Adrenergic Drugs Flashcards
1
Q
Adrenergic drugs are useful in treating?
A
a LOT
- hypertension
- angina
- HF
- Asthma
etc. ..
2
Q
Response to adrenergic drugs depends on…
A
proportion of a and b receptors in a tissue
3
Q
NE and E difference in regards to receptors
A
NE little effect on B2 so cannot cause bronchodilation
E is a great bronchodilator
4
Q
What receptors do skin blood vessels have?
A
a1
= vasoconstriction
5
Q
What receptors do smooth muscle of blood vessels in skeletal muscles?
A
a1 AND b2
so a1 = vasoconstriction and b2 = vasodilation
6
Q
Epinephrine at low dose causes…
A
Vasodilation
7
Q
Epinephrine at high dose causes…
A
Vasoconstriction
bc a1 predominates
8
Q
Adrenergic agonists:
A
- Direct
- Endogenous catecholamines
- B agonists
- A agonists - Indirect
- Releasing agents
- Uptake inhibitors - Mixed
9
Q
Endogenous catecholamines
A
- NE
- E
- Dopamine
10
Q
Epinephrine effects on organs
A
- agonist at both a and b receptors
B1 effect: - increase in HR
- increase in renin
A1 effect:
- vasoconstriction
B2 effect:
- bronchodilation
- glycogenolysis
- lipolysis (b1 and b2)
- dilation of skeletal muscle
11
Q
E in IV large dose increases?
A
BP due to B1 and A1 effects
12
Q
E in IV low dose?
A
no increase in mean BP
B2 dominates = diastolic pressure falls
B1= increase systolic pressure and HR
13
Q
Epinephrine uses
A
- Anaphylactic shock
- Acute asthmatic attacks
- Cardiac arrest
- Local anesthetics
14
Q
Norepinephrine
A
agonist at a1, a2, b1 receptors
- increased HR (b1)
- increased vasoconstriction (a1)
increase in BP
baroreceptor reflex = bradycardia
15
Q
Norepinephrine uses
A
- treat shock
16
Q
Norepinephrine interesting fact:
A
If atropine is given before NE then NE will cause tachycardia
17
Q
Dopamine
A
D1 > B1 > a1 receptors
18
Q
Low rates of dopamine
A
- vasodilation
- increase in GFR
- increase in renal blood flow
- increase Na excretion
19
Q
Moderate rates of dopamine
A
- B1 activation = increase CO = increase in SBP
- increase in MAP
- release of NE
20
Q
High rates of dopamine
A
- a1 activation = vasoconstriction = increase BP
- PVR increase
21
Q
Dopamine uses:
A
CHF
moderate to high rates for shock
22
Q
B agonists:
A
- Non selective
- Isoproterenol - B1 selective
- Dobutamine - B2 selective
- Albuterol
- Salmeterol
- Formoterol - B3 selective
- Mirabegron
23
Q
Isoproterenol
A
B1 and B2
- increases HR
- dilation of skeletal muscle
- DBP falls
- MAP falls
- bronchodilation
24
Q
Isoproterenol use:
A
emergency to stimulate HR in pt with bradycardia
25
Dobutamine
- potent inotrope with mild chronotropic effects
- mild effects
- increase O2 consumption = dobutamine stress echocardiogram
26
Dobutamine use:
- acute HF
| - cardiogenic shock
27
B2 agonist used mainly for?
