local anaesthetics

Question 1

What do local anesthetics do?

Answer 1

Reversibly block nerve conduction when applied to a restricted area of the body to enable a procedure to be carried out without loss of consciousness

Question 2

Why do we block nerve conduction?

Answer 2

• To prevent pain
• Brain does not process nociception

Question 3

What is nocception?

Answer 3

Process of detecting and transmitting noxious (harmful or damaging) stimuli, involving nociceptors responding to signals that are sent to the brain that can be processed as pain.

Question 4

Historically…

Answer 4

• Carl Koller worked with cocaine
• Over years a less dangerous drug (procaine) was developed

Question 5

What is the general chemical nature of local anaesthetics?

Answer 5

• Aromatic ring, linkage, amine group

Question 6

Note the chemical nature of anaesthetics regarding their ionisation state which is determined by pH, if they are weak bases, etc

Answer 6

Question 8

Note what factors affect the effectiveness of anaesthetics, such as permeability, opening of ion channels, routes of administration, width of axon

Question 9

Check the unwanted effects due to non-specificity AND SPECIFIC non-wanted effects (eg, binding to the wrong voltage gated sodium channels)

Answer 10