anaesthetics Flashcards Preview

pharmacology > anaesthetics > Flashcards

Flashcards in anaesthetics Deck (6)
Loading flashcards...

structure of a local anaesthetic

aromatic region + ester/amide bond: amide bonds have longer half lives and are more widely distributed


MOA of local anaesthetics

are weak bases, ionised form blocks Na+ channels, act on inner part, block nerve conduction in order of C fibre, A delta, A beta, A alpha


what rapidly hydrolyses ester type local anaesthetics?



what hydrolyses amide type local anaesthetics?

liver microsomal P450 enzyme


Why are adrenaline and felypressin (non catecholamine) used with local anaesthetics?

vasoconstrictors, temporarily limit the spread of the local anaesthetic into systemic circulation


ADRs of local anaesthetics?

CNS - dose-dependent: depression, excitation
- restlessness, shivering, tongue numbness/metallic taste
- CNS depression/convulsions (depression of cortical inhibitory pathways)
- respiratory depression
CV: - myocardial depression/conduction block
- vasodilation
- pronounced fall in BP and death