Adrenergic lecture

Question 1

SNS

Answer 1

Organ systems, blood pressure
Hormone vs. neurotransmitter
Adrenal medulla

Question 2

NT Termination
Acetylcholine
(2)

Answer 2

ACh-esterase
150ms

Question 3

NT Termination
Norepinephrine
(3)

Answer 3

Reuptake
Monoamine oxidase
Catechol-O-
Methyltransferase

Question 4

sympathetic agonists
Direct
(3)

Answer 4

Route
Affinity
Expression of receptor subtypes

Question 5

sympathetic agonists
Indirect
(2)

Answer 5

Catecholamine displacement
Amphetamines

Decreased NE clearance
Reuptake inhibition

Question 6

adrenergic receptors
(4)

Answer 6

α1 α2
β1 β2
Dopamine
Sympathomimetic vs sympatholytic

Question 7

adrenergic receptors
Can be downregulated / desensitized
(3)

Answer 7

Congestive Heart Failure (CHF)
Acidosis
Hypoxia

Question 8

α1
(6)

Answer 8

Peripheral vascular beds
Excitatory

Vasoconstriction
Blood pressure increased
Mydriasis
Urinary sphincter constriction

Question 9

α2
(6)

Answer 9

Inhibitory

In the vasculature
Inhibition of NE and ACh
Decreased sympathetic tone
Decreased BP
Sedation

Question 10

β1
(3)

Answer 10

Excitatory

Cardiac excitation
Increased rate, contractility,
conduction

Question 11

β2
(5)

Answer 11

Inhibitory

Bronchodilation
Smooth muscle relaxation
Skeletal muscle vasodilation
Decreased vascular resistance

Question 12

DA
Resistance vessel vasodilation
(4)

Answer 12

Renal
Splanchnic
Coronary
Cerebral

Question 13

Primary catecholamines

Answer 13

Dopamine (DA) and
norepinephrine (NE)

Question 14

DA –
NE –
Epinephrine –

Answer 14

Brain and kidney
Sympathetic nerve endings
Adrenal medulla

Question 15

norepinephrine

Answer 15

a1, b1, b2
Endogenous
Primary neurotransmitter at sympathetic nerve endings
Maintenance of sympathetic tone
BP
No cardiac output changes
Minimal chronotropic changes
Increased coronary blood flow
Caution with prolonged infusions

Question 16

epi
@ higher doses
@ lower doses
@ lower doses

Answer 16

α1
β1
β2

Question 17

epi

Answer 17

Endogenous
Only released by adrenal medulla
Stress preparation
coronary blood flow
Caution prolonged infusions

Question 18

DA
α1
β1
β2

Answer 18

Endogenous
NE precursor
Dose-specific effects
Low dose (0.5 – 3 mcg/kg/min)
Intermediate (3 – 10 mcg/kg/min)
High (10 – 20 mcg/kg/min)

Question 19

dobutamine
β1
β2
α1

Answer 19

Synthetic
Augments myocardial contractility
Dose-dependent increase in stroke volume (SV) and cardiac output (CO)
Alpha agonist AND antagonist
Beta-mediated vasodilation (low dose)
High dose increases myocardial O2 consumption

Question 20

phenylephrine
α1

Answer 20

Synthetic
All alpha, no beta
Not a catechol derivative, not
metabolized by COMT
Can lead to baroreceptor-mediated
decrease in HR
Push dose pressor

Question 21

milrinone
β1“like effect”
β2“like effect”

Answer 21

Phosphodiesterase-3 inhibitor
Inhibits breakdown of cAMP
Positive inotropy
Potent vasodilator
Increased diastolic relaxation
Reduced preload and afterload
Good in the setting of receptor
downregulation

Question 22

vasopressin
α1“like effect”

Answer 22

AKA: antidiuretic hormone
Stored in posterior pituitary
Released when plasma osmolality increases or BP drops
V1 and V2 receptor agonist
Neutral to negative impact on CO
Dose dependent SVR and vagal tone increase
Not affected by pH

Question 23

Alpha-2 selective agonists
ex (4)

Answer 23

Clonidine
Dexmedetomidine
Guanfacine
Methyldopa

Question 24

Alpha-2 selective agonists
(3)

Answer 24

Drop BP by reducing
sympathetic tone
Effective antihypertensive
Class effect = sedation Clonidine

Question 25

indirect acting sympathomimetics mechanism (2)

