There's several threads sharp. I don't think it's on the prohibited list, but it is a drug that can make you sleepy. A DOT medical doctor would have the final say.
Then you have to worry about the trucking companies insurance which dictate alot of things. If you got in a wreck, that would be a huge plus for the prosecutor. For that reason, the insurance company might deny you.
It's best to stay away from stuff like that when driving a 40 ton vehicle around the public.