Part 4-Vasoconstrictors!

Question 1

What are the 2 vasoconstrictors in dental LAs?

Answer 1

epinephrine and LEVOnorDefrin

Question 2

What are the two parts to a “catechcolamine”

Answer 2

1.catechol = OH substitutions on an aromatic ring 2.amine = NH2 group attached to the allopathic side chain

Question 3

What are the three categories for Vasoconstrictor modes of action>?

Answer 3

1.direct 2.indirect 3.mixed

Question 4

What are the UNITS for our vasoconstrictor RATIO in the Rx ?

Answer 4

grams of drug : milliliters of solvent….1 gram epi : 100,000 mililiters of solvent

Question 5

What is the highest does of epi out there? (found in epi pen)

Answer 5

1: 1,000

Question 6

What are the UNITS for vasoconstrictor we use AT SCHOOL?

Answer 6

mg/ml…SO 1 g epi :100,000 ml solution in SCHOOL terms is 0.01mg/ml (haha ok, took me a while, but I think I’ve got it :)

Question 7

What is the ONLY LA that contains LEVO-NOR-DEF-RINE?? What is the mixture?

Answer 7

ME-PIV-A-CAINE….2% (brown) so 1:20,000 or in ASDOH units 1000mg/20,000ml = 0.05mg/ml

Question 8

Elevation of plasma levels of epinephrine is linearly _____ dependent and persists from several minutes to an hour

Answer 8

dose

Question 9

When do peak levels of epi reach the plasma?

Answer 9

5 minutes post infection

Question 10

________mimetic effects will be evident 􏰀 “epinephrine reaction” Anxiety/apprehension, Tachycardia, Sweating, Palpitations

Answer 10

Sympatho

Question 11

FREAKING KEY: What is the antioxidant used to PRESERVE the epinephrine in a LA solution??????

Answer 11

Sodium Bisulfate-allegry source

Question 12

Even though Epi directly acts on alpha AND beta receptors, what does it predominate?

Answer 12

BETA

Question 13

BETA 1 effects?

Answer 13

Increase HR, Force, SV, and therefore CO

Question 14

BETA 2 effects?

Answer 14

DILATION of coronary arteries, airway, skeletal muscle arteries

Question 15

Interesting…in SMALL doses epi primarily effects ____ receptors VS LARGE doses epi primarily effects _____ receptors

Answer 15

SMALL-alpha (constriction)….LARGE-beta (dilation)

Question 16

Confusing: Epi effect on BP—-Systolic BP does what and Diastolic BP does what (at small dose)

Answer 16

Systolic BP = increases….diastolic (small) = decreases

Question 17

Epi and hemostasis: initially works well on _____ receptors, giving the “white as a ghost”, but then its _____ receptor effects show through after about 6 hours with oozing bleeding

Answer 17

alpha….beta 2

Question 18

What effect does epi have on the CNS at therapeutic doses?

Answer 18

NONE!!! won’t get CNS stimulation until there are OD levels of epi present

Question 19

Why must we be careful giving epinephrine to DIABETICS? How many cartridges will give us this affect?

Answer 19

Epi causes an increase in BLOOD SUGAR!!! about 4 cartridges to have this effect

Question 20

What is the main molecule that deactivates endogenous EPI? What about exogenous (dental) epi?

Answer 20

MAO….exogenous: COMT (catechol-O-methyltransferase

Question 21

In a healthy patient the MAXIMUM safe dosage of Epi is __mg (____mcg)

Answer 21

0.2mg…(200mcg)

Question 22

With ASA III or greater Pt what is the max Epi dose in mg?

Answer 22

0.04mg (0.2mg for healthy pt…BIG difference!)

Question 23

QUICK! What is the amount of Epi in mg for these three [ ]’s: 1) 1:50,000 2) 1:100,000 3) 1:200,000

Answer 23

1) 1:50,000 = 0.02mg (20mcg) 2) 1:100,000 = 0.01mg (10mcg) 3) 1:200,000 = 0.005 mg (5mcg)

Question 24

Which epi dilution should be the “dilution of choice? in at risk individuals?

Answer 24

1:100,000

Question 25

What is added to LevoNorDefrine to preserve it?

Answer 25

Sodium bisulfide (again) :)

Question 26

Which receptor does levonordefrine primarily act on (75%), what about the other 25%?

Answer 26

75%-alpha receptors…25%-beta

Question 27

How potent is levonordefrine compared to epi?

Answer 27

15% as potent!!! (3/20’s!!)

Question 28

Since levonordephrine is so much less potent than epi, what do we have to do to the preparation?

Answer 28

increase its [ ] !!! (1:20,000 or 0.05mg or 5%)

Question 29

Termination/elimination of levonordephrine: which enzyme that natural epi uses is not used here? Which enzyme IS?

Answer 29

MAO not used…but COMT (catechol-O-methylTransferase)

Question 30

For healthy Pt’s MAX dose of Levonordefrine is __mg/appointment….. 20ml of 1:20,000 = ___ cartridges

Answer 30

1mg/appointment….11 cartridges

Question 31

For cardiac compromised patients the cardiac dose of levonordefrine is ___mg…4ml of 1:20,000 = ___ cartridges

Answer 31

0.2 mg….2 cartridges

Question 32

What technique helps make sure we do not directly inject anesthetic or epi into CVS?

Answer 32

aspiration