Local Anesthetics

History of Local Anesthetics

Cocaine was the first local anesthetic; Peruvian Indians chewed the Coca leaves and made a bolus of the dried leaves, which they would mix with ashes (called chica). By chewing this, their physical endurance was increased. Cocaine was isolated in 1860 and used clinically as topical anesthetic in Vienna by Karl Choler (spelling?). Freud was a buddy of this Choler fellow, and experimented with cocaine with him. They eventually found that cocaine is highly addictive.

RJ Hall was the first dentist to use cocaine as an anesthetic when he extracted a tooth. It was found that a precise injection of cocaine will produce a nerve block, and that cocaine was a good local anesthetic. It blocks the amine pump in the adrenergic synapses, resulting in a sympathetic response.

Procaine was the first synthetic local anesthetic (1905), followed by Lidocaine (1948), which we obviously still use today.

Agents, Generic (and Brand) Names:

The suffix “-caine” is the official designation for local anesthetics (LA). The LA’s are divided into two classes, esters and amides. (There is only one ketone, which is dyclonine (Dyclone)).

Of the ester class, it is important to know the name and brand name for the following (as found in the handout): Procaine (Novocain, Procaine); tetracaine (Pontocaine, Tetracaine); cocaine; benzocaine, ethyl amino benzoate (Americaine, Anesthesin, Hurricaine, and many others); chloroprocaine (Nesacaine); propoxycaine (Ravocaine).

The amides are “more important for use” so know all of those listed.

Category: Pharmacology Notes