question

Topical

answer

implies that the anesthetic will be applied to a body surface such as the skin or mucous membrane

question

Uses of topical anesthetic

answer

-before local anesthetic injection -tx of minor injuries to the gingiva and oral mucosa -increase comfort during minor dental and hygiene procedures -reduce a patient's gag reflex while taking radiographs or impressions

question

True OR False: Topical anesthetics can replace local anesthesia

answer

False; Topical anesthetics should not replace local anesthesia because they do not provide pulpal anesthesia and will not be effective if root sensitivity is a concern

question

True OR False: Topical anesthetics are available OTC

answer

True; people of all ages can use them to ease pain from canker sores, braces, teething, apthous ulcers, dentures, toothaches, etc.

question

Ideal characteristics of a topical anesthetic

answer

- nonallergenic -produce no damage to the tissue -pain-free application -have an acceptable taste -remain at site of application -produce reliable, effective anesthesia with sufficient duration -does not induce systemic toxicity

question

What is the mechanism of action of topical anesthetics?

answer

Similar to their injectable counterparts: block nerve conduction at the surface, the permeability of sodium ions is decreased resulting in decreased polarization and an increased excitability threshold thus loss of sensation

question

Topical anesthetics, however, do not contain a _________ and have a _______ concentration in order to diffuse through the mucous membrane.

answer

vasoconstrictor;higher

question

Topical agents are available as.....

answer

-gels -creams -ointments -sprays (metered and unmetered) -liquids -lozenges

question

Depending on the form, concentrations can range from ___% to ___%

answer

0.2%-20%

question

Topical should remain at site for _____ minutes to ensure effectiveness

answer

1-2 minutes

question

What is the depth of topical anesthesia?

answer

2-3mm

question

Which anesthetic has the FDA released advisory statement regarding methemoglobinemia?

answer

Benzocaine; Methemoglobin builds up in the blood, hindering the effective transport of oxygen to body tissues *should not be used under two years old

question

Signs and symptoms of methemoglobinemia

answer

pale, gray, or blue colored skin, lips and/or nail beds, fatigue, shortness of breath, heartache, lightheadedness *occur within minutes to hours after topical benzocaine admin.

question

What signs and symptoms of methemoglobinemia occur at the site of injection?

answer

-irritation -stinging or burning - sloughing -tissue discoloration -temporary alteration of taste

question

Where are the most prominent effects of topical anesthetics?

answer

The CNS; excitatory effects are the initial signs and symptoms of an overdose (brief or not at all). Other signs include: -dizziness -tinnitus -visual disturbances -disorientation -unusual nervousness or apprehension -localized involuntary muscular activity

question

CNS depression

answer

results in slurred speech, drowsiness, and respiratory impairment

question

Toxic overdose

answer

results in seizures, unconsciousness, and respiratory impairment

question

Which group(s) of people are we concerned with methemoglobinemia?

answer

-children under the age of 2 -adults with breathing problems (asthma, emphysema, COPD) -those with heart disease -smokers

question

What new product has been developed that delivers dental anesthetic by way of nasal spray

answer

Kovacaine mist; 3% tetracaine HCL with 0.05% oxymetazoline HCL

question

Transdermal

answer

patch placed directly on the skin *Synera, Lidoderm

question

Transoral patch

answer

The first FDA approved patch for intraoral placement *Dentipatch

question

Benzocaine

answer

an ester; one of the more common and widely used and it exists almost entirely in its base form, making absorption slow therefore it has a low potential for systemic toxicity

question

Available concentrations of Benzocaine

answer

ranges from 6-20% -gel, cream, ointment, lozenge, liquid, spray, and patch

question

Mostly commonly used concentrations of benzocaine

answer

20%

question

Benzocaine onset of action

answer

rapid, onset can occur as early as 30 seconds and have its peak affect at 2 minutes

question

Benzocaine duration

answer

5 to 15 minutes

question

Maximum recommended dose of benzocaine

answer

There is no published MRD

question

Metabolism/excretion of benzocaine

answer

metabolized via hydrolyzed in plasma and to a lesser extent in the liver by cholinesterase. Excretion occurs primarily through kidneys with only a small portion remaining unchanged in urine

question

Benzocaine & pregnancy and lactation

answer

FDA category C/excretion in breastmilk is unknown, use with caution

question

Special Considerations for benzocaine

answer

Methemoglobinemia has been reported following topical anesthesia use, particularly with higher concentrations of 14-20% spray applications applied to the mouth and mucous membrane. Should not be used children younger than 2 years old.

