Adrenergic Blockers Flashcards
1
Q
Adrenergic β- Blockers have what result on ⍺ responses?
A
⍺ processes become dominant
reverse true for ⍺-Blockers?
2
Q
Normal result of ⍺1 stim?
A
Excitatory: mydriasis (C radial mm) C bv to skeletal mm, skin C hold urine ejaculation
3
Q
Normal result of ⍺2 stim?
A
Inhibitory:
↓ NE release
↓ insulin secretion
R GI
4
Q
⍺1-Blockade causes?
A
(Decreased vasoconstriction) ↓ peripheral resistance -> ↓ BP ↓ venous return (ortho/standing hypoTN) Miosis Nasal congestion ↑ urine flow (tx BPH) ↓ ejaculation
5
Q
⍺2-Blockade causes?
A
↑ NE release
↑ insulin release
6
Q
Normal results of β1 stim?
A
Inhibitory:
↑ renin
↑ HR, cond, contr
7
Q
Normal results of β2 stim?
A
Inhibitory: R bronchioles R bv in skeletal mm R coronary/cerebral arteries (↑ HR, cond, contr) R GI/U ↑ glycogenolysis/genesis
8
Q
Normal results of β3 stim?
A
Inhibitory:
↑ lipolysis
9
Q
β1-Blockade causes?
A
↓ renin
10
Q
β2-Blockade causes?
A
Bronchoconstriction
↓ rate/force contraction = ↓ CO, ↓ O2 demand
↓ IO pressure
↓ glycogenolysis
11
Q
β3-Blockade causes?
A
↓ lipolysis
12
Q
Competitive ⍺ agonsists shift dose-response curve?
A
Right (need more NE to cause effect)
Max effect is same
13
Q
Competitive ⍺ agonsists duration dependent on? (2)
A
dissociation from receptor
1/2 life
14
Q
Irreversible ⍺ agonsists shift does-response curve?
A
Right
Max response diminished
15
Q
Irreversible ⍺ agonsists duration dependent on?
A
exceed 1/2 life (stays bound)
16
Q
Reflex tachycardia results from ⍺-Blockade why? (2)
A
1) ↓ BP -> stim baro -> stim sypathetics (↓ vagal input)
2) ⍺2 block -> ↑ NE release -> ↑ β heart stim
17
Q
Ortho HTN results from ⍺-Blockade why?
A
⍺1 block = ↓ vasoconstriction of veins
↓ contraction -> ↓ filling pressure -> ↓ BP
18
Q
EpiNE reversal of ⍺-Blockade?
A
blocked ⍺ exposes β:
Epi dilates bv to skeletal mm ->
↓ BP -> reflex ↑ HR
19
Q
Phentolamine (Regitine) affects what receptors?
A
⍺1 and ⍺2
20
Q
Phentolamine effects on ⍺1?
A
(⍺-block)
↓ peripheral resistance -> ↓ BP
21
Q
Phentolamine effects on ⍺2?
A
(⍺-block)
↑ NE = ↑ baro -> cardiac stim (β)
22
Q
Phentolamine side-effects?
A
HypoTN
Tachycardia
Arryth
myocard ischemia
23
Q
Phentolamine used to tx?
A
HTN from pheonchromocytoma or MAO inhibitors
necrosis post ⍺-agonist infusion
24
Q
Phentolamine contraindicated for?
A
CAD peptic ulcers (stims histamine = acid prdxn)
25
Phenoxybenzamine affects what receptors?
IRREVERSIBLE ⍺-block
26
Phenoxybenzamine effects on ⍺ receptors?
(lasts several days)
↓ BP -> reflex tachycardia
⍺1 block = ↓ vasoconstriction -> ortho hypoTN
⍺2 block = inhibit NE reuptake
27
Phenoxybenzamine side-effects?
tachycardia
ortho hypoTN
nasal congestion
↓ ejaculation
28
Phenoxybenzamine used to tx?
pheochromocytoma (high symp tone),
| irreversible binding prevents HTN
29
Phenoxybenzamine contraindicated?
hypovolemic,
alcohol use,
vasodilators
= severe hyopTN
30
Pheochromocytoma is?
adrenal neoplasm:
| releases NE/Epi
31
Pheochromocytoma signs/sxs?
tx?
sudden-onset severe HTN, tachycardia, arrhy
Phenoxybenzamine
surgery
32
Prazosin affects what receptors?
⍺1 antagonist
33
Prazosin effects on ⍺1?
relax artery/vein smooth mm ->
↓ peripherial resistance,
↓ venous return/preload
no effect on ⍺2 means:
No ↑ CO
No tachycardia reflex
No NE increase
34
Prazosin administered?
1/2 life?
orally
3 hrs (doubles if CHF)
35
Prazosin side-effects?
1st dose phenom:
ortho hypoTN/syncope 90 mins post dose
nasal congestion
ortho hypoTN, esp w/ viagra
36
Prazosin used to tx?
HTN
| BPH
37
Other drugs similar to Prazosin?
Terazosin, Doxazosin
longer 1/2 lives = once daily dose
38
Tamsulosin (Flomax) affects what receptors?
(Antagonist)
⍺1A (prostate)
⍺1B (bv)
has very little effect on BP
39
Tamsulosin used to tx?
BPH (relaxes urinary sphincter)
low BP effects makes good alternate is "zosins" cause ortho hypoTN
40
Yohimbin affects what receptors?
Causes?
⍺2 antagonist
↑ NE release (CNS/periphery) ->
↑ symp tone -> ↑ BP and HR
41
Yohimbin used for?
"natural" viagra
42
Yohimbin contraindications?
interferes w/ Clonidine
| pts w/ HTN
43
Short term β-Block vs long term β-block effect on BP?
short = ↑ BP
long = ↓ BP
44
Effect of exercise/stress on HR when taking β-Block?
