I've tried triazolam once but for whatever reason it didn't work. So I was left in a sort of drowsy state for the rest of the flight. Personally I wouldn't recommend taking anything you don't normally take.
My biggest mistake by far was eating in the lounge about 2 hours before my flight. Then having a 4 course meal onboard and immediately trying to sleep. My heart was pounding and i felt uncuncomfortably full till morning.
Better to eat too little and get a mid flight snack than be too full in my opinion