question

Lidocaine

answer

good alternative is patient has a sensitivity to esters, most commonly as an ointment

question

What two forms is lidocaine available in?

answer

As a base or a hydrochloride salt

question

Base form of lidocaine

answer

poorly water soluble and has poor penetration as well as absorption abilities; preferred for application to mucous membranes and covering large areas

question

Hydrochloride salt from of lidocaine

answer

Water soluble and easily penetrates and is absorbed by the tissues, significantly increasing the risk of toxicity

question

Available concentrations of Lidocaine

answer

most common in 2% or 5% -ointment, spray, patch, solution

question

Lidocaine onset of action

answer

between 2 and 10 minutes

question

Lidocaine duration

answer

depends on the method of applications approx. 15 to 45 minutes

question

Maximum recommended dose of lidocaine

answer

200mg (300mg manufacturer recommendation)

question

Metabolism/excretion of lidocaine

answer

metabolized in the liver and excreted by the kidneys with less than 10% remaining unchanged

question

Lidocaine & pregnancy and lactation

answer

FDA category B/enters breastmilk in small amounts, use with caution

question

Special Considerations for Lidocaine

answer

Always follow a manufacture's application directions and ask questions of physician staff if necessary

question

Which local anesthetic has a unique classification that is neither an amide or an ester, but a ketone?

answer

Dyclonine hydrochloride

question

Who is Dyclonine hydrochloride good for?

answer

Patients with sensitivities to traditional topical anesthetics *available OTC as Sucrets lozenges

question

Available concentrations of Dyclonine hydrochloride

answer

formulated for use in dentistry as 0.5% or 1% solution -lozenges

question

Dyclonine hydrochloride onset of action

answer

slow; may take up to 10 minutes to become effective

question

Dyclonine hydrochloride duration

answer

average duration is 30 minutes; however effects may last up to an hour

question

Maximum recommended dose of Dyclonine hydrochloride

answer

200mg (40mL of 0.5% solution or 20mL of 1% solution)

question

Metabolism/excretion of Dyclonine hydrochloride

answer

No information is available

question

Dyclonine hydrochloride & pregnancy and lactation

answer

FDA category C/caution is recommended during lactation

question

Tetracycline hydrochloride

answer

ester; considered the most potent topical and is typically combined with other drugs

question

Available concentrations of Tetracycline hydrochloride

answer

2%

question

Tetracycline hydrochloride onset of action

answer

slow; peak effects may take up to 20 minutes

question

Tetracycline hydrochloride duration

answer

approx. 45 minutes

question

Maximum recommended dose of Tetracycline hydrochloride

answer

20mg for topical administration; 1mL of a 2% solution

question

Metabolism/excretion of Tetracycline hydrochloride

answer

metabolized by plasma pseudocholinesterase/ excreted by the kidneys

question

Tetracycline hydrochloride & pregnancy and lactation

answer

FDA category C/ caution is recommended during lactation

question

Special Considerations for Tetracycline hydrochloride

answer

Highly soluble in lipids, making absorption into local tissues very rapid

question

Why are topical anesthetic agents mixed and used in combinations?

answer

To increase the anesthetic effect

question

What is Cetacaine a combination of?

answer

ester, triple action formula of benzocaine, butamben, and tetracaine Benzocaine- provides quick onset Tetracaine- allows deeper penetration, thus increased duration of action

question

Available concentrations of Cetacaine

answer

triple-active formula of benzocaine 14%, butamben 2%, and tetracaine hydrochloride 2% -prescription only spray, liquid, gel forms

question

Cetacaine onset of action

answer

rapid; approx. 30 seconds

question

Cetacaine duration

answer

typically 30-60 minutes

question

Maximum recommended dose of Cetacaine

answer

Spray administered for 1 second, gel & liquid 200mg

question

Metabolism/excretion of Cetacaine

answer

hydrolysis via cholinesterase

question

Cetacaine & pregnancy and lactation

answer

FDA pregnancy category C/ use caution while nursing

question

Special Considerations for Cetacaine

answer

Tetracaine is highly-lipid soluble, making absorption into local tissues very rapid. not suitable for injection

