Download Topical Anesthetics

Topical Anesthetics
Topical Anesthetic Application
• Topical anesthetic is applied to the
mucous membrane to anesthetize
terminal nerve endings (2-3mm) thus
increasing patient comfort during needle
penetration.
Concentration of Topical Anesthetic
• Concentration of topical anesthetic is
higher than the same agent that will
be injected
• Higher concentration facilitates
diffusion of the drug through the
mucous membrane or abraded skin
Vascular Absorption
• Topical anesthetics do not contain
vasoconstrictors and anesthetics (injectable)
are vasodilators, so absorption is rapid
• Levels of topical anesthetic may reach
similar levels of the injectable anesthesia
Benzocaine
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Ester (plasma)
Availability (Cetacaine, Hurricaine)
Not suitable for injection
Available as a liquid, gel, ointment, and
spray
• Onset is approximately 30 seconds
after application, recommend applying
for 1-2 minutes
• Duration of 5-15 minutes
Topical Anesthetics
Oral gels:
• Topicale
• Anbesol
• Baby Orabase
• Topex
• Orajel
• Etc.
Is Benzocaine an ester or amide?
Dyclonine Hydrochloride
Dyclone
• Ketone
• .5% solution, 200 mg
• Used as a rinse, or applied with a cotton tip
applicator
• Onset is up to 10 minutes
• Duration-may be up to one hour
• Systemic toxicity–rare
Dyclonine Hydrochloride
Cetacaine
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Benzocaine
Ester
Liquid
Rapid anesthesia- within
30 seconds
• Duration is 30-60 minutes
Lidocaine
• Topical or water soluble
preparation
• Amide
• Lidocaine ointment, 200 mg dose
• Exceptionally low incidence of
allergic reactions
• Xylocaine, Octocaine
EMLA (Eutectic Mixture of
Local Anesthetics)
2.5% Lidocaine
2.5% Prilocaine
Allergic Response to Topical
Anesthesia
• Esters (benzocaine and tetracaine)
• Allergic response is usually local
Topical Anesthesia Quiz
1. Your patient has atypical pseudo-cholinesterase
and your giving an injection. What topical
anesthetic should you use on this patient?
a. Cetacaine
b. Dyclone
c. Lidocaine
d. Benzocaine
e. b or c
2. Benzocaine is an:
a. Ester
b. Amide
3. Topical anesthetics contain vasoconstrictors.
a. True
b. False
4. Which topical anesthetic has a low incidence of
patient allergic reactions?
a. Benzocaine
b. Lidocaine
c. Cetacaine