Adrenergic Drugs Flashcards
1
Q
What receptors are activated for epinephrine?
A
alpha-1, alpha-2
beta 1,2,3
B1 = B2 = B3 > a2
2
Q
what receptors are activated for NE?
A
alpha1, alpha2, beta 1
Alpha»_space;> Beta
3
Q
What receptor is activated for Phenylephrine?
A
alpha-1
4
Q
What receptors are activated for Clonidine and Apraclonidine?
A
alpha-2
5
Q
What receptors are activated for Isopreternol?
A
Beta 1,2,3
6
Q
What receptor is activated in Dobutamine?
A
Beta 1 selective agonist
7
Q
What receptor is activated for Albuterol/Salmeterol
A
Beta 2 selective agonist
8
Q
What receptors are activated for Dopamine?
A
D1, D2
9
Q
Ephedrine (dopamine)
A
direct and indirect acting
10
Q
Tyramine, Methyldopa, Cocaine, Amphetamine
A
Indirect-acting (mainly, but is mixed)
11
Q
What is the MOA Indirect- acting adrenergic drugs?
A
1) stimulation of release of catecholamines from adrenergic nerve endings
a. facilitated exchange diffusion
b. false-transmitter concept
2) inhibition of re-uptake of catecholamines already released (some indirect acting adrenergic drugs inhibit the re-uptake of NE by blocking the amine transport system)
12
Q
Role of Reflex Homeostatic adjustments– Epinephrine:
Systolic BP
Diastolic BP
A
Increases Systolic BP
Decreases Diastolic BP
13
Q
Role of Reflex Homeostatic adjustments– Epinephrine:
Direct action on cardiac rate
A
Increased
14
Q
Role of Reflex Homeostatic adjustments– Epinephrine:
Reflex action on cardiac rate
A
Decresaed
15
Q
Role of Reflex Homeostatic adjustments– Epinephrine:
Final effect on cardiac rate
A
Increased
16
Q
Role of Reflex Homeostatic adjustments– NE
Systolic BP
Diastolic BP
A
Increases both
17
Q
Role of Reflex Homeostatic adjustments– NE
Direct action on cardiac rate
A
Increases
18
Q
Role of Reflex Homeostatic adjustments– NE
Reflex action on cardiac rate
A
DECREASES
19
Q
Role of Reflex Homeostatic adjustments– NE
Final effect on cardiac rate
A
decreases
20
Q
Role of Reflex Homeostatic adjustments– ISO
Systolic BP
Diastolic BP
A
Increases Systolic
Decreases Diastolic
21
Q
Role of Reflex Homeostatic adjustments– ISO
Direct action on cardiac rate
A
increases
22
Q
Role of Reflex Homeostatic adjustments– ISO
Reflex action on cardiac rate
A
increases
23
Q
Role of Reflex Homeostatic adjustments– ISO
Final effect on cardiac rate
A
INCREASES
24
Q
Pharmacodynamics EPI (Heart)
A
cardiac = B1 (mostly) some B2
Increased HR
Increased conduction
Increased contractility
DECREASED cardiac efficiency
25
Pharmacodynamics EPI (Vessels):
Vasoconstriction predominates where?
Vasodilation predominates where?
Vasoconstriction: Cutaneous, GI, Renal Vessels (alpha-1)
Vasodilation: Skeletal muscle & Liver (Beta-2)
26
Pharmacodynamics EPI (Blood Pressure):
Low doses EPI cause increase or increase in bp?
Decrease (Vasodilation B2)
27
Pharmacodynamics EPI (Blood Pressure):
Intermediate doses EPI cause increase or increase in bp?
Systolic BP increases (due to rise in CO)
Diastolic BP decreases (B2 receptor mediated vasodilation usually predominates)
Mean BP is usually slightly elevated
28
Pharmacodynamics EPI (Blood Pressure):
High doses EPI cause increase or increase in bp?
both systolic and diastolic BP INCREASE (B1)
29
Pharmacodynamics EPI (Respiratory Sys):
Effects on smooth muscle, mucociliary clearance?
bronchial smooth muscle relaxation
INCREASED mucociliary clearance
30
Pharmacodynamics EPI (GI)
effects on smooth muscle, peristalsis, sphincters?
Relaxation of smooth muscle (a2 on cholinergic reduces ACh release, activaiton of b2 receptors directly relaxes smooth muscle)
decreased GI peristalsis
Contraction of sphincters (a1)
31
Pharmacodynamics EPI (GU)
contraction of trigone and internal sphincter, relaxation of pregnant uterus
32
Pharmacodynamics EPI (CNS):
lacks direct central effects (bc epi doesnt enter CNS)
33
Pharmacodynamics EPI (Eye):
does EPI cause mydriasis or ____.
