Differences in CNS effects of local anesthetics are attributable to several factors84:

• potency
• systemic rate of absorption from the site of injection
• speed of passage through the blood-brain barrier
• rate of biotransformation
• speed of intravascular injection of the anesthetic

CNS stimulation with some local anesthetics may result from selective depression of inhibitory neurons. Rapid administration or large doses can depress all neuronal activity with no CNS signs of stimulation or only transient signs.85

Adapted from: Najjar S, Devinsky O, Rosenberg AD, et al. Procedures in epilepsy patients. In: Ettinger AB and Devinsky O, eds. Managing epilepsy and co-existing disorders. Boston: Butterworth-Heinemann; 2002;499–513.
With permission from Elsevier (www.elsevier.com).
Reviewed and revised April 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.