腎上腺素可以加強第一類抗心率不整藥物之皮下止痛效果

Epinephrine enhances the cutaneous analgesic effect of class I antiarrhythmic drugs

腎上腺素因具血管收縮的特性，常會與局部麻醉藥合併使用以延長局部麻醉藥藥效。我們先前的研究發現第一類抗心率不整藥物具有局部麻醉的效果，本研究則是運用大白鼠皮下注射方式，進一步研究併用腎上腺素，是否也可以加強第一類抗心率不整藥物的反下止痛療效。我們觀察了三個第一類抗心率不整藥物（IA：奎尼丁：IB：脈律定及IC：氣卡胺）與兩個傳統局部麻醉藥（鹽酸布比卡因與利多卡因），發現腎上腺素的合併使用不僅僅可以有意義地增加第一類抗心率不整藥物的麻醉藥效（最大可能效果百分率），也可以延長作用時間（p<0.05）。我們的結論是：腎上腺素的合併使用，可以加強與延長第一類抗心率不整藥物的皮下止痛效果。

For prolongating the local anesthetic effect, epinephrine, a vasoconstrictor, is commonly injected subcutaneously in combination with local anesthetics. In our previous report, the class I antiarrhythmic drugs were found to have a local anesthetic effect on cutaneous analgesia. The aim of the study was to evaluate whether the adding of epinephrine could enhance the cutaneous analgesic effect of the class I antiarrhythmic drugs. Using a subcutaneous infiltrative method in rats, the influences of epinephrine on drugs' effect were evaluated. Three class I antiarrhythmic drugs (IA: quinidine; IB: mexiletine and IC: flecainide) and two local anesthetics (bupivacaine and lidocaine) were used. We found that the combination use of epinephrine could significantly increase not only the efficacies (% maximal possible effects) but also durations (durations of complete recovery) of cutaneous analgesia of the class I antiarrhythmic drugs (p < 0.05 for each comparison). In conclusion, the adding of epinephrine to the class I antiarrhythmic drugs could produce an enhancement of their cutaneous analgesic efficacies and durations after subcutaneous injection.