just that it is not working as long. If he is in school, have they reported any difference in him? If its just that the meds are not acting long enough, that can be a fairly easy fix by his doctor.
In terms of being disrespectful, that kinda of comes with the age and exposure to other kids (if he is at school). The sudden bursts of anger are more concerning as that could be due to anxiety or frustration - which are typical for children with ADHD.
So, besides talking to your doctor about his meds - I think that it really is also very important to get more information about ADHD and how to help your child. My suggestions are to buy the book (only about $10 on Amazon) - "The ADD/ ADHD Answer book," by Susan Ashley. Also check out http://www.additudemag.com/topic/parenting-adhd-children/parenting-tips.html
go the sub section Parenting Skills under Parenting ADHD Children
Hope this helps. Best wishes.