question

Ideal local anesthetic properties

answer

•Potent local anesthesia •Reversible local anesthesia •Absence of local reactions •Absence of systemic reactions •Absence of allergic reactions •Rapid onset •Satisfactory duration •Adequate tissue penetration •Low cost •Long shelf Life •Sterilization by autoclave •Ease of metabolism and excretion

question

Local anesthetics are drugs that produce

answer

loss of sensation in localized area of body

question

Primary use of LA

answer

prevention and alleviation of pain

question

Chemical structure of LA

answer

◦Esters ◦Amides ◦Other

question

Site of action of LA

answer

nerve membrane that is responsible for conducting nerve action potential

question

Mechanism of action of LA

answer

◦Interfere with functions of neurons by reduce transient increase in sodium flow into nerve membrane ◦rate of depolarization decreased, increases the threshold for excitability, and prevents the propagation of action potential ◦May reduce permeability by competing with calcium by preventing onset of nerve conduction

question

Ester

answer

◦Cocaine ◦Ethylaminobenzoate (Benzocaine) has great quality ◦Tetracaine (Pontocaine) ◦Procaine (Novocaine) ◦Propoxycaine (in Ravocaine)

question

Amides

answer

◦Lidocaine (Xylocaine) ◦Mepivacaine (Carbocaine) ◦Bupivacaine (Marcaine) ◦Prilocaine ( Citanest) ◦Articaine (Septocaine)

question

Use commonly in dental office

answer

Amide

question

How LA absorption?

answer

Systemic absorption greater, especially with inflammation •Topical application on denuded mucous membranes - absorption can approximate IV injection

question

Purpose of vasoconstrictor

answer

•Reduces blood supply •Limits systemic absorption •Reduces systemic toxicity

question

Factors affect vascularity:

answer

degree of inflammation, vasodilation, warmth and massage

question

Why to Decreased systemic absorption

answer

reduces chance of systemic toxicity

question

To reduce absorption

answer

vasoconstrictor added

question

Where LA distribution

answer

◦throughout body ◦Highest concentrations in highly vascular organs

question

Metabolism of LA

answer

◦esters by plasma pseudocholinesterases ◦amides primarily by liver

question

Use amides carefully patients with

answer

Liver failure

question

LA excretion

answer

◦esters and amides excreted by kidney ◦use carefully in patients with kidney failure

question

Primary clinical effect of local anesthetics is to

answer

reversibly block peripheral nerve conduction

question

Order

answer

◦autonomic, cold, warmth, pain, touch, pressure, vibration, proprioception, and motor response ◦order may variety in patients ◦returns in reverse order

question

Adverse reaction

answer

•Adverse reactions and toxicity of local anesthetics directly related to plasma level of drug •Considering widespread use, potential for danger must be minimal •Deaths from local anesthetics difficult to document, but dental related mortality even rarer •Low incidence of ADR's (esters >amides)

question

Adverse reactions and toxicity of local anesthetics directly related to

answer

Plasma level of drug

question

Toxicity drug factor

answer

•Drug •Concentration •Route of administration •Rate of injection •Vascularity •Patient's weight •Rate of metabolism and excretion

question

Who are debilitating patients more likely to experience ADR?

answer

-Children and elderly -2 main systems affect by ADR - local - (Malignant hyperthermia not related to amides)

question

Two main system affect by ADR

answer

•CNS stimulation may precede CNS depression •restlessness, tremors, seizures, then CNS depression ◦CV •myocardial depression, cardiac arrest with peripheral vasodilation

question

What about local give ADV

answer

◦injection technique - most common is injection of excessive volume too quickly

question

Maglinant hyperthermia

answer

◦Inherited disease resulting in acute rise in calcium with symptoms of muscular rigidity, metabolic acidosis and extremely high fever ◦Mortality 50% ◦Most commonly associated with halothane, the inhalation anesthetic, and succinylcholine, the neuromuscular blocking agent ◦Treatment - supportive measures and administration of dantrolene ◦Patients with family history can receive amide LA's

question

Elective dental treatment should be rendered before pregnancy

answer

True

question

If needed, which may be administered to pregnant women

answer

Lidocaine

question

Which has been reported with larger doses are administered to mother near term

answer

Fetal bradycardia

question

FDA pregnancy category B

answer

Lidocaine and prilocaine

question

pregnancy category C

answer

Mepivacaine, articaine, and bupivacaine

question

Usual doses given to nursing mothers DO NOT affect health of normal nursing infant

answer

True

question

Allergy to LA

answer

•Range from rash to anaphylactic shock •Elicit allergy history before local chosen •Esters greater allergic potential •Locals with vasoconstrictors also have sulfites

question

No allergy to amide

answer

True

question

Antioxidant

answer

◦Sodium metabisulfite, sodium bisulfite, or acetone sodium sulfite ◦Prolong shelf life ◦Can precipitate symptoms of wheezing or chest tightness in asthmatic patients

question

Composition of LA solution

answer

•Vasoconstrictor •Antioxidant Sodium Chloride (Makes injectable solution isotonic) Sodium hydroxide(Adjusts ph) •Methylparaben and propylparaben

question

Methylparaben and propylparaben

answer

◦Preservatives ◦Not used in single dose cartridges

question

Amide

answer

•Amides are only class of anesthetics used parenterally. -lower hypersensitivity reaction rate, longer shelf life, more efficacious, and action suitable for most dental procedures. -No cross allergenicity between the amide lidocaine, other available amides, or esters has been documented.

