estimates of the doses required to occupy 50 % of the mu sites in vivo established the following potency rank order : diprenorphine , naloxone , buprenorphine , etorphine , levallorphan , cyclazocine , sufentanil , nalorphine , ethylketocyclazocine , ketocyclazocine , pentazocine , morphine .
C0010526
cyclazocine
C0079314
ethylketocyclazocine