Pharmacology LECT Overview of CV Receptors and Drug Classes (Martin) Flashcards
(89 cards)
1
Q
norepinephrine
A
(alpha1 = alpha2, b1»b2)
sympathomimetic (agonist)
2
Q
epinephrine
A
a1 = a2, b1 = b2
non selective sympathomimetic (agonist)
3
Q
isoproterenol
A
b1 = b2»_space;»alpha
sympathomemetic agonist (mostly beta)
4
Q
what does sympathomimetics agonists mean?
A
mimics sympathetic nervous system activity
5
Q
phenylephrine
A
alpha selective agonist
alpha1> alpha 2»_space;»> Beta
6
Q
albuterol
A
B2 selective agonist
B2»B1»_space;»>alpha
used in asthma–> bronchiodilation
7
Q
dobutamine
A
B1 selectve agonist
B1>B2»_space; alpha
B1 is on heart
positive inotropic & some increase in rate
Cardiac output increases
little vascular effect
8
Q
Dopamine
A
Dopamine agonist
D1=D2»_space; B» alpha
renal
9
Q
Propranolol
A
Nonselectivce Beta adrenergic antagonist
B1 = B2»_space;> alpha
used to treat high blood pressure
10
Q
Atenolol and Metoprolol
A
B1»_space; B2
B1-selectice adrenergic antagonist
used to treat high blood pressure
11
Q
what is affinity of a drug
A
how tightly these drugs bind to the receptor
12
Q
what is the potency of the drug
A
how much drug it takes to activate the receptor
13
Q
Phentolamine
A
non selective alpha-adrenergic antagonist
a1 = a2
14
Q
Prazosin
A
alpha 1 SELECTIVE alpha adrenergic ANTAGonist
a1»_space;»a2
15
Q
Carvedilol
A
mixed antagonist (both alpha and beta blocking activity)
b1 = b2 ≥ a1 >a2
16
Q
3 Muscarinic cholinergic agonists
A
Acetylcholine (muscarinic and nicotinic agonist)
Bethanechol
Methacholine
17
Q
Bethanechol
A
muscarinic cholinergic agonist
M1-5»_space;»NM (nicotinic muscle) ,NN (nicotinic neuronal)
18
Q
Atropine
A
Muscarinic receptor antagonist
(M1 = M2 = M3»_space;»>NM,NN)
(blocks M1-M5!!)
Oral, Parenteral, Opthalmic
19
Q
what are 3 muscarinic receptor antagonists
A
atropine
ipratropium bromide (inhale)
Tiotropium (inhale only)
20
Q
what does dopamine cause in the kidney
A
vasodilation (renal vascular smooth muscle)
21
Q
what effect does blocking NET pump have?
A
blocks the ability of the reuptake of NE
22
Q
where is M1 receptors found
A
in nerves
IP3 and DAG
increase Ca
23
Q
muscarinic are what type of receptors?
A
metabotropic
excitatory and inhibitory
24
Q
what type of receptors are nicotinic receptors?
A
ionotropic
excitatory
25
where are M2 receptors
cardiovascular/heart
these cause Inhibition of cAMP production and activation of K+ channels
26
where are M3's found
glandular
IP3, DAG cascade leading to increased Ca
27
where are M4 and M5 found?
CNS
28
where are nicotinic muscular receptors ? what are they blocked by?
skeletal muscle
| blocked by curare
29
where are nicotinic neuronal?
| what are they blocked by
nerves
blocked by hexamethonium
30
alpha 1 on vascular smooth muscle do what when this receptor is activated?
Vasoconstriction
main regulator of blood pressure
31
is there parasympathetic innervation to blood vessels?
NO
32
are there muscarinic cholinergic receptors on blood vessels?
yes
but there is no nerve or signal there to release Ach so they aren't ever activated.
if you gave a bolus injection into the blood vessel of ACh you would get vasoconstriction, but it would last only about 2 seconds b/c there ACHesterase that would chew it up and destroy it
33
what do B2 receptors do for vasculature when they are activated?
cause relaxation of smooth muscle so vasodilation!