HR can't ↑ as much
45
β-block effect on EpiNE?
↑ pressor effect (vasoconstriction/↑ BP) due to block of 2 dilators
**don't give for pheochromocytoma w/o ⍺-block too
46
Danger of β-block effect on glycogenolysis?
↓ glycogenolysis masks and impairs tx of hypoglycemia
47
Propranolol (Inderal) affects what receptors?
β1 and β2
| competitive antagonist
48
Propranolol effects on β1 and β2?
```
competitive antagonist:
↓ HR, force, conduction
↓ renin
↓ glycogenolysis
↓ lipolysis
local anesthetic
```
49
Propranolol administered?
Metabolized by?
Soluble to CNS?
oral but variable 1st pass metabolism (wide dosage)
liver
yes
50
Propranolol used to tx?
```
↓ mortality from MI
Angina (↓ O2 demands)
Obstructive cardiomyopathy (antiarrhythmic)
Early CHF
Migraine
stage fright
```
51
Propranolol side-effects?
```
Bronchoconstriction (ø asthma or COPD)
Bradycardia
Abrupt disuse -> arrhythmia (up-regulated β rec)
Worsen Late CHF
sedation, depression (CNS)
```
52
Propranolol drug interactions?
drug that inhibit P450 = ↑ hypoTN
(Cimetidine, chlorpromazine)
drug that speed metabolism = ↓ effectiveness
(smoking, barbituates, rifampin)
Ca2+ channel blockers = additive effect
53
Timolol affects what receptors?
all β
| antagonist
54
Timolol primary use?
treat glaucoma
55
Timolol caution?
absorbed systemically so ø asthmatics
56
Nadolol affects what receptors?
all β
| antagonist
57
Nadolol benefits over other non-specific β-blokers?
no CNS penetration
no local anesthesia
less variability of absorption
long-acting
58
Sotalol affects what receptors?
all β
| antagonist
59
Sotalol benefits over other non-specific β-blokers?
blocks K+ channels
no local anesthetic
antiarrythmic
60
Effects of β1-selective Antagonists w/o Intrinsic Sympathetic Activity?
Mostly heart:
| ↓ HR, force
61
Benefits of β1-selective Antagonists w/o Intrinsic Sympathetic Activity?
ø block of bv dilation in skeletal mm = better exercise tolerance
less inhibition of glycogenolysis = ↓ hypoglycemia risk (safer for DM)
62
β1-selective Antagonists w/o Intrinsic Sympathetic Activity use to tx?
HTN
Migraine prophylaxis
Post MI >> life
Glaucoma (Betaxolol only)
63
β1-selective Antagonists w/o Intrinsic Sympathetic Activity side-effects?
bradycardia
hypoTN
(P) develop DM II
C/I asthmatics, COPD
64
β1-selective Antagonists w/o Intrinsic Sympathetic Activity drugs? (3)
```
Metroprolol (Lopressor)
Atenolol (Tenormin)
Bisoprolol (Zebeta)
Betaxolol (Betoptic)
Nebivolol (Bystolic)
Esmolol (Brevibloc)
```
65
Benefits of Nebivolol over other β1-selective Antagonists w/o Intrinsic Sympathetic Activity drugs?
↑ NO release from endo cells = vasodilator,
MOST selective for β1,
↓ arterial BP w/o depressing LV fxn,
Better ↓ of central aortic pressure,
Signification ↓ cholesterol, trigly, glucose
Fewer s/e
66
Benefits of Esmolol over other β1-selective Antagonists w/o Intrinsic Sympathetic Activity drugs?
Very short duration (1/2 life 8 min)
IV
Use for urgent need for rapid effects
67
Intrinsic Sympathetic Activity (ISA) means what?
PARTIAL AGONIST activity:
stim receptors when symp activity low,
reduce effects when NE/Epi is high
68
β-NON-selective Antagonists with Intrinsic Sympathetic Activity (ISA) drugs?
Pindolol (Visken)
Carteolol (Cartrol)
Penbutolol (Levatol)
69
β1-selective Antagonist w/ ISA drug?
Acebutolol (Sectral)
70
β-Antagonists ISA drugs used to tx?
HTN
Angina
Glaucoma (Carteolol)
71
β-Antagonists ISA drug benefits?
less - effects on plasma lipids?
| (P) less bronchocon, bradycard
72
Labetalol affects what receptors?
⍺1, β1, β2
| blocker
73
Labetalol effects on ⍺1?
β1?
↓ peripheral vascular resistance
prevents reflex ↑ HR (tachycardia)
74
Labetalol use to tx?
HTN
| HTN emergencies
75
Carvedilol affects what receptors?
⍺1, β
| blocker
76
Carvedilol effects on ⍺1?
β?
↓ peripheral vascular resistance
prevents reflex ↑ HR (tachycardia)
77
Carvedilol used to tx?
HTN
CHF
post MI
78
Guanethidine (Ismelin) affects neurotransmitters how?
Method of action?
inhibits release of NE from terminal
replaces NE stores in vesicles
79
Guanethidine effects inhibited by what type of drugs?
uptake inhibitors:
| TSA, cocaine
80
Guanethidine s/e?
complete loss of sympathetic activity:
severe hypoTN
↓ blood to brain/heart
81
Reserpine affects neurotran how?
Results in?
interefers w/ uptake and storage
depletion of NE, DA, serotonin in periphery/brain
82
Reserpine s/e?
sedation, depression, parkinson's sxs
83
Metyrosine (Demser) affects neurotrans how?
Results in?
blocks synthesis of DA (blocks tyrosine hydroxylase enz)
↓ NE, Epi
84
Metyrosine used for?
pre-surg and inoperable pheochromocytoma
