Being unpremedicated applies to a number of other things than those that involve pain.
Somebody who is pulled over for suspected DUI but who is stone cold sober is unpremedicated.
Likewise, somebody who drinks a lot of vinegar to avoid having a drug test show positive for cannabis is attempting to be unpremedicated.
Dave the driver: I am the unpremedicated designated.
Sam the Sham: Oh, man, that sucks. Wanna sandwich?
Dave the driver: Get me another iced tea, bubba.