The present study investigated whether a co-application of tramadol (TRA) and dihydroetorphine (DHE) would exert a synergy in analgesic effect and delay acute tolerance development.

• 本文旨在研究曲马朵(tramadol,TRA)和二氢埃托啡(dihydroetorphine,DHE)联合用药是否可产生协同镇痛并延缓耐受的发生。