34
arteriole diameter is controlled by tonic release of what?
norepinephrine
35
what would happen if there was inhibition of medullary vasoconstrictor center?
decrease in sympathetic output and decrease in peripheral vascular resistance
36
what are the effects of alpha 1 receptor activation in the eye?
spleen?
uterus?
pilomotor muscle?
heart?
liver?
a1mydriasis (dilates pupil)
contraction of iris radial muscle
a1 contraction of spleen
a1 contraction of uterus
a1 contraction of pilomotor muscle (erects hair)
a1 increases force of contraction in heart
less important than b1 effect
liver--> glycogenolysis
37
what are the effects of alpha 1 receptor activation in the intestinal smooth muscle
hyperpolarization and relaxation
38
what happens when someone becomes hypoglycemic?
Sympathetics fire (alpha 1's) and release norepinephrine onto the liver causing glycogenolysis breaking down stored energy into glucose
39
what is the role of alpha 2 receptors mainly?
regulation of neurotransmitter release
these are presynaptic!!!
Autoreceptors” – NE activation of presynaptic a2 receptors decreases NE release from nerve ending.
these can also cause vasoconstriction but only is certain vascular beds and are of minor physiological significance
40
what does stimulation of B1 receptors do?
B1 receptors are most prominent and important in the heart
stimulation causes increase in heart rate
(chronotropic effect)
increased force of contraction
inotropic effect
41
```
what does activation of B2 receptors in the lungs do?
vasculature?
uterus?
bladder?
intestinal smooth muscle?
```
relaxation of bronchioles b2***
relaxation of vascular smooth muscle*** b2 (vasodilation, certain vascular beds only)
relaxation of uterus b2
relaxation of detrusor (bladder) b2
relaxation of intestinal smooth muscle b2
42
what would be beneficial for an asthmatic patient?
a beta-2 agonist
this is because in asthma the airways are constricted due to inflammation, so it is necessary to open up the airways! bronchiodilation
43
what does beta-2 receptor activation do in skeletal muscle?
stimulates potassium uptake
44
```
what are the metabolic and hormonal effects of beta receptor activation?
liver
fat cells
insulin
renin
```
glycogenolysis b2 (liver) (release of glucose from the liver)
lipolysis b3 (fat cells)
stimulation of insulin release b2
stimulation of renin release b1
45
when sympathetics fire, but is the effect on the kidney? what receptor?
D1
firing of sympathetics causes dilation
increases blood flow to the kidneys ***
so in the scenario of shock, you need good kidney flow!!! to maintain electrolytes in balance
46
how is selectivity different than specificity?
lets say something is B2 selective agonist
the selectivity means it is dose dependent and has higher potency/higher affinity at B2 than B1 but this does not mean we won't have any B1 effects!! because it is not SPECIFIC but rather SELECTIVE
47
what is chronotropic effect?
something to do with heart rate
48
what is inotropic effect
having to do with contraction of heart
49
what is epinephrines effect on the heart? (rate, contraction, conduction velocity)
positive chronotropic effect
positive inotropic effect
increased conduction velocity in atria, A-V nodes & purkinje fibers
***
the work of the heart is increased substantially
increased oxygen consumption
***
50
what is the effect of epinephrine during a heart attack? and how is this counteracted?
epinephrine would make things worse during a heart attack because it increases the oxygen consumption b/c the work of the heart is increased (increased contraction force, rate, and conduction velocity)
SO use a beta-blocker to slow the heart, decrease O2 consumption and work of heart
51
what is the effect of epinephrine on the blood vessels?
a1 vasoconstriction
b2 vasodilation
***Epinephrine is more potent at B2 than alpha 1
so at the lowest levels of Epi B2 will be on first and then as Epi rises, alpha 1 will be turned on
52
what predominates (alpha 1 or beta 2) at high doses of epinephrine?
vasoconstriction dominates
53
what is the distribution of alpha 1 and beta receptors in skeletal muscle?
