ATC Group: N01BA Esters of aminobenzoic acid

Benzocaine is a local anaesthetic of the ester type, acting to produce reversible loss of sensation by preventing or diminishing the generation and transmission of sensory nerve impulses near the site of application. Depolarisation of the neuronal membrane and ion exchange are reversibly inhibited.

Chloroprocaine is procaine in which one of the hydrogens ortho- to the carboxylic acid group is substituted by chlorine. Chloroprocaine, blocks the generation and the conduction of nerve impulses, presumably by increasing the threshold for electrical excitation in the nerve, by slowing the propagation of the nerve impulse and by reducing the rate of rise of the action potential. Chloroprocaine (like cocaine) has the advantage of constricting blood vessels which reduces bleeding, unlike other local anesthetics like lidocaine.

Procaine is a benzoic acid derivative with local anesthetic and antiarrhythmic properties. Procaine binds to and inhibits voltage-gated sodium channels, thereby inhibiting the ionic flux required for the initiation and conduction of impulses. In addition, this agent increases electrical excitation threshold, reduces rate of rise of action potential and slows nerve impulse propagation thereby causing loss of sensation. Procaine is indicated for production of local or regional anesthesia, particularly for oral surgery. Procaine (like cocaine) has the advantage of constricting blood vessels which reduces bleeding, unlike other local anesthetics like lidocaine.

Tetracaine is a local anaesthetic and is believed to act by blocking nerve conduction mainly by inhibiting sodium ion flux across the axon membrane.