The problem with driving laws in Australia is that you can have it in your system for days afterwards, even though you maybe quite capable to drive, if you are Random Drug Tested, you can be fined if the drug test proves positive, even with minute amounts in your bloodstream.
Whereas in other jurisdictions like in the USA I believe that a level of impairment is considered. As the article says some other prescription medications can impair your driving but it is not illegal.
So Sleep Apnea patients for IHL-42x in Victoria (once the legislation is past) can be confident to drive even if miniscual amounts are still in your bloodstream.