The antinociceptive and antihyperalgesic effect of tapentadol is partially retained in OPRM1 (μ-opioid receptor) knockout mice

► The relative contribution of MOR activation to tapentadol-induced analgesia was determined. ► OPRM1 knockout mice were used. ► Tapentadol show a 10-fold higher potency in chronic neuropathic as compared to acute pain. ► Activation of MOR only partially contributes to the analgesic effect. ► The remaining antinociceptive activity in OPRM1 KO mice was abolished by yohimbine.