LOCAL ANESTHETICS

LOCAL ANESTHETICS

Local anaesthetics are drugs which, when applied directly to peripheral nervous tissue, block nerve conduction and abolish all sensations in the part supplied by the nerve. (They are generally applied to somatic nerves and act on axons, cell body, dendrites, and synapses. These agents are applied topically or by localized injection in dental and surgical procedures to prevent pain.

A local anaesthetic should not be irritant, toxic, unstable and painful. It should produce anaesthesia without causing the damage of nerve cells. The duration of anaesthetic effect should be sufficient for carrying out the operation. It should besterilized without difficulty.

urface or topical anaesthetics act by blocking the sensory nerve endings in the skin or mucous membranes. The drug should possess high penetration power Local or infiltration anaesthesia is produced by injection directly into the required part to be operated in small amounts.

Local anaesthetics are natural agents (e.g. cocaine), synthetic nitrogenous compounds (e.g. procaine, benzocaine, lidocaine, cinchocaine), synthetic non-nitrogenous compounds (e.g. benzyl alcohol, propanediol) and miscellaneous drugs with local action (e.g. clove oil, phenol, chlorpromazine, etc.