Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Foundations 2 > Adrenergic Agents > Flashcards

Adrenergic Agents Flashcards

1
Q

general principles for characterizing receptors and subtypes

A

block agonist effects by specific competitive agonists

potency (selectivity) sequences of agonists

molecular biology, cloning receptors and demonstrating different structural subtypes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

EPI reversal

A

high doses of EPI with ergotoxin (alpha1 blocker) decreases blood pressure instead of increasing it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

effects of alpha1 receptors

A

contraction of iris, bronchioles, vascular smooth muscle, splenic capsule, uterine smooth muscle, male sexual organs, pilomotor muscle, urinary bladder, gastrointestinal sphincters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

effects of beta2 receptors

A

relaxation of bronchioles, vascular smooth muscle, splenic capsule, uterine smooth muscle, urinary bladder, and intestinal smooth muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

effects of beta1 receptors

A

increase cardiac sinus rate, contractile force, and conduction

renin release in kidney

increases aqueous humor secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

effects of alpha2 receptors

A

relaxation of intestinal smooth muscle

decrease in cardiac sinus rate

accumulation of fat

decrease in insulin secretion

decrease in aqueous humor secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

contractile and secretory signal transduction motif

A

for alpha1 agonists

phospholipase C activation, fast enzymes

G protein stimulation, rapid increase in cytoplasmic Ca concentration

mediates CRAC channels aka store-operated calcium channels (SOCs) to open

amplifies contractile response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

protein kinase A/cyclic AMP signal transduction motif

A

for beta agonists

slower, metabolic processes used by beta receptors

involves G protein-linked synthesis of cAMP and PKA phosphorylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

alpha2 receptor mechanism

A

G-protein mechanism that opens potassium channels and reduces excitability of cells

blocks calcium channels

inhibits adenylyl cyclase

direct effect on neurotransmitter release through the secretary apparatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

three prototype chatecholamines and their structure-activity releationships

A

norepinephrine - good stimulant of alpha and beta1, but no beta2

epinephrine - good stimulant of alpha, beta1, and beta2

isoproterenol - good stimulant of beta1 and beta2, but no alphas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

non-cardiovascular effects of the prototypes

A

mydrasis - alpha potency

bronchiolar relaxation - beta2 potency

intestinal relaxation and glycogenolysis - produced by all types, EPI is the best

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

direct cardiovascular effects of the prototypes

A

heart rate increased by beta1 receptors, increased rate of diastolic depolarization by stimiulating pacemaker current If and Ca currents

force is augmented by increasing calcium entry from outside the cell and SR

most vascular beds have both alpha and beta2 receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

three things to consider when looking at vascular bed effect of a catecholamine

A

selectivity of the drug

ratio of alpha to beta2 receptors

concentration of the drug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

describe a cardiac action potential

A

sodium current

potassium opens at peak

L-type calcium channel maintains depolarization

delayed rectifiers restore the polarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

effect of norepinephrine on heartrate, blood pressure, and TPR

A

decrease TPR

increase in blood pressure

decreased heart rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

effect of epinephrine on heartrate, blood pressure, and TPR

A

decreas in TPR

small increase in blood pressure

increased pulse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

effect of isoproterenol on heartrate, blood pressure, and TPR

A

decreased TPR

small decrease in pressure

increased heartrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What happens when a high dose of EPI is administered to the heart?

A

increase and rate and force, leading to a great increase in systolic blood pressure

subsequent to this there is an increased diastolic pressure due to alpha vasoconstriction by the high EPI concentration

result is a rapid rise in mean blood pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

therapeutic uses of prototypes

A

bronchodilator = beta 2

mydriatic = alpha

increased cardiac contractile force = beta1

vaso constrictor = alpha

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

contraindications of catecholamines

A

pressor effects - high bp, hyperthyroid problems

arrhytmias - hyperthyroid patients have more beta receptors

diabetes

narrow angle glaucoma

prostate enlargement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

absorption, fate, and excretion of clinical prototypes

A

EPI - oral absorption satisfactory, but metabolized by MAO in gut and liver, little effect

NE - orally ineffective, poor absoprtion from subcutaneous injection site, usually given by IV infusion, quickly inactivated in the body

iSO - poor substrate for MAO due to N-isopropyl group so longer acting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

selective alpha1 receptor agonists

A

phenylephrine

imidazoline derivatives

midodrine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

physiologcially relevant alpha2 sites involved in the control of blood pressure

A

tonic firing of sympathetic nerves contribute to cardiac output via beta1 receptors and to the tonic constirction of blood vessels via alpha1 receptors

the activation of alpha2 receptors in the hypothalamus or the medulla inhibits this tonic sympathetic firing and relieves the tonic constriction of blood vessels, thus reducing blood pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