both b2 and alpha 1
so it is DOSE DEPENDENT
first start to exercise--> have vasodilation (b2)
if you go into shock or really high stress now there is alot of epi --> vasoconstriction a1
54
what is distribution of alpha and beta receptors in coronaries?
vasodilation due to both B2 and metabolic (NO and adenosine)
55
what is distribution of alpha and beta receptors in the kidney, skin, mucosa?
mesenteric beds?
cerebral?
pulmonary?
primarily alpha 1 vasoconstriction
mesenteric--> both b2 and a1, density varies
cerebral--> unchanged
pulmonary --> vasoconstriction alpha 1
56
what is a vasopressor?
elevated blood pressure
so epi would be a vasopressor, used for vasoconstriction
57
what is asthma treatment in kids?
racemic epinephrine solution in a nebulizer for kids
opens up airways b/c of B2 activation
58
why is epinephrine not used in adults?
because it is too short acting
instead use Albuterol which activates B2 receptors selectively
59
```
what is epinephrines effects at smooth muscle?
lungs
GI
bladder x2
Spleen
Eye
Uterus
```
Bronchial smooth muscle relaxation b2
Opens the bronchial airways
GI-relaxation; slight decrease in muscle tone
Bladder
relax detrusor b2
contract sphincter a1
Spleen contraction
Eye - mydriasis, lowers IOP
Uterus - relax (b2) during last month of pregnancy
60
at which receptors is norepinephrine an agonist? at which receptors does it have very low potency ?
```
Agonist at a1, a2, a1 receptors
very weak (low potency) at b2 receptors**
```
61
what is the effect of norepinephrine on the heart?
direct: positive inotropic and chronotropic (B1)
indirect: reflex bradycardia (blocked by atropine) muscarinic cholinergic blocker
net effect: increase force; decreased rate
slow, forceful heartbeat***
62
what is norepinephrines effect on blood vessels
alpha 1 mediated vasoconstriction which causes an increase in BP
63
what is norepinephrines use in anesthesia?
used as a pressor in spinal anesthesia when all autonomic control has been turned off so anesthesiologist can titrate BP and HR with NE
64
where is isoproternol an agonist
what are the effects of Iso on heart
on blood vessels?
B receptors
NO alpha effects
Heart b1 increased heart rate and force
```
Blood vessels:
B2 vasodilation in skeletal muscle & mesentery
decreased diastolic BP
increased systolic BP
no change or decreased mean BP
```
65
What are dopamines receptors
D1
Beta 1
alpha 1
66
what are the pharmacological effects of dopamine
on blood vessels (high and low doses)
heart
blood vessels--> low does vasodilates renal and mesenteric (D1 receptors) increases blood flow to the kidney ***
at mildly high doses heart--> mild increase in rate and force because it is a partial agonist of B1
at even higher doses doses blood vessels--> causes vasoconstriction and increased BP (alpha 1)
this is because dopamine is related in structure to epi and NE
67
what happens in cardiogenic shock and what can be done about it?
weak heart and not efficient in pumping and not providing enough blood flow and oxygenation
and this includes blood flow to the kidneys and electrolytes get screwed up!
So give patients a low drip rate of dopamine to increase blood flow to kidney
increase the drip a little bit more ... now kicking in B1 for better CO, more forceful contraction and rate
even higher drip rate would kick in alpha receptors, which is NOT good b/c there is already very intense vasoconstriction in the periphery
***so must titrate just right
68
what is the clinical use of dobutamine
what are the adverse effects>
MI, CHF, cardiogenic shock
Adverse effects: may increase size of infarct
potential arrhythmias
69
what is the use of alpha 1 adrenergic agonists
pressor agents to increase BP
70
what is phenylephrine
vasoconstricts the nasal mucosa
DECONGESTANT
doing alpha 1 mediated vasoconstriction because it is a alpha1 adrenergic agonist
Vasoconstriction nasal mucosa/ decongestant
(pressor agent) increase peripheral resistance; increase BP
increased blood pressure causes reflex bradycardia (blocked by atropine-muscarinic blocker)
71
what is the main use of B2 selective agonists
used to treat asthma
72
what is albuterol
what are its side effects
relatively selective b2 (10x) agonist
bronchodilation
used for treated bronchospasm in asthma
aerosol delivery - restricts to lungs, decreases systemic absorption and side effects
Oral - sometimes used, more side effects when oral
Side effects:
muscle tremors, tachycardia (B1 and reflex), anxiety, restlessness, headache, hypoglycemia, hypokalemia
73
what is the difference in effects of propranolol in a person that is resting or someone who is exercising.
