Ok, I understand your plight but I once read that about 95% of air incidents happen either on take off or landing so you only really need to be asleep for these
as the chances of anything happening inbetween is so remote it doesn't stack up.
Sorry, only trying to help with statistics - IMHO much better than dopeing yourself up for a flight besides if you were so unlucky and anything happened during the flight you would be so far out of it that you couldn't cope.