LA 1 Flashcards
What do you call LA in America?
Novocaine
What is analgesia?
Pain relief medication
What are the 3 structures compromising LA?
Why is the role of the aromatic ring in LA?
Lipid solubility potency
More soluble more potent
What is the role of the intermediate link in LA?
Determines biotransformation
We use amide now, less likely for patients to be allergic
Where are the amides linkagages metabolised?
In the liver
What does the LA block in the nerve?
Reversible blocks the sodium channel and blocking the depolarisation (action potential) and signals of pain
Blocking excitable membranes
Does LA act on all excitable membranes?
Yes
What creates a quicker onset time of LA?
The higher the tissue pH the quicker the onset time
LA goes in at neutral or charged form?
Neutral
When does LA become charged?
When it is propagated
What 2 organs are important in LA excretion?
Liver and kidneys
In what form does LA penetrate the lipid part of the neuron membrane?
Uncharged lipophilic form (fat soluble)
What is the concentration of LA in the UK?
2% preparation with 1:80,000 adrenaline
How do you calculate how much LA to give?
7mg/kg of body weight, up to 50pmg
What is the max LA you can give?
500 mg
Compare mepivacaine and lidocaine?
Melivicaine doesn’t need a vasoconstrictor LA does
What is a benefit of melivocaine?
Useful to ensure good blood supply
What vasodilator can accompany prilocaine?
Felylressin in UK
What is more toxic prilocaine or lidocaine?
Lidocaine remains in the plasma longer than prilocaine
When would you use bupivacaine?
Long duration of numbness, for surgery or post-op
What is the maximum recommended dose of articaine?
7mg/kg
(88mg is standard 2.2ml cart)
Are LAs vasodilators or vasoconstrictors?
Vasodilators?
Why is articaine good for patients with liver failure?
Ester group tagged on, so pseudocholonesterases are metabolised in the plasma, don’t rely on liver metabolism
What is the duration of numbness for pulpal anaesthesia for articaine and lidocaine?
60 mins
What has a shorter half life, lidocaine or articaine?
Articaine, top up more
