Test 2- Pharmacology Flashcards
What is sympathomimetic
vasoconstrictors resemble the response of adrenergic nerves to stimulation (classified as adrenergic or sympathomimetic)
what are the functions of vasoconstrictors
- decrease absorption reducing toxicity and increasing duration
- smaller volumes of anesth
- increase efficency
- reduce bleeign
what are direct acting sympathomimetic amines*
exert action directly on adrenergic receptors (EPI)
- what are alpha receptors
smooth muscle in blood vessels.. constricts lumen
what are beta receptors*
smooth muscle relaxation (vasodilation and bronchodilation)
What is the most common vasoconstrictor
epi
what other vasoconstrictor is available in the US
levonorefrin in mepivicaine 1:20,000
- 1:100,000 has how much epi
1: 200,000
1: 50,000
.01 mg/ml
.005 mg/ml
.02 mg/ml
concentration of epi always refers to
1 mL
*how much epi is in one CARTRIDGE @ 1:100,000
3 CARTRIDGES?
.018
.054
what is the concentration of the vasoconstrictor in a 1:100,000 solution of lidocaine
.01 mg/ml
If 2 carps of 2% lido with 1:100,000 Epi are administered what is the quantitiy of epi
.036 mg
if 4 cartridges of .5% bupivicaine with 1:200,000 epi are administred what quantity of epi was given
.036 mg
What is the other name for epi
adrenalin
what is the important ingredient in the chemical structure of epe
sodium bisulfite
what does sodium bisulfite do
delays deterioration
what is the mode of action of epi
alpha and beta receptors
what happens in the myocardium with the use of eip
cardiac output and heart rate are increased
what happens to the coronary arteries with epi
produces dilation of the coronary artery
what happens to blood pressure with epi
systolic is increased and diastolic is decreased
there is a decrease in cardiac ________ with epi
efficency
What are the side effects of epi
CNS Stimulation, anxiety, fear, tension, restlessnes, throbing
What is the other name for Levonordefrin
neo-cobefrin
what is the mode of action for levonordefrin
alpha receptors, some beta
what factors should be considered when selecting a vasoconstrictor
- length of procedure
- need for hemostasis
- medical status of pt
how long does 2% lido without epi provide pulpal anesthesia for? with epi
10 min
60 min
what 4 conditions must be weighed for the use of a vasoconstrictor
- high blood pressure
- cardiovascular disease
- hyperthyroidism
- tx with MAOI and tricyclic antidepressants
what are absolute contraindications with tricyclics
levonordefrin and norepinephrine
What can 4 carps of LA with 1:100,000 epi stimulate
beta action stimulates glycogenisis
what is the rebound effect
bleeding postoperatively
a 2% lido with ph of 6.8 is changed to _____ with the addition of epi
4.2
What are the 2 effects of LA on blood vessels
Vasodilation (prilocaine)
vasoconstriction (cocaine)
what is the effect of vasodilation of LA
increase absorbtion, decrease duration and quality, increases potential for toxicity
what are the forms of LA
oral, topical, injection
what LA is the only on that works
cocaine
where are topical LA absorbed
in mucous membranes, not effective on intact skin
after injection of LA the rate of uptake is good but is related to
the vascularity of the inj site and vaso activity of drug
what organs have higher blood levels
highly perfuse
brain, liver, kidney, lungs, spleen
what contains the highest percentage of LA because of its mass
skeletal muscles
where does all anesthetic eventually go
the liver
what does the liver do to anesthetic
hydrolyses it
what has a significant bearing on the potential toxicity of a drug
the plasma concentration of LA
What are blood levels influenced by
- rate of adsorption in cardiovascular system
- rate of distribution
- elimination of drug
what is elimination half life
the time needed for 50% reduction in blood levels
75% for 2 half lives
ALL LA can cross what
blood brain and placental barrier
What are people usually allergic to with esthers?*
PABA
what is PABA?
what procaine/novacaine is hydrolyized to before excretion
Where are esthers used
outside of US, mexico, Japan
What is an example of an esther
procaine/novacaine
What are esthers hydrolyzed by in the plasma
pseudocholinesterase
What are all injectable dental anesthetics
amides
where are amides hydrolyzed
in the liver
when does pesudocholinesterase break down
as soon as it gets into the bloodstream which means its ability to work is bad
What is an absolute contraindicaiton
documented, repeatable allergy
what is a relative contraindication
SIGNIFICANT liver dysfunction, heart failure, renal disease, hypotension, CHF
-watch how much you give
What is the primary means of excretion of LA
kidneys
*LA are chemicals that:
reversibly block action potientials in all excitable membranes
how does LA act in the CNS
CVS
as a depressant
circumoral and lingual numbness
*what is the direct action of LA on the cardiovascular system
-direct action on myocardium is depression in general but more resistant than CNS
What is the primary effect of LA on bloodpressure
Hypotension
What is the effect of LA on the respiratory system at non overdose levels? overdose levels?
relaxant action
repiratory arrest
Is malignant hyperthermia a concern with LA*
NO
What LA has the greatest degree of protein binding
ones that have a longer duration of clinical activity
how is toxicity of LA manifested
gen. tonic clonic convulsion
