Chapter 08 - Topical Anesthestics Flashcards
- Eutectic mixtures have which of the following characteristics?
a. The work more rapidly than most other topicals.
b. They penetrate deeper into skin than mucosa.
c. Their melting points exceed that of their ingredients acting alone.
d. Their formulations facilitate deeper and more efficient penetration of tissue compared with their ingredients acting alone.
d. EUTECTIC = a substance that has a lower melting point than any of its ingredients (greek, eu - tektos/tekein = melt/thaw easily)
- lower melting points facilitate penetration through tissue barriers
- formulated primarily in base form so that they can provide anesthesia more rapidly
- Which of the following lists is most accurate when describing topical anesthetic uses?
a. Before exposing radiographs, before injections, before placing retraction cord.
b. Before dental hygiene thx and in subgingival tissues.
c. In procedures confined to mucosa and before taking impressions.
d. All of the above
d. all of the above
- Which ONE of the following statements is INCORRECT regarding maximum recommended doses of topical anesthetics?
a. The are sometimes difficult to track.
b. MRDs are not always provided.
c. Spray forms have easy-to-track dosing.
d. Oraquix has easy-to-track dosing.
c. Metered sprays ae generally easier to track. Unmetered sprays are not.
- Generous quantities of topical and injected anesthesia have been administered, when the patient begins to shake and appears agitated and anxious. Is there a reason for concern?
a. Yes, because these may be early signs of CNS depression.
b. No, because this is a very nervous patient and he/she hates dental appointments.
c. No, because the doses of injectable anesthetic were within safe guidelines.
d. Yes, because the patient is a dental phobic.
a. Tremors and agitation may be early signs of CNS depression.
They are also reactions that occur in response to stress of dental appointments.
It is important to remain alert to the development of further signs and symptoms of CNS depression.
- Topical anesthetic mixtures may be of benefit in all but which ONE of the following ways?
a. Combinations may increase therapeutic ranges.
b. Combinations may increase penetration depths.
c. Mixtures may allow drugs to be used as topicals that are not suitable when used alone.
d. Mixtures decrease the potential for adverse reaction.
d. Adding additional drugs does not decrease the potential for adverse reactions; it generally increases the potential.
- All of the following statements are true regarding compounded drugs, EXCEPT:
a. Compounded drugs are formulated for individuals for whom they are prescribed.
b. Compounded drugs maybe used on other individuals as long as the use is the same as the original use.
c. Compounded drugs may contain much larger quantities of drug compared with multiuse commercial preparations.
d, Compounded topicals are dispensed by prescription
b. Compounded drugs, incl. compounded topicals, may only be used on individuals for whom they may have been prescribed.
- The predominantly base form of lidocaine topical anesthetic is safer than the predominantly hydrochloride salt.
A. True, the base form has less ability to be absorbed systemically.
- Dyclonine hydrochloride is an excellent and very durable topical anesthetic and belongs to which ONE of the following classes of anesthetic?
a. Amide
b. Ketone
c. Ester
D. None of the above
b. Dyclonine has a ketone linkage as opposed to amide or ester.
Q8-1: List uses of topical anesthetic drugs.
A8-1:
1. penetration site anesthesia prior to needle insertion
2. discomfort related to radiographic film placement,
3. periodontal evaluation and treatment,
4. procedures confined to superficial mucosa,
5. the placement of retraction cord and rubber dams (when anesthesia has not been established prior to placement)
6. controlling gag reflexes.
Q8-2: Explain why it is difficult to determine the dose of topical anesthetics used.
A8-2:
- MDRs for many topical products do not exist
- difficulty determining how much was dispensed or absorbed (before being washed away in saliva)
- patches and metered sprays offer more precise calculations as do some single-dose application systems.
- Liquids and gels in multi-use containers and non-metered sprays present problems
Q8-3: What are compounding rules?
A8-3:
- developed by the FDA’s Modernization Act of 1997
- “The compounded product must be individually prescribed for an identified patient.”
Q8-4: How are topical anesthetics commonly dispensed and applied?
A8-4: They may be dispensed as liquids, gels, creams, ointments, metered and un-metered sprays, and subgingival dual-phase systems.
Application methods include the use of cotton swabs, sprays, air injection systems, and subgingival delivery systems with blunt-tipped devices.
Q8-5: Discuss the use of metered spray topical anesthetics.
A8-5:
- significant benefit over unmetered sprays when considering toxicity
- some unmetered sprays call for depressing the nozzle only one-half second per application. This rather limited spray interval is difficult to accomplish clinically, and applications may routinely exceed the half-second interval.
Q8-6: Discuss the advantages of using a liquid to gel topical anesthetic.
A8-6:
- easily applied because of its liquid state at room temperature and its rapid transformation to a gel-like state once placed sub-gingivally.
- provides excellent tissue anesthesia and occasional pulpal anesthesia
- has wide margins of safety, a known MRD, and easily quantified volumes dispensed because packaged in cartridge form
Q8-7: Give examples of common topical anesthetic agents.
A8-7: Common topical anesthetic agents are: 1. benzocaine,
dyclonine hydrochloride,
lidocaine,
prilocaine,
tetracaine hydrochloride (only in mixtures)
butamben (only in mixtures)
