Try this book especially designed to use yawning to calm down a child and get them to sleep: http://www.sleepymonkeystory.com
Worked on my hyper kids – hope it will yours too!
I know all about this because, as a child, I was extremely hyper-active. My mother refused to put me on the medications the doctor prescribed and toughed it out with me.
Hopefully this can be part of the solution.