alpha2 receptor agonists

A

clonidine

guanfacine

guanabenz

alpha-methyl dopa

apraclonidine

brimonidine

25
Q

clonidine suppression test

A

used to distinguish essential hypertension from pheochromocytoma

has no effect in pheo because there is such a high amount of NE present

26
Q

beta1 receptor agonist

A

dobutamine

27
Q

“selective” beta2 receptor agonists

A

all are resistant to COMT action and are metabolized by sulfate conjucation

albuterol

terbutaline

ritodrine

salmeterol

formoterol

28
Q

indirect sympathomimetic agents

A

tyramine and amphetamines

29
Q

tachyphylaxis

A

depletion of NE with indirect sympathomimetic amines such as tyramine

30
Q

effect of Uptake 1 inhibitor on tyramine

A

drastic increase in bp

31
Q

effect of a MAO inhibitor tyramine

A

hypertensive crisis

32
Q

mixed acting sympathomimetic amines

A

epedrine derivatives such as speudoephedrine

33
Q

clinical uses of sympathomimetic amines in the periphery

A

treatment of spasm of bronchiolar smooth muscle associated with asthma

nasal decongestants

cardiac effects

premature labor and other OB uses

34
Q

treatment of asthma

A

EPI inhaler for quick action

isoproterenol also available

over-the-counter prophylaxis - primatene tablets with ephedrine

non-selective agents that produce tachycardia such as albuterol, salmeterol, and formoterol

35
Q

mechanism of nasal congestion

A

unusual vessles with erectile properties that fill the sinusoids

vessels ahve venous fluid reservoir, so that when they dilate, then more fluid is in the mucosa, and more mucus is secreted and mroe nasal congestion occurs

36
Q

nasal decongestants

A

phenylephrine for short term relief

imidazoline derivatives

problem with long-term use is the release of metabolites locally so that the rebound congestion is worse

blood vessels also constrict because of extrajunctional alpha2B effects - reactive hyperemia

37
Q

cardiac arrest treatments

A

EPI has been found to be useful here for a great number of years

the beta1 stimulatory effect is obvious but the main benefit may be secondary to vasoconstriction

38
Q

cardiogenic shock treatments

A

tremendous fall in cardiac output

fall in areterial systolic pressure

reflex tachcardia

reflex venous constriction

oliguria

treatment with dobutamine to increase CO with minimal increas in heart rate

treatment with dopamine to increase cardiac output with an additional vasodilator effect

39
Q

treatment for severe hypotension in the ICU

A

levophed because it is norepinephrine, only clinical use

40
Q

premature labor and other OB treatments

A

terbutaline - beta2 agonist, so relaxes uterus

41
Q

adrenergic blocking agetns

A

drugs that block adrenergic activity

traditionally termed sympatholytics

prevent the action of NE released from nerve endings by competing with NE at receptor site

42
Q

alpha2 inhibition effect on heart rate

A

increases

43
Q

alpha2 inhibition on GI tract

A

increases motility

44
Q

alpha2 inhibition on corpus cavernosum

A

increases erectile function

45
Q

alpha2 inhibitors on CNS

A

stimulant

46
Q

alpha receptor blockers

A

phenoxybenzamine

phentolamine

47
Q

side effects of phenoxybenzamine

A

orthostatic hypotension

nasal congestion

inhibition of emission

inhibition of mydriasis

increases motility (blocks alpha2 on cholinergic nerve endings)

persistent tachycardia (blocks alpha2 on adrenergic nerve endings)

48
Q

alpha1 receptor blockers

A

prazosin - alpha1 selective

tamsulosin - alpha1A selective

alfluzosin - alpha1A selective

silodosin - the most selective alpha 1A antagonist

49
Q

alpha2 receptor blocker

A

disinhibition of neurotransmitter release effects may be similar to nerve stimulation

produces persistent tachycardia by disinhibition of NE release

yohimbine - most selective alpha2 antagonist

50
Q

innervation of the corpus caverosum

A

non-ad-renergic, non-cholinergic (NANC) innervation has alpha receptors on it and is responsible for the stimulation of arousal - alpha2 leads to inhibition of relaxation through NO and PDE5

sympathetic nerves are responsible for detumescence

51
Q

sexual dysfunction treatments

A

drugs of choice are ___denafils or ___afils

prototype is sildenafil (viagra)

selective inhibiotrs of phosphodiesterase type 5 (PDE 5

this causes the breakdown of cGMP

52
Q

beta receptor blockers

A

sometimes called “first generation”

effects are predictable based on the functions of beta receptors

propranolol is the prototype

timolol

53
Q

therapeutic uses of proranolol

A

anti-arrythmic

anti-anginal

antihypertensive-block of renin

pheochromocytoma

stage fright

54
Q

contraindications of propranolol

A

asthmatics need beta2 drive

diabetics, propranolol masks signs of hypoglycemia and decreases glycogenolysis

55
Q

metabolism for beta blockers

A

phase I oxidation by CYP2D6

phase II by glucuronidation and sulfation

56
Q

latanoprost

A

current therapy for glaucoma

PGF2alpha derivative that increases AH outflow by the uveal-scleral route

major side effect - may produce irreversible darkening of the iris and eyelashes

57
Q

beta1 receptor blockers

A

spare bronchioles because it is selective for beta1 receptors at low concentrations

metoprolol

atenolol

betaxolol

esmolol

58
Q

mixed alpha1 and beta blocker

A

beta blockers with additional actions that are sometiems called “third generation”

labetalol - current drug of choice to treat hypertension in pregnancy

carvedilol - durg of choice to treat patients with mild heart failure

Foundations 2 (33 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions