丁卡因 (阿美索卡因)
**丁卡因**（又稱**阿美索卡因**）是一種局部麻醉劑，主要用於眼表（角膜和結膜囊）的局部麻醉。 > **臨床提示：** 由於其刺激性及點藥時的疼痛感高於丙美卡因 (proxymetacaine) 等替代藥物，在小動物臨床中較少使用。由於具有嚴重的角膜毒性，絕不能作為居家治療藥物開立。
作用機制: Local anaesthetic action is dependent on the reversible blockade of the **voltage-gated sodium channels** → prevents the influx of sodium → inhibits the propagation of an action potential along the nerve fibre. Sensory nerve fibres are blocked before motor nerve fibres, allowing a selective sensory blockade at low doses.
各物種劑量
- Local anaesthesia of the ocular surface · 1 drop per eye · topical · single application · single dose · Uncommonly used; proxymetacaine is advised as an alternative.
- Local anaesthesia of the ocular surface · 1 drop per eye · topical · single application · single dose · Uncommonly used; proxymetacaine is advised as an alternative.
劑量為合格獸醫專業人員的臨床參考。請務必對照最新藥品仿單及個別病患確認。
給藥途徑
禁忌症
- Therapeutic use (repeated administration for pain relief)
- Application prior to a Schirmer tear test
不良反應
- Marked conjunctival irritation
- Chemosis
- Pain on application
- Corneal epithelial toxicity
- Delayed healing of corneal ulcers
監測
- Corneal integrity (fluorescein staining if corneal damage is suspected)
過量
Overdosage in a clinical setting typically presents as local toxicity rather than systemic effects. Repeated administration leads to severe **corneal epithelial toxicity**, delayed healing of corneal ulcers, and potential corneal melting. > **Do not use for therapeutic purposes.**
VetSheet 藥物參考供持牌獸醫專業人員作臨床決策輔助之用,不能取代專業判斷或廠方最新藥品說明書。