Diprenorphine Hydrochloride (brand name Revivon; former developmental code name M5050), also known as diprenorfin, is a non-selective, high-affinity, weak partial agonist of the μ- (MOR), κ- (KOR), and δ-opioid receptor (DOR) (with equal affinity) that is employed in veterinary medicine as an opioid antagonist.