Naphazoline and oxymetazoline are superior to epinephrine in enhancing the cutaneous analgesia of lidocaine in rats

摘要

Abstract This study observed the cutaneous analgesic effect of adrenergic agonists when combined with lidocaine. We aimed at the usefulness of four adrenergic agonists and epinephrine as analgesics or as tools to prolong the effect of local anesthetics using a model of cutaneous trunci muscle reflex (pinprick pain) in rats. We showed that subcutaneous four adrenergic agonists and epinephrine, as well as the local anesthetic bupivacaine and lidocaine, developed a concentration‐dependent cutaneous analgesia. The rank order of the efficacy of different compounds (ED50; median effective dose) was epinephrine [0.013 (0.012–0.014)?μmol]?>?oxymetazoline [0.25 (0.22–0.28) μmol]?>?naphazoline [0.42 (0.34–0.53)?μmol]?=?bupivacaine [0.43 (0.37–0.50) μmol]?>?xylometazoline [1.34 (1.25–1.45)?μmol]?>?lidocaine [5.86 (5.11–6.72) μmol]?>?tetrahydrozoline [6.76 (6.21–7.36)?μmol]. The duration of full recovery caused by tetrahydrozoline, oxymetazoline, or xylometazoline was greater (P?