on the RLS site I'm still exploring:

http://www.rlshelp.org/rlscomp45.htm#Coenzyme%20Q-10

The tremors persisted following termination of the drug. Trying to help her with the tremors, I started her on coenzyme Q-10, 100 mg am & pm. To our surprise, it didn't seem to help the tremors, but it did two other things: It largely relieved the peripheral neuropathy and it greatly diminished the severity of RLS, frequency of severe sessions of RLS, and dependence on codeine, her drug of choice.