Topical Anesthetics

Question 1

What percentage is topical lidocaine base? What is it primarily used on?

Answer 1

5% used primarily on abraded or ulcerated tissue

Poorly water soluble. Amide.Pregnancy category B

Question 2

What forms is topical lidocaine base available in? What is the MRD?

Answer 2

Spray, ointment, patch, solution

200mg MRD.

Question 3

What is the difference between lidocaine base and HCl?

Answer 3

Lidocaine HCl is more soluble, leading to higher risk of toxicity

Question 4

What is 20% benzocaine gel primarily used for?

Answer 4

At injection sites and for periodontal probing

ester. Pregnancy category C

Question 5

What is used to mitigate patients gag reflex during radiographs and impressions?

Answer 5

Hurricaine spray 20%

Also available in gel, patch and liquid

Ester. Pregnancy category C. Poorly absorbed into systemic circulation

Question 6

What is Cetacaine spray/liquid composed of?

Answer 6

14% benzocaine- starts fast, short acting
2% tetracaine- starts slow, lasts long
2% butamben- intermediate/intermediate

Ester. Pregnancy category C. This is what we use in clinic for gag reflex

Question 7

What is dyclonine hydrochloride similar to in topical form?

Answer 7

Cocaine

Question 8

Characteristics of Dyclonine hydrochloride 0.5% solution?

Answer 8

Slow onset but long duration
No cross-sensitivity with other anesthetics
Is a ketone
Lozenge form
No longer on the market

Question 9

What is the commercial name for Lidocaine and prilocaine Eutectic mixture?

Answer 9

Oraqix

2.5% lidocaine + 2.5% prilocaine for a 5% mixture

Lasts about 20 min

MRD= 5 carts

Question 10

What is a eutectic mixture?

Answer 10

a mixture of two (or more) components that melts or solidifies at a single temperature that is lower than the melting point of either individual component. Ora qix is a liquid at room temperature that solidifies at body temperature.