Does it decrease or increase intraocular pressure?
contraction of radial muscle of iris --> mydriasis
DECREASED intraocular pressure
34
Pharmacodynamics EPI (skeletal muscle)
causes what in skeletal muscle?
tremor (B2 accelerates sequestration of cystolic Ca and enhances discharge of muscle spindles)
increased K+ uptake into cell (B2 activation)
35
Pharmacodynamics EPI (metabolic effects):
epinephrine causes hyper or hypoglycemia?
hyperglycemia:
1) inhibition of insulin secretion
2) stimulation of glycogenolysis and gluconeogenesis
3) stimulation of glucagon secretion
+
increased lipolysis (B3)
36
What is the Route of Administration for Epinephrine?
Parenteral ONLY! (0% oral bioavailability)
37
What is the half life of epinephrine?
2 minutes
38
What are the adverse effects of EPI in the CNS?
restlessness, throbbing HA, dizziness, tremors, weakness, dyspnsea
cerebral hemorrhage (rare- from increased BP)
39
What are the adverse effects of EPI in CVS?
HPT, pallor
anginal pain (in patients with CHD), sinus tachy, ventricular arrhythmias
pulmonary edema (rare)
40
Therapeutic uses of Epinephrine
serious acute hypersensitivty rxn (anaphylaxis, angioedema)
Cardiac arrest (a1 receptor activation)
prevention of surgical bleeding (given topically for superficial wounds)
to retard absorption of local anesthetics
41
in cardiac arrest what receptor does epi activate to increase venous return?
alpha 1
42
What is the final effect of NE on the heart?
decrease in HR
43
What is NE action on the Vessels?
Vasoconstriction predominates in all vascular beds (except coronary and pulmonary where autoregulatory actions override direct vasoconstrition effect of NE)
44
Is BP increased or decreased when EPI is given?
increased (but pulse pressure doesn't change)
45
therapeutic uses of NE?
hypotension and vasodilatory shock (due to spinal trauma, spinal anesthesia, sepsis)
with local anesthetics (to retard their absorption)
46
What is the MOA and pharmacological effect of dopamine at low doses?
activation of D1 receptors
vasodilation in kidney, mesenteric and coronary beds
inhibition of Na+ reabsorption in PCT
(overall --> increased diuresis!)
47
What is the MOA and pharmacological effect of dopamine at intermediate doses?
activation of B1 receptors + release of NE from nerve terminals
increased stroke volume and HR
48
What is the MOA and pharmacological effect of dopamine at high doses?
activation of a1 and d2
increased systemic vascular resistance, nausea, and vomiting
49
what is the route of administration of dopamine?
IV infusion only
50
half life of dopamine
2 mins
51
therapeutic uses of dopamine
cardiogenic, neurogenic and septic shock
52
mechanism of action of a1 receptor agonist
Gq --> PLC
1) IP3 --> inc. Ca2+ --> Increased contraction of vascular smooth muscle
2) DAG --> Protein kinase C --> Inc. Ca+ --> increased contraction of vascular smooth muscle
53
effects on cardiovascular system of alpha1 agonist
increase in blood pressure associated with bradycardia because of activation of baroreceptor reflex
54
which class of drugs can cause rebound congestion (when used as nasal decongestant) as an adverse effect?