Answer 25

Displacers Reuptake inhibition

Question 26

amphetamine like agents Amphetamine (3)

Answer 26

Rapid CNS uptake Stimulant Effects mediated by NE and DA

Question 27

Methylphenidate (Ritalin) (4)

Answer 27

Amphetamine variant Similar effect and abuse potential Use: ADD-spectrum Caution - UDS

Question 28

Modafinil (Provigil) (5)

Answer 28

Psychostimulant Totally different from amphetamine NE, DA reuptake inhibition NE, DA, 5-HT3, glutamate increase; GABA decrease Use: narcolepsy

Question 29

Straterra (3)

Answer 29

Selective NE reuptake inhibition No CV effects Clonidine-like effect Use: ADD

Question 30

Cocaine (5)

Answer 30

Local anesthetic, peripheral sympathomimetic Reuptake inhibition, especially dopamine Excited delirium Avoid concurrent beta- blockade Use: epistaxis

Question 31

Beta-2 agonism

Answer 31

Key to management of acute asthma Common “allergy” in dentistry7.9% Triggered by allergens, stress, food, drugs Angioedema = similar but different

Question 32

acute management ex (3)

Answer 32

Albuterol Levalbuterol Terbutaline

Question 33

acute management (2)

Answer 33

Short term control Short acting beta agonists (SABA)

Question 34

Long term management ex (2)

Answer 34

Formoterol Salmeterol

Question 35

Long term management (4)

Answer 35

Longer term control Long acting beta agonists (LABA) Blocks receptors 12-18h NOT FOR ACUTE ATTACKS

Question 36

NOT FOR ACUTE ATTACKS Have to be used with steroids Advair = Symbicort = Dulera –

Answer 36

salmeterol + fluticasone formoterol + budesonide formoterol + mometasone

Question 37

dental management of asthma patients (3)

Answer 37

Minimize likelihood of exacerbation Talk to your patient to learn their management strategies Instruct pt. to bring albuterol inhaler to all appointments Decrease stressors

Question 38

dental management of asthma patients Drug considerations (4)

Answer 38

No ASA or NSAIDS Avoid histaminic drugs Avoid antihistamines Avoid cholinergics

Question 39

dental management of asthma patients In an emergency (3)

Answer 39

Supplemental O2 Consider epinephrine 0.3 mg IM (or use EpiPen)

Question 40

alpha receptor antagonists Two types Reversible (2) Irreversible (2)

Answer 40

Concentration dependent Duration dependent on t1/2 Body has to generate new receptors Drug effect can persist even after drug is cleared

Question 41

alpha receptor antagonists Pharmacologic Effects Cardiovascular (2) Other (2)

Answer 41

α1 blockade blocks vasoconstriction Orthostatic hypotension Miosis, nasal stuffiness Decreased resistance to urinary flow

Question 42

phentolamine (3)

Answer 42

Blocks α1 and α2 Decreased PVR and cardiac stimulation Can lead to CV adverse reactions

Question 43

PrazosinTerazosinDoxazosin

Answer 43

Selective α1 Arterial and venous vascular smooth muscle relaxation and prostate relaxation 50% bioavailabilityFirst pass effect T1/2

Question 44

T1/2 Prazosin: Terazosin: Doxazosin:

Answer 44

3h 9h 22h

Question 45

Tamsulosin

Answer 45

Competitive α1 blocker High bioavailability More specific to prostate Less orthostatic hypotension

Question 46

Beta Blockers

Answer 46

Antagonize effects of catecholamines and beta agonists Differ in affinity for β1 and β2 β1 specificity decreases as dose increases End in -lol (-olol, -ilol, -alol)

Question 47

Receptor affinities Labetalol, carvedilol Metoprolol, betaxolol, acebutolol, esmolol, atenolol, nebivolol Propranolol, carteolol, penbutolol, pindolol, timolol

Answer 47

β1= β2 > α1 > α2 β1>>> β2 β1= β2

Question 48

Beta-1 specific

Answer 48

Betaxolol Esmolol Acebutolol Metoprolol Atenolol Nebivolol

Question 49

Esmolol (5)

Answer 49

Beta-1 selective Short t1/2 Quick onset Requires central line for administration Great for tight BP control

Question 50

Labetalol

Answer 50

Beta and alpha blockade 3:1 oral 7:1 IV Dose dependent duration of action up to 20 hours

Question 51

--- specific drugs safer for asthmatic patients Caution with

Answer 51

β1 non-specific β- blockers and epi