Lidocaine, Carbamazepine, and Imipramine Have Partially Overlapping Binding Sites and Additive Inhibitory Effect on Neuronal Na+Channels

Abstract

Carbamazepine, lidocaine, and imipramine bind to a common site with the common aromatic motif. External to the aromatic site, there is another weaker and less gating-dependent site for the tertiary amine chain in the latter two drugs. Concomitant clinical use of these drugs, thus, should have at most a simple additive but not a synergistic inhibitory action on Na currents.