phenylephrine (a1 agonist)
55
therapeutic uses of alpha 1 agonists
aka. phenylephrine
postural hypotension
nasal or ocular decongestant
mydriatics
local vasoconstrictor (i.e in epistaxis)
to prolong action of local anesthetics
56
drugs that act on a2 and imidazoline receptors
clonidine
| apraclonidine
57
drugs that act on a2 receptors
Guanfacine
| Tizanidine
58
MOA of clonidine
1) activation of PREsynaptic a2 receptors located in nucleus of tractor solitarius in rostral ventrolateral medulla
2) activation of non-adrenergic binding sites-- imidazoline receptors
Overall-- decreased firing of reticulospinal tract which decreases central adrenergic tone (main antihypertensive MOA of clonidine)
59
effects of a2 selective agonists on CVS
i. e. clonidine
1) low/intermediate-- hypotension
2) high-- Hypertension
60
effects of a2 agonists on CNS
i.e. clonidine
craving-reducing effects in addicts
sedative effects
analgesic effects
61
half life clonidine
12 hours
62
therapeutic uses of a2 agonists
i.e. clonidine
1) HTN (second choice drugs)
2) open angle glaucoma
3) withdrawal from tobacco, alc or opiods
4) preanesthetic medication to induce preoperative sedation and reduce requirement for anesthetic
5) severe pain
6) diabetic neuropathy
7) neuropsychiatric disorders (Tourettes, ADHD, autism)
63
effects of B-agonists on the Heart
i.e. Isoproterenol
Increased HR (tachycardia)
64
effects of B-agonists on vessels
i.e. isoproterenol
b2 mediated vasodilation predominates in all vascular beds
65
effects of B-agonists on BP
i.e. Isoproterenol
systolic BP remains unchanged or increases
Diastolic BP decreases sharply
Mean BP usually falls
66
administration of isoproterenol
IV infusion only
67
therapeutic uses of isoproterenol
emergency situations where heart contractility is low and HR is slow yet peripehral resitance is high (i.e. Cardiac surgery)
Torsade de Pointes (polymorphic Vtach)
68
MOA of increased cardiac contractility of B1 receptor agonist:
(i.e. Isoproterenol)
Gs --> Adenylyl cyclase --> inc. cAMP --> Protein Kinase A:
1) increased phosphorylation of troponin C
2) inc. opening of voltage gated Ca2+ channels
3) inc. Ca2+ reuptake by SR
69
MOA of increased cardiac conduction by B1 receptor agonist
Gs --> adenylyl cyclase --> inc. cAMP --> protein kinase A --> opening Na+ channels --> depolarization of cell membranes of SA node, AV node and Ventricular conduction system
70
pharmacological effects of dobutamine on the heart
b1 agonist
increase contractility and conduction
71
therapeutic uses of dobutamine?
b1 agonist
Iv infusion to patients with cardiac failure or cardiogenic shock
72
effects of albuterol/salmeterol on respiratory system
b2 agonist
bronchodilation, enchanced mucociliary clearance, suppression of release of inflammatory mediators (leukotrienes, histamine), reduction of microvascular permeability
73
administration of albuterol/salmeterol
inhalation (main route), po, sc
74
MOA of smooth muscle relaxation by B2 receptor agonists
i.e. albuterol
Gs --> adenylyl cyclase --> inc. cAMP --> protein kinase A:
1) Inc. Ca2+ efflux --> decreased smooth muscle contraction
2) inc. inactivation of myosin-light-chain kinase --> dec. phosphorylation of myosin light chains --> decreased smooth muscle contraction
75
adverse effect of B2 receptor agonist on CNS
tremor, muscle cramps
76
Therapeutic uses of albuterol/salmeterol
b2 agonist
1) asthma
2) COPD
3) Hyperkalemia
4) premature labor
77
Tyramine
direct or indirect adrenergic drug?
Indirect acting adrenergic drug
78
MOA of tyramine
false transmitter taken up by adrenergic neurons where it is transformed into octopamine
79
Pharmakokinetics of tyramine
normal byproduct of tyrosine metabolism in body
inactive if ingested because of a very large fisrt-pass effect
80
clinical uses of tyramine
localize lesion of sympathetic nerves
81
MOA of Methyldopa
(indirect adrenergic drug)
false NT which is taken up by adrenergic neurons where it is transformed into methylnorepinephrine (a2 receptor agonist)
activation of central a2 receptors by methylnorepinephrine reduces central adrenergic tone
82
MOA of amphetamines
indirect acting adrenergic drug
stimulation of release of monoamines (NE, dopamine, serotonin)-- peripherally and centrally
83
MOA of cocaine
indirect-acting adrenergic drug
blockade of reuptake of monoamines (NE, dopamine, and serotonin)
84
Ephederine MOA
activation of a1, a2, b1 and b2 receptors
enhanced release of NE from adrenergic neurons
it is an over the counter ingredient in decongestants
85
what drugs would you give for cardiogenic shock?
dobutamine, dopamine
86
what drugs would you give for vasodilatory shock (i.e. neurogenic, septic?)
NE, Phenylephrine, dopamine
87
What drugs would you give for anaphylactic shock, CPR?
epinephrine
88
what drug would you give for torsade de pointes?
isoproterenol
89
what drug would you give for HTN?
clonidine or methyldopa
90
what drugs would you give for local anesthesia (to cause local vasoconstriction?)
epinephrine, NE
91
what drugs would you give for asthma, copd?
b2 selective agonists or epinephrine
92
what drugs woudl you give for anaphylaxis or angiodema?
epinephrine
93
what drug would you give for open anlge glaucoma?
apraclonidine
94
what drug woudl you give for narcolepsy, ADHD, weight reduction?
amphetamines and congeners
95
what drug woudl you give for withrdawal from tobacco, alcohol or opiods? or Tourettes syndrome, ADD, etc.
clonidine
