Local Anesthetic Agents: Classification and Properties

Study Notes

Local Anesthetic Agents

Classification

Esters:
- Procaine (Novocain)
- Tetracaine (Amethocaine)
- Benzocaine
- Chloroprocaine
Amides:
- Lidocaine (Xylocaine)
- Mepivacaine (Carbocaine)
- Prilocaine (Citanest)
- Bupivacaine (Marcaine)
- Ropivacaine (Naropin)

Mechanism of Action

Block the generation and propagation of nerve impulses by:
- Inhibiting the sodium channel
- Reducing the influx of sodium ions
- Decreasing the excitability of the nerve

Properties

Potency: The ability to produce anesthesia
Duration: The length of time the anesthetic remains effective
Onset: The time it takes for the anesthetic to take effect
Diffusion: The ability of the anesthetic to spread through tissue

Effects on Nerve Fibers

A-delta fibers: First affected, responsible for sharp pain and temperature sensation
A-beta fibers: Affected next, responsible for touch and pressure sensation
C fibers: Last affected, responsible for dull pain and temperature sensation

Clinical Considerations

Dose: The amount of anesthetic required to produce anesthesia
Concentration: The strength of the anesthetic solution
Volume: The amount of anesthetic solution used
Speed of injection: Affects the onset and quality of anesthesia

Description

Learn about the different types of local anesthetic agents, their mechanism of action, properties, and effects on nerve fibers. Test your knowledge on the classification, potency, duration, and clinical considerations of local anesthetics.