Dh102 w3 study

What anesthetic has the most vasodilatory properties?

Procaine

Which is an ester

What anesthetic has the least vasodilatory properties?

Mepivacaine and Prilocaine

Which are amides

Why is knowing local anesthetics are vasodilators?

Clinicians want the least amount of bleeding as possible at the site we are scaling.  If an anesthetic is used, we would prefer adding a vasoconstrictor in it so the blood vessels will constrict to allow less bleeding at the site we are scaling. However, vasoconstrictors have sodium bisulfite in it among other things.  Many people are allergic to sulfites, so we don’t use a vasoconstrictor with them, but still want the least amount of bleeding as possible.  The amides, Mepivacaine and Prilocaine plain are available without vasoconstrictors, and also have the least vasodilatory properties. One of those anesthetics is what we would need to choose.  

What does vasodilation of the blood vessels cause?

**Increased absorption into the bloodstream carrying the anesthetic away from the site**

\- **A decrease in the duration of the anesthetic due to some of it being carried away.** 

\- **Higher blood levels in the body leading to possible toxicity.**

\- **Increased blood flow to the site of Injection.**

What are vasoconstrictors?

**Combined with anesthetics to counteract vasodilating properties of LA’s.** 

\- **Provides a decrease in in the blood flow at site of scaling.**

\- **An increased duration  (6X’s more) of the anesthetic’s effect by localizing the high concentration of the drug in the area of injection, within the nerve improving the success rate and intensity of the nerve block.** 

\- **Slows** **absorption of the anesthetic into the cardiovascular system lowering toxicity.**

Vasoconstrictors in the U.S.

Epinephrine and Levonordefrin

What is Epinephrine

The most used, and considered the ‘benchmark’ upon which all other vasoconstrictors are compared.

Sympathomimetic drugs (AKA adrenergic drugs Are ?

Synthetic Epinephrine so mimics/ resembles our real epinephrine hormone that it is called sympathomimetic-Levonordefrin is also a synthetic catecholamine.

The catecholamines do what to our body?

increase heart rate, contract blood vessels, dilate air passage and participate in the “fight -or-flight: response of the sympathetic nervous system

The Use of Vasoconstrictors in Dentistry

Clinicians always weigh the benefit vs the risk of adding a vasoconstrictor to the medically compromised.  We also release epinephrine in our system when we have dental apprehension. Since the patient already has epinephrine being released due to fear we have to be careful giving additional epinephrine in the anesthetic.

What dose do we give if someone has heart condition, uncontrolled hyperthyroidism, angina, or high blood pressure?

we may choose to give a ‘cardiac dose’ (only 2 cartridges). At that amount there is no change in the body.

More diluted formulations of epi are safer for patients who are cardiovascularly compromised.

What type of epi is more safe for patient that are cardiovascularly compromised?

more diluted formulations of epi

Epinephrine is ?

adrenalin

How does epinephrine cause vasoconstriction?

By activating the adrenergic receptors located in most tissues, but once in the bloodstream, epi is rapidly inactivated by the adrenergic nerves.

These adrenergic receptors are divided into 2 divisions:

Alpha Receptors and Beta Receptors

What are alpha receptors

constriction of smooth muscle

What is Alpha 1 or a1

excitatory

What is Alpha 2 or a2

inhibitory

**Beta Receptors-** 

Most sensitive to epinephrine

 Beta 1 or b1 

Stimulating effects in the heart (1 heart)

Beta 2 or b2\*\*

inhibitory (relaxes & dilates bronchi) bronchial smooth  muscles      ( lungs)  

Epi Dilutions:  referred to as ratios

1:100,000 ratio   Means 1gram (or 1000 mg) of drug dissolved in a 100,000 ml or 0.01 mg/ml.  

1:50,000 (made with 2% Lidocaine) 

Only used in surgery for hemostasis

1:100,000 

made with 2% Lidocaine, 4% Articaine & 0.05% Bupivacaine

1:200,000 

made with 4% Prilocaine, 4% Articaine & 0.05% Bupivacaine

Sodium Bisulfite Preservative

Local anesthetics are made from acid salts which are slightly acidic causing the pH to go to a 6.5

The sodium bisulfite is also acidic and drops the pH even further down to a range of 3.0 to 5.5 which is Very acidic. 

