hi i have this disorder too, idiopathic hypersomnia disorder
my consultant has prescribed 400mg provogil / modafinil per day
200mg in the morning and 200mg at 1pm
so far it has been good although i only take it if i am having a bad day
so far i have had no side effects but i do not intend to stay on these as a permanant solution

if i drive long distances then yes i have to tak them as i can fall alseep behind the wheel of the car.