When somebody goes to the dentist and he pulls a tooth without anesthetic, the person is said to be unpremedicated.

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.