Comparative effects of etidocaine and lidocaine on nerve and neuromuscular conduction in the frog.

The effects of etidocaine and lidocaine were studied on frog nerve and neuromuscular junction. Etidocaine is 10 times more potent than lidocaine in blocking nerve conduction. At pH 6.9, the first peak of the compound action potential is blocked more profoundly than is the second. At pH 7.2 and 7.5, both peaks are blocked to about the same degree. There was a dose-related decrease in miniature endplate potential (mepp) amplitude and acetylcholine sensitivity of the endplate region produced by both drugs. Lidocaine increased the time required for mepp repolarization, while with etidocaine receptor desensitization was observed.