question

Good for almost all dentistry

answer

Lidocaine ◦No cross allergenicity between other amides or esters ◦Some patients experience sedation ◦In toxicity reactions, likely to see CNS depression rather than CNS stimulation

question

◦In dentistry, lidocaine 2% with a:100,000 epi used for

answer

infiltration and block anesthesia

question

Lidocaine ADR

answer

hypotension, positional headache, shivering

question

Used for topical anesthesia as

answer

5% ointment, 10% spray, 2% viscous solution Topical onset rapid (2-3 minutes

question

Lidocaine with Epi 1:100,000 provides

answer

1-1.5 hrs duration of pulpal anesthesia with soft tissue anesthesia maintained for 3-4 hours)

question

Bupivacaine-prolonged duration

answer

◦Amide similar to lidocaine and mepivacaine ◦More potent and less toxic than other amides ◦Major advantage is greatly prolonged duration of action ◦Ideal for lengthy dental procedures when pulpal anesthesia of greater than 1.5 hrs expected or when postop pain anticipated (endo, perio, or oral surgery) ◦Similar to mepivacaine, but slower onset and longer duration ◦Should not be used in patients prone to self mutilation (mental patients or children younger than 12 years) ◦Pregnancy rating C-use only if others not an option

question

To avoid vasoconstrictor

answer

Mepivacaine plain

question

Usual dose form of Mepivacaine

answer

2% with 1:20,000 levonordefrin as vasoconstrictor

question

Use for short procedures when a vasoconstrictor is contraindicated (not often)

answer

Mepivacaine

question

What caution when using Mepivacaine

answer

should be exercised when using increased concentrations of la's without vasoconstrictor because systemic toxicity more likely

question

Except in unusual cases, benefit of shorter duration does not warrant

answer

eliminating vasoconstrictor, especially when concentration is increased

question

How long for procedure of Mepivacain without vasoconstrictor

answer

<30 minutes only (short procedu

question

Mepivacaine

answer

Rate of onset, duration, potency, toxicity similar to lidocaine with vasoconstrictor, procedure 30-90 minutes

question

Prilocaine

answer

◦Related chemically and pharmacologically to lidocaine and mepivacaine ◦Less potent and less toxic than lidocaine and has slightly longer action ◦Niche is situations when desired duration is somewhat longer than mepivacaine (without and with vasoconstrictor)

question

Related chemically and pharmacologically to lidocaine and mepivacaine

answer

Prilocaine

question

Less potent Less toxic than lidocaine Has slightly longer action

answer

Prilocaine

question

Which LA is similar to lidocaine and Mepivacaine

answer

Bupivacaine

question

Which LA is MORE potent LESS toxic than other amides?

answer

Bupivacaine

question

Major advantage of Bupivacaine

answer

greatly prolonged duration of action

question

Bupivacaine should not used in which patient

answer

Patients prone to self mutilation (mental patients or children younger than 12 years) ◦Pregnancy rating C-use only if others not an option

question

When using Bupivacaine, fatalities in obstetrics occurs during

answer

its early use in anesthesiology when much higher doses than those used in dentistry were used

question

-Newest amide approved in US by FDA in 2000 -Has become the most widely used LA

answer

Articaine

question

Articaine

answer

-Different derivation allows for greater lipid solubility and ability to cross lipid barriers such as nerve membranes -Enhanced action compared with other LA

question

Time life if Articaine

answer

T ½ 20 minutes compared to 90 minutes with lidocaine, so may be safer for reinjection during a dental visit

question

Average patient can tolerate Articaine

answer

2X as much lidocaine as articaine before max dose reached

question

Very high dose of Articaine can cause

answer

methemoglobin, but no cases reported in dental patients

question

Rarely causes paresthesia following mandibular block when 4% used

answer

True

question

Which LA More desirable in patients who may need reinjection, lowering risk for toxicity

answer

Articaine

question

Although clinical trials have not shown that articaine is better than other LA, many trials show that articaine slightly outperformed other LA that it was compared to

answer

TRUE

question

most commonly used (adrenergic agonists or sympathomimetics)

answer

Epinephrine and levonordefrin

question

What happend when LA dose not contain vasoconstrictor

answer

anesthetic drug more quickly removed from injection site and distributed into systemic circulation than if contained vasoconstrictor

question

How is duration for plain anesthetic (without vasoconstrictor)

answer

exhibit shorter duration of action and result in more rapid buildup of systemic blood level

