Cocaine selectively blocks sodium channels which is the mechanism that leads to local anesthetic effects.
Voltage gated sodium channels play very important roles in the body as they are responsible for action initiation and propagation in excitable cells, such as nerves, muscles and neuroendocrine cells. Like other sodium ion channels blockers such as lidocaine, Cocaine selectively blocks sodium ion channels which denies entry of sodium ions in the cell, thus leading to local anesthetic effects.