question

Eutectic mixture

answer

a mixture of two elements that together have a lower melting temperature than any of the individual components, this increases the concentration and enhances the drug's properties, resulting in a faster more penetrating longer-acting agents

question

EMLA (eutectic mixtures of local anesthetics)

answer

amide; the composition of 2.5% lidocaine and 2.5% prilocaine as an oil-in water emulsion

question

EMLA is available as a

answer

cream or disc, and may require an occlusal dressing

question

EMLA uses include

answer

venipuncture, circumcision, and minor gynecologic procedures; intact, non-mucosal skin

question

When used as directed systemic toxicity is _____

answer

low; however if utilized not as prescribed the systemic absorption of lidocaine and prilocaine may become a side effect

question

True OR False: The FDA released a public safety advisory expressing concerns and warning the public of potential danger associated with EMLA

answer

True

question

The first documented use of lidocaine/prilocaine used in the oral cavity was done in 1985 by _____ and ______.

answer

Holst and Evers

question

Available concentrations of EMLA

answer

2.5% lidocaine and 2.5% prilocaine *not available for intraoral use

question

EMLA onset of action

answer

Satisfactory results achieved in 1 hour, wit exceptions of genital mucosa which is 10-15 minutes. None reported for intraoral use

question

EMLA duration

answer

No information reported for intraoral use

question

Maximum recommended dose of EMLA

answer

No information reported for intraoral use

question

Metabolism/excretion of EMLA

answer

Primarily in the liver

question

EMLA & pregnancy and lactation

answer

As a eutectic mixture, FDA category B. Caution should be taken during lactation

question

Which anesthetic has the same composition as EMLA but can be used intraorally?

answer

Oraqix and is a gel

question

Oraqix is a

answer

amide; microemulsion in which the oil phase is a eutectic mixture in a ratio 1:1 weight

question

Oraqix remains as a _____ at room temperature in the cartridge, it begins to ______ into a gel upon application into the periodontal pocket an reaching body temperature.

answer

liquid, thicken

question

True OR False: Oraqix provides both pulpal and gingival anesthesia

answer

False; it only provides gingival comfort during prophylaxis, periodontal assessment, and NSPT

question

Available concentrations of Oraqix

answer

5% periodontal gel (2.5% lidocaine and 2.5% prilocaine)

question

Oraqix onset of action

answer

Occurs by 30 seconds, longer wait time does not enhance the anesthetic effect

question

Oraqix duration

answer

Approx. 30 minutes (average 14-31 minutes)

question

Maximum recommended dose of Oraqix

answer

Five cartridges at one treatment session

question

Metabolism/excretion of Oraqix

answer

Mainly metabolized in the liver

question

Oraqix & pregnancy and lactation

answer

FDA pregnancy category B/ caution should be taken if administered to nursing mother

question

Special Considerations for Oraqix

answer

Do not inject!

question

Which is the following topical anesthetics is classified as an amide? A. Benzocaine B. Lidocaine C. Tetracaine D. Dyclonine

answer

B. Lidocaine

question

Benzocaine is available in all of the following preparations EXCEPT one. Which one is is the exception? A. Cream B. Gel C. Spray D. Patch E. Injectable

answer

E. Injectable

question

All of the following statements are true except one, which one is the exception? A. Allergic reactions associated with topical is rare B. Topical anesthetic are made available OTC C. The more topical placed at the site of needle penetration, the better D. Tetracaine hydrochloride is considered the most potent topical anesthetic

answer

C. The more topical placed at the site of needle penetration, the better

question

Which of the following topical anesthetics has the FDA pregnancy category B? A. Tetracaine hydrochloride B. Benzocaine C. Lidocaine/prilocaine D. Dyclonine hydrochloride

answer

C. Lidocaine/prilocaine

question

Which of the following would be an indication for use of a topical anesthetic? A. To minimize patient's gag reflex B. To numb a patient's tongue so they will stop talking C. To achieve pulpal anesthesia D. To achieve anesthesia of the bone

