pain management with controlled release local anesthetics

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K08847
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 55050:Anesthesiology-related
• Research Institution: Gunma University
• Principal Investigator: Tobe Masaru 群馬大学, 医学部附属病院, 講師 (90400770)
• Co-Investigator(Kenkyū-buntansha): 小杉 謙介 朝日大学, 歯学部, 講師 (00650780) ; 須藤 貴史 群馬大学, 医学部附属病院, 講師 (60739621)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 局所麻酔薬 / 生体内分解材料 / 徐放薬 / 温度応答性 / 術後痛

Outline of Final Research Achievements

Controlled-release levobupivacaine released 50% of its content within 12 h and 60% within 24 h in the in vitro release study. The withdrawal threshold was higher in the controlled-release levobupivacaine group than in the levobupivacaine group at 6 and 12 h after paw incision. Motor impairment was detected in the levobupivacaine group at 1 and 2 h after injection, whereas no motor impairment was observed 2 h after controlled-release levobupivacaine injection. On histopathology, signs of inflammation were weakly detected in rat muscle and nerve tissues in the controlled-release levobupivacaine group.
A single injection of controlled-releasing levobupivacaine safely inhibited hyperalgesia for 12 h in a rat model. Controlled-release local anesthetics are promising for the management of postoperative pain.

Free Research Field

麻酔

Academic Significance and Societal Importance of the Research Achievements

術後疼痛管理は周術期管理の中でも非常に重要な要素で現在の医療においても充分とは言えない。副作用が少なく確実な長時間鎮痛は非常に重要なテーマである。アメリカのFDAにおいてブピバカイン徐放薬が承認されて10年間程度経過するが日本では臨床使用できないうえに欧米においてもそれほど広まっていない。薬剤として心毒性が強いなど使いにくい要素もあり別の薬剤の開発が待たれていた。今回注射可能でかつブピバカインより毒性の低いレボブピバカインを用いて徐放薬を作成できたことは今後の周術期管理において非常に有用となるかもしれない。