The effect of intravenous lidocaine, tocainide, and mexiletine on spontaneously active fibers originating in rat sciatic neuromas

Abstract

Te. Lidocaine and tocainide given in incremental doses of 5, 10, 15, 20 and up to 25 mg/kg caused nearly all observed SAFs to stop firing. Mexiletine given in doses of 3, 5, 7, 10 and up to 15 mg/kg showed similar results at lower doses. All agents decreased the sensitivity of SAF to mechanical stimulation. No conduction blockade occurred at these doses of intravenously administered local anesthetics. The demonstrated reduction in firing rate of SAF may explain the pain relief observed in clinical trials of these orally available agents. Correspondence to: Charles Chabal, M.D., Anesthesiology Service, 112A, Veterans Administration Medical Center, 1660 South Columbian Way, Seattle, WA 98108, U.S.A. Submitted September 27, 1988; accepted April 11, 1989. © Lippincott-Raven Publishers....