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Flashcards in Local anasthetic agents Deck (10)
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1
Q

Which form of LA enters the cell

A

LA, uncharged

2
Q

MOA of LA

A

Reversibly blocks open Na+ channels from within the cell. Must enter the cell (LA) and become ionized (LA+) to bind.

3
Q

Order of nerve block for LAs

A

Pain fibers first
sensation fibers next
motor function blocked last

4
Q

What is potency correlated with for LAs

A

lipid solubility, more lipid soluble = more potent

Size, smaller size = more potent

5
Q

Effect of vasoconstriction in LA

A

reduce systemic absorpion. If drug does not have vasoconstriction properties, may add epinephrine

6
Q

metabolism of LAs

A

Amide LAs metabolized in the liver by CYP P450

Ester LAs metabolized in plasmas by plasma cholinesterase

7
Q

Factors affecting clearance of LAs (4)

A

Patient age
Liver function
Cardiovascular function
Type of LA, esters degraded faster

8
Q

Systemic toxicity of LAs

A

Hypersensitivity of metabolites of Ester LAs

Hypersensitivity to methylparaben preservative

9
Q

CNS toxicity of LAs

A
sedation
lightheadedness
visual and auditory disturbances
tounge numbness and metalic taste
muscular twitching, nystagmus, and convulsions
10
Q

Cardiovascular toxicity of LAs

A

Most feared toxicity, affect conduction (bupivicaine)

IV infusion of lipid can treat cardiotoxicity