4 among various agonists ( morphine , methadone and etorphine ) , antagonists ( naloxone , naltrexone and diprenorphine ) and mixed agonist-antagonists ( pentazocine , butorphanol and buprenorphine ) , buprenorphine is the most potent and the longest acting drug in preventing precipitated abstinence in mice , rats and dogs .
C0027358
naloxone
C0027360
naltrexone