<prompt> Opioid agonist-antagonist is :PethidinePantazocineBuprenorphineMethadone  <response>: Ans. is b Pentazocine Opioid Agonist Antagonists Not used as analgesic - Nalorphine levallorphan Used as analgesic - Pentazocine NalbuphinePure Opioid Antagonists :NaloxoneNaltrexonePartial weak agonistsBuprenorphineButorphanol 