The Maximum Recommended Dose of epinephrine (MRD) for a healthy patient per day is

0\.2mg. (10 – 11 cartridges)

Maximum Recommended Dose of epinephrine for a patient with a cardiac condition, or a patient taking a tricyclic antidepressant

2 cartidges

Levonordefrin is

It is only available with  2% Mepivacaine in a 1:20,000 dilution which is 5 X greater than epinephrine 1:100,000 but produces the same effects.

The rate of systemic absorption of local anesthetics depends on

The total dose, concentration, route of administration, vascularity of the tissues, and presence or absence of a vasoconstrictor.

 **Sodium Chloride**

A buffer which when added to a LA creates an injectable isotonic solution.

Methylparaben

**A bacteriostatic agent that** __**used to be**__ **added to a LA w/out a vasoconstrictor to prevent bacterial growth, but since 1984-** __**not anymore**__ **due to too many allergies.**  

What is the amide prilocaine proprietary Names

 Citanest or Citanest Forte

Mepivacaine

Carbocaine. Polocaine

Articaine

Septocaine

Lidocaine

Xylocaine

Bupivacaine

Marcaine

Vasoconstrictors are also called

Vasopressors

Duration of blood control

Bupivacaine

has the highest % of protein binding & is the most lipid soluble of all the local anesthetics; therefore it has the longest duration and the most potent.  However, it has the highest pKa and so has the slowest onset.

The higher the pKa of an anesthetic

the slower (or longer) the onset of action.

The lower the pKa of an anesthetic

the fastser (or shorter) the onset of action.

Mepivacaine and Prilocaine have the least

**vasodilatory effects**.

Both are quite effective if a vasoconstrictor is contraindicated

Short-Acting Duration LA

Provide pulpal anesthesia for approx.. 30 minutes & do not contain a vasoconstrictor.

Intermediate Acting Duration

Provide pulpal anesthesia for approx.. 60 minutes & contain a vasoconstrictor. 

Long-Acting: Duration

Provide pulpal anesthesia of 90 min and contain a vasoconstrictor

The benefits may outweigh the risk in some cases and maybe just a cardiac dose (2 cartridges) might be given.  Cardiac doses have no 

systemic effect, and is given for various medical conditions other than involving the heart.

Sulfites are among the top food allergies.

• 5 – 10% of asthmatics are allergic to sulfites How will it show?

As respiratory issues

If the patients are allergic to sodium bisulfite or metabisulfite (sulfate)

The above patients should not be given an LA with a vasoconstrictor but could be given an amide LA with no vasoconstrictor (Mepivacaine plain or Prilocaine plain).

The need for Hemostasis (bleeding control)

**No difference in pain control when a vasoconstrictor is added.**

• **There is a difference in amount of bleeding.**

• **The most hemostasis requires use of a 1:50,000 dilution.**

Allergic reactions associated with topical are very rare but do exist.

**Allergic reactions can occur up to 2 days after the anesthetic is given.**

o **Topicals are generally of a higher % to aid diffusion through the mucous membrane.**

What does oraqix gel contain?

2\.5% Prilocaine and 2.5% Lidocaine anesthesia intraoral.

No pulpal anesthesia, only SOFT TISSUE

Onset of action: 30 seconds

Duration: Approx 20 minutes

Lidocaine as a topical

Most common in a ointment (gel form)

Available in 2 forms

Base-better because it is not water soluble so stays where you place it

Hydrochloride salt- Water soluble and absorbs easily so has greater chance of systemic toxicity

Benzocaine as a Topical an Ester

Most Common and widely used

Used in a 20% concentration

The onset is rapid and peak of effect as 30 seconds

Duration is 5-15 minutes

Can one concentration of anbesol be used safely for every member of the family?

No one Anbesol cannot be safely used for every member of the family because it comes in a variety of strengths

How can allergy to topicals occur?

