Local anaesthesia

Question 1

MOA of LA

Answer 1

LAs provide anaesthesia by inhibiting excitation of nerve endings by binding reversibly to and inactivating sodium channels. The hydrophobic, non-ionised form of LA crosses the cell membrane and binds near the intracellular end of sodium channels, increasing the threshold for excitation. This stabilises the sodium channel in its inactive form.

Question 2

What are the ester-type LAs

Answer 2

1. Procaine (short-acting)
2. Tetracaine
3. Cocaine
4. Chloroprocaines

Question 3

What are the amide-type LAs:

Answer 3

1. Lidocaine (medium-acting)
2. Prilocaine
3. Mepivacaine
4. Bupivacaine (long-acting)
5. Etidocaine