We here at 'Fudgethenumbers Towers' are very excited by this new development.
We are currently in beta test of the 'sleep prevention optimisation' study.
In a cost benefit exercise the best return on investment is to give only 1 crew member the drug, (it's very expensive stuff folks). The designated pill popper is the relieved of all duties and merely has to wander the cabin and flight deck slapping the other crew in turn to achieve satisfactory wakefulness.
This gives us 100% success with the minimum of expense.