As a matter of interest, I spent 16 years in Transport Command and 24 hour duties were not unknown.
In fact, on the Belfast, we could do 42 hours with a double crew (we had a 6-bunk bedroom downstairs).
In those days, the RAF aviation medics were pushing Mogadon.
I never tried one for I was a great believer in getting the cr*p out of the way and then getting into the nearest bar when it was over.
Does Mogadon still exist and is it approved?