I have a couple of kids like that. One thing that helped was a post it note on my fridge. I started doing it with my daughter when she was that age. It said:
Has she had enough...
Exercise?
Protein?
Vitamins?
Water?
Attention?
Love?
I have found that most times I can remember at least one that is lacking for the day and it helps get the behavior back on track. A deficiency of any of those will lead to hyperactivity, acting out, etc.
I have love and attention separate because they are two different needs. Kids need attention-- someone actually spending time with them, listening, playing with them, etc. and love-- which can be a quick hug, a joke in a lunch box, telling them we love them, even a wink and a smile across the room. The more my kids get of all of the above, the better they act. Exercise can be a biggie in winter too, when kids don't get very much time outside.
You might also want to get some DHA/Omega 3 supplements. Most kids are deficient these days and they are needed for proper brain function. Some recent studies have suggested that most kids with ADHD-like behavior are deficient in Omega 3 oils. You can also use flax oil. My kids love Nordic Naturals DHA supplements though (strawberry).
Some kids with hyperactivity also benefit from epsom salt baths. Put a couple of cups in a warm bath and let them soak. That also works well for a lot of kids with Autism Spectrum Disorders and other behavior issues. You can google it for more info.
You could also check out the book _Is This Your Child?_ by Doris Rapp if you suspect food sensitivities. Some kids (about 5%) get hyper from food coloring and others react to preservatives, artificial flavors and so on. My daughter reacts to pesticides on non-organic fruits and veggies, some dyes, and dark chocolate. The book can help you figure out if anything like that could be the case.
Good luck!