answer

A. To minimize patient's gag reflex

question

All of the following are true regarding maximum recommended doses for topical anesthesia EXCEPT: A. It is difficult to monitor exact doses given B. Patches are a good way to monitor exact doses C. MRD dose not exist for all topical anesthetics D. Exact doses can be measured using a cotton tip applicator

answer

D. Exact doses can be measured using a cotton tip applicator

question

Concentrations available in OTC products can be as high as those administered professionally in the dental office. A. True B. False

answer

A. True

question

Which of the following topical anesthetics do not always require a prescription? A. EMLA B. Cetacaine C. Oraqix D. Benzocaine

answer

D. Benzocaine

question

All of the following are considered ideal properties of a topical anesthetic except which one? A. It should produce no damage to the tissue B. It should have an acceptable taste C. It should not induce systemic toxicity D. It should be allergenic

answer

D. It should be allergenic

question

Which method of delivery is recommended to to decrease the risk of methemoglobinemia? A. Unmetered spray B. Metered spray C. Unmetered spray with disposable nozzle D. Metered spray with disposable nozzle

answer

D. Metered spray with disposable nozzle *Metered spray with disposable nozzle. Both of these features help to minimize the risk systemic toxicity and/or overdose. The disposable nozzle allows the clinician to direct the spray specifically to the desired area, while the metered spray allows control over how much is applied.

question

Topical anesthetics generally penetrate _____ into the tissue. A. 1 to 2mm B. 2 to 3mm C. 3 to 4mm D. 4 to 5mm

answer

B. 2 to 3mm

question

Which of the following local anesthetics agents is found in Oraqix? A. Mepivacaine B. Prilocaine C. Procaine D. Benzocaine E. Articaine

answer

B. Prilocaine

question

The concentrations of topical anesthetics are greater than those of their injectable counterparts. Topical anesthetics do not contain vasoconstrictors. A. The first statement is true, the second is false B. The first statement is false, the second is true C. Both statements are true D. Both statements are false

answer

C. Both statements are true

question

All of the following describe advantages of single unit-dose applications of topical anesthetics EXCEPT which one: A. Prevents cross-contamination B. Doses administered can be monitored C. Less messy D. Requires less administration time

answer

D. Requires less administration time

question

EMLA is approved by the U.S Food and Drug Administration for use on which of the following: A. Intact skin B. Mucous membranes C. Hard palate D. Soft palate

answer

A. Intact skin *Even though studies do exist on the effectiveness of EMLA cream used intraorally, the cream is not approved by the FDA for intraoral use.

question

Pulpal anesthesia can be achieved using 2.5% lidocaine and 2.5% prilocaine gel mixture. A. True B. False

answer

B. False *This eutectic mixture, when at room temperature, is in the form of a gel developed to be placed down inside the periodontal pocket. It is capable of penetrating only into the periodontal pocket, blocking nerve conductions only in the gingival tissue, and cannot be used to achieve pulpal anesthesia.

question

Which of the following anesthetics is considered a ketone? A. Benzocaine B. Dyclonine hydrochloride C. Lidocaine D. A and B

answer

B. Dyclonine hydrochloride

question

If plasma concentrations become to high in the body, the most prominent systemic effect will occur in which of the following systems? A. Respiratory B. Cardiovascular C. Central nervous system D. B and C

answer

D. B and C *Excitatory effects of the central nervous system are often displayed at the initial sign of overdose. These signs and symptoms include dizziness, visual disturbances, tinnitus, disorientation, unusual nervousness or apprehension, and localized involuntary muscular activity. In the cardiovascular system, patients may experience bradycardia and hypotension, leading to rare cases of cardiac arrest.

question

Allergic reactions associated with topical anesthetics appear at the site. It is not necessary to review a patient's medical history before applying a topical anesthetic agent. A. The first statement is true, the second is false B. The first statement is false, the second is true C. Both statements are true D. Both statements are false

answer

A. The first statement is true, the second is false

question

All of the following are possible localized adverse reactions associated with topical anesthetics EXCEPT one. A. Burning or stinging B. Sloughing C. Tissue discoloration D. A and B E. Increased heart rate

answer

E. Increased heart rate

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