Either quickly or up to 2 days after application

The most common type of topical is in what form

Lidocaine topical as a gel

Articaine (septocaine)

Do not use a 4% anesthetic in the Inferior alveolar injection IA

The elimination is 1/2 life only 27 minutes so the anesthetic is 97% out of the system in approx 2 1/2 hours

4% Articaine with epi 1:100,000 or

4% Articaine with epi 1:200,00

Topical uses of Prilocaine

Oraqix:

2\.5% lidocaine and 2.5% Prilocaine gel to numb soft tissue (pockets) but does not numb the tooth

What anesthetic is a good choice for a patient with a history of a true bisulfite since there is no vasoconstrictor which contains sodium bisulfite

4% Prilocaine or 3% MepivacaineQ

What is great choice for a patient with cardiovascular disease because since the 1:200,000 dilution is half as potent as the 1:100,000 dilution, the patient receiving a cardiac dose can now receive 4 cartridges instead of only 2 of 2% Lidocaine w/1:100,000.

4% Prilocaine w/1:200,000

Prilocaine (Citanest) is metabolized in what 3 places

Liver, lungs and kidneys

Mepivacaine (carbocaine, Polocaine)

Has the least vasodilatory properties so works well if the patient Can’t have vasoconstrictor

Metabolized in the liver

2 formulations: 3% Mepivacaine plain and 2% Mepivacaine with LEVONORDEFRIN 1:20,000

They only use Levonordefrin in the us

Lidocaine (Xylocaine)

The most used anesthetic in the US today

Metabolized in the Liver

Lidocaine is available in 2 different forms 2% lido with epi 1:50,000 or 2% lido with epi 1:100,000

It has anticonvulsant properties and can be used to treat seizures

Pts may experience slight sedative effect compared to others

What is the name of the vasoconstrictor, commonly combined with 3% prilocaine, that may be safely administered to patients with uncontrolled hyperthyroidism?

Felypressin

Which is a vasoconstrictor usually combined with 3% prilocaine and used for patients taking tricyclic antidepressants or MAO inhibitors because it has very little effect on the myocardium or adrenergic nerve transmission

Your patient indicates on her health history that she is allergic to novocaine and sulfa drugs. What patient education might you provide to your patient?

Explain that novocaine is in the ester family of drugs and is known to cause allergic reactions. Instead, you will be using a local anesthetic from the amide family.

Which receptors relax bronchial smooth muscles, causing the bronchi of the lungs to dilate?

Beta 2 receptors

All of the following are absolute contraindications for the use of epinephrine EXCEPT one. Which one is the EXCEPTION?

Recent Knee replacement

Ones that are contradictions are Unstable angina, uncontrolled diabetes, and uncontrolled hypertension

Adrenalin comes in dilutions of 1:50,000, 1:100,000, and 1:200,000.

True

Adrenalin is also known as epinephrine

Undesirable side effects of incorporating sympathomimetic agents such as epinephrine into local anesthetic solutions include

Increased rate and force of heart contractions

What is the solution that was added to the cartridge of local anesthetic to prevent bacterial growth?

Methylparaben

Sodium bisulfite is added to the cartridge with anesthetic with a vasoconstrictor to prevent oxidation of the vasoconstrictor

Sodium hydroxide acts as a buffer to adjust pH

Which amide anesthetic agent is metabolized by the lungs before it reaches the liver?

Prilocaine

Which is an amide

Local anesthetic agents with vasoconstrictors are generally more acidic than plain formations because of the presence of sodium bisulfite

Both the statement and reason are correct and related

Intermediate-action anesthetics are most commonly used for regular restorative dentistry and nonsurgical periodontal therapy.

True

Inflamed tissue experiences an increase in vascularity, slowing the onset of anesthetic action and decreasing the duration of anesthetic action; however, in healthy tissues the onset of action and the duration of action are more predictable.

True inflamed tissues

Mepivacaine is the most commonly used anesthetic in the United States.

False

Lidocaine is the most commonly used anesthetic

There are two main classifications of local anesthetic agents: esters and amides. Esters are metabolized in the liver, and most amides are metabolized in the plasma.