question

any anesthetic given without vasoconstrictor more likely to be

answer

toxic than those given with vasoconstrictor

question

Must be weighed against possible systemic effect of vasoconstrictor

answer

True

question

Reasons for Use of Vasoconstricting Agents in Local Anesthetics

answer

-Prolong duration action -Increase depth of anesthesia -Delay systemic absorption of LA -Reduce toxic effect in systemic circulation -Reduce bleeding in area of injection and improve visibility of surgical site

question

In past, felt vasoconstrictors should not be used in patients with

answer

cardiovascular disease

question

Stemmed from fear that vasoconstrictor would

answer

elevate blood pressure too much

question

patient produces endogenous epi far in excess of that administered in dentistry in

answer

presence of inadequate anesthesia which sometimes occurs when vasoconstrictors are avoided

question

If controlled hypertension or angina can receive LA with

answer

epi

question

Administer in lowest possible dose using techniques that minimize

answer

systemic absorption

question

Do not use vasoconstrictor if

answer

uncontrolled hypertension, hyperthyroidism, unstable angina, MI or stroke in past 6 months should make appointment after controlled

question

For MI or CVA, when can use vasoconstrictor

answer

after 6 months

question

Patients with cardiovascular disease who are able to withstand dental treatment should/should not receive administration of epinephrine-containing la's

answer

should

question

Maximum safe dose of epinephrine in healthy patient

answer

0.2 mg

question

Maximum safe dose of epinephrine in appropriate cardiac patient is

answer

0.04 mg

question

Dental Practitioner should become familiar with

answer

at least 2 agents, or short, an intermediate, and a long acting agent

question

Short Duration (Pulpal = 30 minutes)

answer

-Lidocaine plain (without) -Mepivacaine plain (without) -Prilocaine plain (infiltration)

question

Intermediate Duration (Pulpal 30-60 minutes)

answer

-Mepivacaine with vasoconstritor -Prilocaine plain (block) (without) -Prilocaine with (60-90 minutes) -Articaine with (60-90 minutes)

question

Long Duration (Pulpal > 90 minutes)

answer

Bupivacaine with

question

Duration of lidocaine with vasodilation in pupal

answer

60 min

question

Duration of lidocaine with vasodilation in soft tissue

answer

3-5 hrs

question

Mepivacaine without (plain) in pupal

answer

40 min

question

Mepivacaine without (plain) with infilatration in pupal

answer

20 min

question

Mepivacaine without (plain) in soft tissue

answer

2-3 hrs

question

Mepivacaine with in pupal Mepivacaine with in soft tissue

answer

60-90 min 3-5 hrs

question

Prilocaine without (plain) in soft tissue Prilocaine with infiltration in soft tissue

answer

2-4 hrs 1.5-2 hrs

question

Prilocaine without (plain) in pupal Prilocaine without (plain) in pupal with infiltration

answer

60 mintues 10 min

question

Prilocaine with in pupal Prilocaine with infiltration in pupal

answer

60-90 min 45-60 min

question

Prilocaine with in soft tissue Prilocaine with 1:200,000 epinephrine

answer

3-8 hrs 2-4 hrs

question

Bupivacaine with in pupal Bupivacaine with in soft tissue

answer

90-180 min 4-9 (12)

question

Articaine with in pupal Articaine with in soft tissue

answer

60-90 min 3-4 hrs

question

Dental Concerns LA

answer

-Detailed medication/health history -Use maximum safe dose of LA and vasoconstrictor based on physical health and medication history -Record local anesthetic concentration, vasoconstrictor concentration, and number cartridges used -Check BP -Consultation with MD may be advised

question

Instructions for Patients Receiving LA

answer

-Advise patients to tell dental practitioner if feeling anxious, nervous, or if having heart palpitations -Most of these symptoms can be avoided by lowering dose or switching to another la -Some LA can cause sedation (lidocaine) -Use caution if opioid analgesic or antianxiety drug also prescribed -Avoid driving or doing anything that requires concentration -Avoid eating or drinking very hot or cold foods or drinks

question

Which can more likely to be absorbed and cause systemic toxicity

answer

Hydrochloride salt

question

When topical Lidocaine - base preferred

answer

large areas of mucosal surfaces are ulcerated, abraded, denuded, or erythematous

question

What form of topical anesthesic base available

answer

jelly, oral topical solution Hydrochloride available as ointment, oral topical, oral aerosol

question

poorly absorbed and lacks significant systemic toxicity, but can cause hypersensitivity reactions

answer

topical bezocaine

question

Dental Hygiene ConsiderationsTopical Anesthetic Agents

answer

-Limit area of application -Select topical based on patients medication/health history -Avoid using spray formulations

question

Dental Concerns for topical anesthesia

answer

-Inform patients of ADR potential -Educate patient to relate any ADR -Sedation with lidocaine and need to be accompanied -Refrain from eating and drinking heat or cold

question

Topical anesthetic include

answer

Benzocaine Lidocaine

question

Used of topical anesthetic

answer

-Applied to mucous membranes -Limit area of application -Use smallest volume of least toxic topical -All can be absorbed systemically

Pharmacology- Local anesthesia – Flashcards

Unlock all answers in this set

Haven't found what you were looking for?

Search for samples, answers to your questions and flashcards