bronchodilation (B2)
| asthma
28
Short acting vs Long acting:
SA:
- Albuterol
LA:
- Salmeterol
- Formoterol
29
B2 AE:
- tremor, restlessness, anxiety, tachycardia
30
Mirabegron
B3 in bladder = detrusor muscle relaxation and increased bladder capacity
used for overactive bladder
AE: increased BP, UTI, headache
CYP2D6 inhibitor
31
A agonists:
1. A1 selective
- phenylephrine
2. A2 selective
- clonidine
- methyldopa
- brimonidine
32
Phenylephrine
vasoconstriction A1
used:
- nasal decongestant
- treat hypotension
- mydriatic
33
Clonidine
- partial a2
- hypertensive
AE: lethargy, sedation
34
Methyldopa
- decrease BP
- hypertension during pregnancy
AE: sedation, impaired mental concentration
35
Brimonidine
- lower pressure in glaucoma
36
Indirect acting agonists:
1. releasing agents
- amphetamine
- methylphenydate
- tyramine
2. uptake inhibitors
- Cocaine
- Atomoxetine
- Modafinil
37
Amphetamine mechanism
- reverse action of monoamine transporters = inhibit VMAT = increase in monoamines
38
Amphetamine action
- increase BP
AE: nervousness, insomnia, hypertension, anorexia
USED:
- ADHD
- Narcolepsy
39
Methylphenidate
ADHD in kids
40
Tyramine
found in fermented food
| usually oxidized by MAO
41
Cocaine
- blocks DAT
- high conc block SERT and NET
- blocks voltage gated NA channels
effects: tachycardia, hypertension, seizures
42
Atomoxetine
- inhibit NET
| - ADHD
43
Modafinil
MOA not known
- psychostimulant
- blocks NE and Dopamine transporters = increase in NE, dopamine, serotonin, glutamate
- decrease GABA
- narcolepsy
44
Mixed agents:
1. Ephedrine
2. Pseudoephedrine
- release of NE
- activate adrenergic receptors
45
Ephedrine
pressor agent used in spinal anesthesia
- used in myasthenia gravis
46
Pseudoephedrine
- decongestant
47
Adrenergic Antagonists:
1. A antagonists
- nonselective
- a1
2. B antagonists
- non selective
- b1
3. A1 and B antagonists
4. Partial agonists
5. Presynaptic drugs
48
Non selective A blockers:
- phenoxybenzamine
| - phentolamine
49
phenoxybenzamine
- irreversible
| - pheochromocytoma
50
phentolamine
- reversible block of a1 and a2
used in:
- diagnosis of pheochromocytoma, hypertension
- hypertensive crisis due to stimulant drug overdose
51
ALL a blockers do what?
reverse epinephrine effects --> decrease in BP when given epinephrine and a blocker
52
A1 selective blockers:
"sins"
- prazosin (prototype)
- terazosin
- doxazosin
- tamsulosin
used in hypertension and BPH
53
A1 selective blockers CV effects
- low BP
| - first dose causes big response = fainting so first dose must be 1/3 or 1/4 normal dose
54
Non selective B blockers:
- Propranolol
- Nadolol
- Timolol
55
B blocker effects:
CV: slow HR and decrease contractility
Resp: contraindicated in pt with asthma
Metabolic: decrease glycogenolysis and glucagon secretion
56
B1 selective antagonists:
Atenolol
Metoprolol
Esmolol
57
Atenolol & Metoprolol
- hypersensitive pt with bad pulmonary function
58
Esmolol
rapid control of ventricular rate in pt with atrial fibrillation or atrial flutter
59
a1 and b blocker:
Labetalol
| Carvedilol
60
Labetalol
hypertension
61
Carvedilol
hypertension and CHF
62
Partial B agonist:
Pindolol
63
Pindolol
diminished cardiac reserve or bradycardia
64
B blocker use:
- hypertension - decrease CO
- glaucoma- esp timolol
- migrane
- hyperthyroidism
- angina pectoris- chronic management*
- atrial fibrillation
- MI
- bleeding from esophageal varices in cirrhosis
- performance anxiety
- essential tremor
65
B blockers AE:
- bronchoconstriction: especially non selective, B1 is better
- hypoglycaemia: espeically non selective, B1 better
- lipid metabolism: both non selective and B1 increase TG and reduce HDL--> unaffected by labetalol and pindolol
- sedation, fatigue, dizziness
66
Should B blockers be withdrawn fast or slow and why?
slowly to avoid tachycardia, hypertension, ischemia
67
Presynaptic drugs:
1. inhibit NE synthesis
- a-methyltyrosine
2. Inhibit NE storage
- Reserpine
- tetrabenazine
68
a-methyltyrosine
inhibitor of tyrosine hydroxylase
| - used to manage pheochromocytoma
69
Reserpine
blocks VMAT
cannot store NE and D
MAO degrades NE in cytoplasm --> decrease BP and cardiac rate
- past for hypertension
70
tetrabenazine
inhibits VMAT
- depletion of catecholamines
- treats chorea in Huntington's
71
The eye has 2 muscles:
1. Radial A1
| 2. Sphincter M3
72
M agonist effect in eye
Contraction of sphincter M3= miosis
73
Anti-M in eye:
relaxation of sphincter M3 = mydriasis
74
a-adrenergic agonist in eye:
contraction of pupillary dilator in eye (radial muscle a1) = mydriasis
reduces aqueous humor production --> decrease pressure --> helps glaucoma
75
b antagonists in eye
secretion of aqueous humour
blocking B2 --> reduces secretion --> helps glaucoma
76
Prostaglandins in eye
found in ciliary body, muscle, wtc
increases uveoscleral outflow --> reduces pressure --> helps glaucoma
77
Carbonic anhydrase inhibitors in eye
inhibit CA in ciliary body of epithelium--> reduces aqueous humor --> reduce pressure --> helps glaucoma