The first statement is true and the second is false

Esters in blood plasma and amide in liver

All of the following are considered advantages for the use of topical anesthetic agents EXCEPT one. Which one is the EXCEPTION?

The exception: Can be purchased over the counter \n The fact that topical anesthetic agents can be purchased over the counter is not necessarily an advantage when one considers the risk of toxicity. 

What is the most common topical preparation for lidocaine?

Ointment

While at room temperature, Oraqix is in gel form in the cartridge. It will liquidate as it reaches body temperature in the periodontal pocket

Both statements are false

While at room temp Oraqix is in liquid form in cartridge and it will gel as it reaches body temperature in the perio pocket

What is the name of a common ketone topical anesthetic?

Dyclonine Hydrochloride

Benzocaine topical anesthetic exists almost entirely in its base form causing a fast absorption into circulation.

False \n Correct: Benzocaine topical anesthetic exists almost entirely in its base form, making absorption into circulation low.

What is the available concentration of Oraqix

2\.5% lidocaine and 2.5% prilocaine

What is the main difference in the mechanism of action between topical anesthetics and injectable anesthetics?

Location of the blocking of nerve conduction

Topical anesthetics work by blocking nerve conduction at the surface of the skin or mucous membrane. Depolarization is decreased, and there is an increase of excitability threshold

A 1:100,000 dilution of epinephrine for obtaining pulpal anesthesia may be used in combination with a relatively small infiltrated dose of 1:50,000 to decrease bleeding. This is a particularly important strategy for dental hygienists to use during provision of nonsurgical periodontal therapy.

Both statements are true

Which of the following anesthetics are combined with Levonordefrin

2% Mepivacaine

How long do adverse effects of vasoconstrictors last in the body?

5 to 10 minutes

What is the maximum recommended dose of epinephrine per appointment for a health patient?

0\.2mg

Patients with a relative contraindication to vasoconstrictors can receive epinephrine containing local anesthetic agents in the lowest possible dose, not to exceed the MRD of 0.04 mg per appointment, using the best technique. In general, there are only a few absolute contraindications to the use of a vasoconstrictor, and in most situations limiting the amount of vasoconstrictor a patient can receive produces the benefits of vasoconstrictor use in local anesthesia without compromising the patient.

Both Statemtns are true,

Vasoconstrictor without compromising patient

Which anesthetic solution, no longer used in dentistry, is still available in multidose vials and is used in medicine as an antiarrhythmic agent?

Procaine

Increasing the pH of local anesthetic agents toward physiologic prior to injection is referred to as which of the following?

Anesthetic buffering

Septocaine, Zorcaine, and Articadent are the proprietary names for which of the following?

Articaine

What is the name of the only topical amide anesthetic currently on the dental market in the United States?

Lidocaine

Which of the following local anesthetics, without a vasoconstrictor, is/are useful in dentistry when the vasoconstrictor is contraindicated?

Prilocaine and Mepivacaine

Amide

What duration category best describes mepivacaine 3%?

Short acting

What is the name of a common ester topical anesthetic?

Benzocaine

To obtain the most benefit from the use of topical anesthetics, a fairly substantial amount of topical should be placed on the cotton tip applicator. This amount mixes with the saliva and may numb the tongue, soft palate, or pharynx.

The first is false and second true

What has the combined lidocaine/prilocaine cream been approved and effectively used for?

Medical procedures

What is the reason that concentrations of topical anesthetic agents are higher than those of their injectable counterparts?

They facilitate diffusion of the topical anesthetic agent through the mucous membrane

Neither topical nor injectable anesthetics used in dentistry are natural vasoconstrictors. With these higher concentrations and lack of vasoconstriction abilities, the risk of local and systemic absorption increases, thus increasing the risk of toxicity.

What inactivates epinephrine once it is in the bloodstream?

Adrenergic nerves

Which of the following vasoconstrictors are NOT added to dental local anesthetic drugs in the United States?

Phenylephrine

Felypressin

Norepinephrine

All options listed