Pharmacology of Vasoconstrictors

Question 1

Most anesthetics are vasodilators that have what kind of effect on the rate of absorption?

Answer 1

Vasodilators increase the rate of absorption

Question 2

Vasodilators have what effect on local anesthetic concentration in the tissue?

Answer 2

vasodilators decrease the concentrations of local anesthetics in the tissue.

Question 3

What is the overall effect of vasodilators in local anesthesia?

Answer 3

vasodilators shorten the duration of action and decrease the depth of anesthesia

Question 4

Vasodilators cause an _________ in surgical bleeding

Answer 4

increase

Question 5

What two anesthetics are weak vasodilators?

Answer 5

Prilocaine and Mepivacaine

Question 6

Vasoconstrictors in anesthesia act as a what?

Answer 6

chemical tourniquet

Question 7

List the 3 benefits of using vasoconstrictors in anesthesia.

Answer 7

-Increases the duration of anesthesia (smaller required doses of anesthesia)
-Increases the depth of anesthesia (less pain for the patient)
-Decreases systemic toxicity of anesthetic (reduces the peak plasma levels)

Question 8

True or false: A higher dose of epinephrine in local anesthetic is always better

Answer 8

false

Question 9

What are the two vasoconstrictors on the market used with local anesthetics?

Answer 9

epinephrine
levonordefrin

Question 10

What does sympathomimetic mean?

Answer 10

mimics the sympathetic nervous system “fight or flight” response

Question 11

Adrenergic drugs are classified based on the presence or absence of ________

Answer 11

a catechol nucleus

Question 12

What is the catechol nucleus?

Answer 12

ortho-dihydroxybenzene ring

Question 13

sympathomimetic drugs have OH substitution on what positions of the aromatic ring?

Answer 13

3rd and 4th

Question 14

what are the 3 natural catecholamines found in the sympathetic nervous system?

Answer 14

Epinephrine
Norepinephrine
Dopamine

Question 15

What are the 2 synthetic catecholamines?

Answer 15

Levonodefrin
Isoproterenol

Question 16

the preganglionic nerve of the sympathetic nervous system is short or long?

Answer 16

short

Question 17

the synapse of a preganglionic nerve in the sympathetic nervous system is located where?

Answer 17

within the ganglion residing along the spinal cord

Question 18

postganglionic fibers in the sympathetic nervous system are long or short?

Answer 18

long

Question 19

preganglionic fibers in the parasympathetic nervous system are long or short?

Answer 19

long

Question 20

where do postganglionic fibers in the sympathetic nervous system synapse?

Answer 20

directly on the end organ (typically an adrenergic receptor)

Question 21

preganglionic fibers in the parasympathetic nervous system are long or short?

Answer 21

long

Question 22

where does the synapse of long preganglionic Parasymp nerves synapse?

Answer 22

in ganglia residing outside of the spinal cord

Question 23

the postganglionic nerve fiber in the parasympathetic nervous system is long or short?

Answer 23

short

Question 24

where does the postganglionic nerve fiber of the parasymp. nervous system synapse?

Answer 24

on a cholinergic or acetlycholine receptor in an end organ

Question 25

where are alpha 1 andrenergic receptors located and what do they cause?

Answer 25

in the blood vessels causing vasoconstriction

Question 26

what effect do alpha 1 receptors have on the pancreas?

Answer 26

inhibits insulin secretion

Question 27

what effect do alpha 1 receptors have on the intestine and bladder?

Answer 27

relaxation and constriction of sphincters

Question 28

where are alpha 1adrenergic receptors located relative to the synapse?

Answer 28

on the postsynaptic side of the synapse (blood vessels/effector cells)

Question 29

where are alpha 2 adrenergic receptors located relative to the synapse?

Answer 29

located postganglionic fibers on the presynaptic terminal

Question 30

when the alpha 2 receptor on the postganglionic fiber is stimulated what is the effect?

Answer 30

inhibits the release of norepinephrine from the presynaptic terminal

Question 31

where are Beta 1 adrenergic receptors mainly found?

Answer 31

on the heart muscle (postsynaptically)

Question 32

what occurs when beta 1 receptors are stimulated?

Answer 32

increase in heart rate, contractility, and conduction velocity

Question 33

where are beta 2 andrenergic receptors located?

Answer 33

in the bronchioles of the lungs

Question 34

what effect occurs on the bronchioles when beta 2 receptors are stimulated?

Answer 34

dilation

Question 35

what effect occurs to blood vessels when beta 2 receptors are stimulated?

Answer 35

skeletal and coronary vasodilation

Question 36

what are the two ways that termination action occurs with epinephrine?

Answer 36

reuptake of epinephrine back into the adrenergic presynaptic terminal absorption into the blood stream

Question 37

what percentage of secreted epinephrine is brought back via reuptake mechanisms or metabolized by monoamine oxidase ?

Answer 37

80%