in a person who is resting there is not going to be much sympathetic tone (because rest and digest is going to be predominating)
SOOOO.... there is going to be a much greater effect in someone who is exercising or under alot of stress
74
what are the pharmacological effects of propanolol?
decrease heart rate and cardiac output b/c blocking beta 1
decrease exercise tolerance
decrease rate of depolarization of ectopic pacemakers
Clinical --> cardiac arrhythmias, MI
Decrease work of the heart and decrease O2 demand*** MOST IMPORTANT
decrease AV nodal conduction (can produce AV block)
decrease infarct size & re-infarction- prevent sudden death
75
what is an absolute contraindication to using nonselective beta blocker *** know
COPD and asthma patient
b/c these people already have constricted airways and are using B2 to keep them vasodilated
so you can't block their B2 stimulation b/c it would make their breathing worse
ALSO DIABETICS b/c it masks the signs of hypoglycemia (which are usually sympathetic output like tachycardia, bp changes)
76
what are B1 selective blockers used for? clinically
more potent at B1 than B2
at higher doses block B2 as well
lessen the risk of bronchospasm and are preferred in people with diabetes because it they usually do not prolong hypoglycemia
still contraindicated in asthmatic
77
what are two examples of B1 selective blockers
Atenolol
| Metoprolol
78
what is Carvedilol (Coreg)
Nonselective B blocker and alpha blocker
Very lipid soluble
Decreases mortality by 65 percent in CHF clinical trials
slows the heart!! so it has to work less hard and uses less O2 and ATP most likely
79
what is the parasympathetic effect (using muscarinic Ach receptors) on extravascular smooth muscle ...
Bronchials
GI
Urinary bladder
Eye muscle
Bronchial smooth muscle contraction
GI--> increased tone and motility
Urinary bladder: contraction of detrusor, contraction (opening) of trigone and sphincter
Eye muscle: miosis via iris sphincter accommodation via ciliary muscle contraction
80
what is the sympathetic effect on the eye
mydriasis (contraction of the radial muscle, iris)
dilates the pupils (alpha 1)
relaxes the ciliary muscle (B2)
81
what is the parasympathetic effect on the eye
contraction (miosis) of the sphincter muscle of the iris (M3)
contraction of the ciliary muscle (M3)
82
atropine is what... what does it do for the heart and vasculature
an antagonist of muscarinic receptors
so it reverses bradycardia by stopping the parasympathetic input to the heart (M2)
vasculature--> no direct effect b/c there is no parsympathetic innervation to vasculature
83
Ipratropium
Muscarinic antagonist
used to treat asthma COPD (drug of choice) b/c it blocks the constriction that parasympathetic muscarinic receptors cause
84
Tiotropium
```
muscarinic antagonist (inhalation)
used to treat COPD and asthma
```
longer acting than Ipratropium
85
what is combivent
albuterol + ipratropium bromide
86
b2
vasodilation
causes subsequent drop in blood pressure which means decreased rate of baroreceptor firing, leading to decrease parasympathetic output and increased sympathetic output --> Increase HR
87
alpha 1
vasoconstriction
causes increase in blood pressure and baroreceptor firing leading to increase in parasympathetic output and decreased sympathetic output meaning DECREASE HR
88
muscarinic
decrease in heart rate b/c muscarinics usually cause vasoconstriction
89
b1
stimulation of heart rate and force (increase)
