OP, please, please, please, I have worked in mental health reseach for 14 year. The side effects of respirol for adults, can be be very problematic. Using a medication like that off label with a child, who brain is still developing, has been untested. In other words there is no research, that has even looked the effects. You have no recourse if something goes wrong.
If you feel that you no choice. Please get a second opinion, with a physician that is hooked into a hospital, so they can monitor you child's blood work more carefully. That fact that stimulates haven't work, some psychiatrist opt for goong in a differnt direction and try Wellbutrin, which is med that people use to receive for ADHD.
Check Georgetown psychiatry or another hospital, where doctors can discuss cases with with their colleagues and again blood work can be monitor. Using Rispidol on a child is that serious.
Good luck!