Module 8 Flashcards
what is the mechanism of action of topical anesthetics
blocks nerve conduction at mucous membrane surface
decreases Na permeability –> decreased depolarization –> blocks nerve impulses
what are the steps for pre-injection topical application
- gel on cotton tip applicator
- site dried w/ gauze
- topical placed at site for 1-2 minutes
what is the anesthesia tissue depth of pre-injection topical application
2-3 mm
what are the 3 common topical anesthetics used in dentistry
- benzocaine
- lidocaine
- combo –> benzo + butamben + tetracaine
what is the generic name for benzocaine
hurricaine
is benzocaine an ester or an amide
ester
what is the onset of topical benzocaine
30 sec - 2 min
what is the duration of topical benzocaine
5 - 15 minutes
what is associated with benzocaine sprays
methemoglobinemia
is lidocaine an ester or an amide
amide
what is the onset of topical lidocaine
2 - 10 minutes
what is the duration of topical lidocaine
15 - 45 minutes
what is the MRD for topical lidocaine
300, but 200 safely
what category is lidocaine in regards to pregnancy and is there any impact on lactation
- category B
- small amounts can enter breast milk
what is cetacaine
benzocaine + butamben + tetracaine
is cetacaine an ester or amide
ester
what is the onset of topical cetacaine
30 sec
what is the duration of topical cetacaine
30 - 60 minutes
what is the MRD of cetacaine
200 mg
what category is cetacaine in regards to pregnancy and is there any impact on lactation
- category C
- use with caution
what category is benzocaine in regards to pregnancy and is there any impact on lactation
- category C
- unknown safety with lactation
T/F concentrations of topical anesthetics are higher than injectable local anesthetics
true - needed for diffusion through mucous membranes
T/F there are vasoconstrictors in topical anesthetics
false - NO vasoconstrictors –> increases absorption rate & risk of toxicity
what are the toxicities and adverse reactions of topical anesthetics
- irritation at site
- sloughing
- taste alteration
- CNS effects (excitation then depression)
- CV effects (decreased HR & BP, cardiac arrest)
how do you avoid toxic reactions from topical anesthetics
- know the relative toxicity of the drug being used
- know the concentration of the drug being used
- use the smallest volume
- use lowest concentration
- use least toxic drug for clinical scenario
- limit are of application
- avoid sprays
