Naloxone for opioid receptor acts as:: (A) Pure agonist, (B) Pure antagonist, (C) Paial agonist, (D) Agonist antagonist
Answer is B. Naloxone is a pure antagonist and is preferred over older weak agonist-antagonist agents that had been used primarily as antagonists, eg, nalorphine and levallorphan. Ref: Katzung, 11th edition, Chapter 31.