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M3 Pain and Pain Management > Pharmocology > Flashcards

Flashcards in Pharmocology Deck (18)
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1

What is an LA cartridge?

anaesthetic agent, vasoconstrictor, preservative/stabiliser, isotonic carrier medium,

2

Name 3 UK trade names for lidocaine and adrenaline

Utilycaine, Lignospan Special, Xylocaine

3

Name 2 UK trade names for articaine and adrenaline

Bartinest and Septanest

4

Describe the structure of LA

Lipophilic part, intermediate chain, hydrophilic

5

What are the 2 different types of molecular structures within the intermediate chain?

Ester and Amide

6

What is the main action of a local anaesthetic?

REVERSIBLY blocky sodium channel so that action potentials cannot occur along the nerve

7

What are the 2 theories for how local anaesthetics work?

Specific receptor theory
Membrane expansion theory

8

Describe the membrane expansion theory

local anaesthetic diffuses into the membrane of the axon and prevents the sodium channels from opening

9

Describe the specific receptor theory

Local anaesthetic bind sodium channel and inactivates it

10

What is the key point of the specific receptor theory?

LA accesses the sodium channel from inside

11

Why must LA be lipophilic?

to be able to pass through the axon membrane

12

Why must LA be hydrophilic?

to be able to bind to the sodium channel

13

What 2 states does LA exist in?

Charged and uncharged

14

What does the proportion of charged and uncharged depend on?

the pKa of the drug and the pH of the environment

15

What does it mean if an LA has a low pKa?

more uncharged drug and so can pass through the axon membrane more rapidly

16

Name 4 properties of LA

Protein binding
Disassociation and solubility
Lipid solubility
Vasodilation

17

What type of nerve fibres are the easiest to block?

C fibres

18

What type of nerve fibres are the hardest to block?

A-alpha fibres