Lidocaine

Lidocaine is a lipid-soluble anesthetic that can be used as a pain killer. It tweaks signal transmission in neurons by extending the inactivation of the voltage-gated sodium channels in the neuronal cell membrane responsible for action potential propagation. When this occurs in nociceptors, the sensation of pain decreases.

However, due to its lipid-soluble nature, it can also inhibit the propagation of action potentials in other transmitting cells, such as motor neurons, which results in a typical feeling of numbness in the body.