(2) Antagonist drugs may be administered for diagnosis of addiction by a registered nurse at an approved site when the nurse has completed required training and a physician or naturopathic physician is available on call. Antagonist drugs shall not be administered without informed written consent of the person. [1977 c.871 §22; 1979 c.744 §28; 2009 c.595 §502; 2017 c.356 §56]