LA’s

Question 1

How do LA’s work?

Answer 1

Act by blocking neuronal sodium channels and therefore blocking pain sensation conduction

Weak bases
- lower PKA = more unionised at 7.4
- unionised crosses channels into cell
- become ionised and blocks from na channels from inside neuronal membrane
- stabilises membrane and prevents further AP’s
- bind more avidly to inactivated or open, therefore will preferentially block rapidly firing neurones e.g. pain and sensation nerves over motor (state dependent blockade)