Lecture 7 - autonomic pharmacology 1

Question 1

what does cAMP inhibit

Answer 1

myosin light chain kinase

Question 2

what are the anatomic locations of alpha-1 receptors

Answer 2

1. vascular smooth muscle
2. iris
3. urinary tract sphincters
4. GI smooth muscle
5. CNS

Question 3

what are the anatomic locations of alpha-2 receptors

Answer 3

1. blood vessels
2. glands
3. GI tract
4. eyes/CNS
5. platelets

Question 4

describe the properties of alpha-adrenergic agonists. give examples

Answer 4

• naturally occurring and synthetic
• evoke responses of the SNS

ex: epinephrine, norepinephrine, phenylephrine, ephedrine

Question 5

T/F: the selectivity of a drug can be dose-dependent

Answer 5

TRUE

Question 6

what are the 4 general uses of alpha-1 agonists

Answer 6

1. vasoconstriction
2. treat anaphylaxis
3. manage urinary incontinence
4. mydriasis

Question 7

classify epinephrine

selective or non-selective?
common uses?
routes of administration?

Answer 7

1. non-selective (all alpha and beta receptors)
2. CPR, anaphylactic shock, local anesthetics
3. IV, interosseous, intratracheal, topical

Question 8

a high dose of epinephrine will cause

Answer 8

vasoconstriction at A1

Question 9

T/F: epinephrine is the preferred drug to use as a local anesthetic for tail or digit amputations due to its vasoconstriction properties

Answer 9

FALSE - can cause tissue necrosis

Question 10

a low dose of epinephrine will cause

Answer 10

vasodilation at B2

Question 11

what cardiac effects can be seen by epinephrine usage

Answer 11

increased heart rate and force of contraction

may result in VPCs or V-fib

Question 12

classify norepinephrine

selective or non-selective?
common uses?
routes of administration?

Answer 12

1. selective for alpha effects (will bind B1)
2. manage hypotension under anesthesia
3. IV, infusion

Question 13

do we need to give a loading dose of norepinephrine? why?

Answer 13

No - short half-life will reach a steady state quickly

Question 14

classify dopamine

selective or non-selective?
common uses?
routes of administration?

Answer 14

1. dose-dependent selectivity
2. hypotension under anesthesia
3. infusion

Question 15

T/F: dopamine formulations are made to last long periods

Answer 15

FALSE - has a short half-life and formulations do not have preservatives

Question 16

what is the most selective alpha-1 agonist

Answer 16

phenylephrine

Question 17

classify phenylephrine

selective or non-selective?
common uses?
routes of administration?

Answer 17

1. most selective
2. increase BP, nasal edema tx, nephrosplenic entrapment (vasoconstriction)
3. topical, infusion

Question 18

what are the s4 ide effects of phenylephrine

Answer 18

1. tissue/organ damage from decreased blood flow
2. hypertension
3. reflex bradycardia
4. arrhythmias

Question 19

at low doses, dopamine binds _____ receptors

Answer 19

dopaminergic

Question 20

at medium doses, dopamine binds ____ receptors

Answer 20

beta

Question 21

at high doses, dopamine binds ____ receptors

Answer 21

alpha

Question 22

what alpha agonist crosses the blood-brain barrier

Answer 22

ephedrine

Question 23

classify ephedrine

selective or non-selective?
common uses?
routes of administration?

Answer 23

1. mixed (direct and indirect)
2. maintain BP, decongestant, bronchodilation
3. oral

Question 24

what are the direct effects of ephedrine

Answer 24

a1 and beta receptor binding

Question 25

what are the indirect effects of ephedrine

Answer 25

increase NE release

Question 26

what are the side effects of ephedrine use

Answer 26

1. hypertension 2. arrhythmias 3. urinary sphincter contraction 4. CNS stimulation

Question 27

define sympatholytic

Answer 27

blocks actions of the sympathetic nervous system

Question 28

what are alpha-1 antagonist drugs?

Answer 28

1. phenoxybenzamine 2. prazosin

Question 29

T/F: phenoxybenzamine binds irreversibly to receptors

Answer 29

TRUE

Question 30

classify phenoxybenzamine selective or non-selective? common uses? routes of administration?

Answer 30

1. non-specific 2. hypertension, urinary retention 3. oral (needs compounding)

Question 31

pheochromocytoma

Answer 31

malignant, functional adrenal tumor that increases epi/norepi

Question 32

under what conditions will phenoxybenzamine be avoided

Answer 32

if the patient is at risk for hypotension, going into systemic shock, or CHF chronic use may be avoided with patients with preexisting kidney disease

Question 33

T/F: phenoxybenzamine can cause hypotension and reflex tachycardia under anesthesia

Answer 33

TRUE

Question 34

classify prazosin selective or non-selective? common uses? routes of administration?

Answer 34

1. more selective for A1 2. oral 3. vasodilation (uncontrolled hypertension), smooth muscle relaxation

Question 35

what organs will be affected in uncontrolled hypertension

Answer 35

1. brain 2. kidneys 3. eyes 4. heart

Question 36

what precautions should be taken with prazosin use

Answer 36

- caution with chronic renal failure (hypotension will decrease flow to kidneys) - bradycardia possible due to decreased sympathetic outflow - CNS effects

Question 37

what drug blocks NE uptake and storage to "calm" equine patients

Answer 37

reserpine