Adrenergic Antagonists Flashcards Preview

Pharmacology Test #2 > Adrenergic Antagonists > Flashcards

Flashcards in Adrenergic Antagonists Deck (92):
1

What is a synonym for adrenergic antagonists?

sympatholytics

2

What are the 2 broad classes of alpha-receptor antagonists?

Reversible

Irreversible

3

Who do alpha-receptor reversible antagonists compete with?

agonists

endogenous catecholamines

4

Describe the mechanism of alpha-receptor reversible antagonists

block receptor and dissociate if agonist is present in high enough concentration

5

What is a alpha-receptor reversible antagonist duration of action dependent on?

drug's affinity for receptor

1/2 life of drug in the body

6

How do alpha-receptor irreversible antagonists bind?

form covalent bonds = permanent block

7

What is the alpha-receptor irreversible antagonist duration of action dependent on?

dependent on synthesis of new receptors (up to several days)

8

What do alpha-antagonists do in the cardiovascular system?

block alpha1-mediated vasoconstriction --> vasodilation --> decrease in peripheral vascular resistance and decrease in BP

9

What is a side effect of alpha-antagonists in the cardiovascular system?

orthostatic hypotension (body's ability to adjust peripheral vascular resistance has been blocked

reflex tachycardia (response to maintain cardiac output; compensatory mechanism to drop in BP)

10

What are some other effects of alpha1 antagonists?

block mydriasis --> mitosis

block nasal vasoconstriction --> sinus congestion

block alpha-mediated urinary retention --> facilitates urination

11

What is phenoxybenzamine and what does it do?

alpha antagonist

irreversible blockade of alpha1 receptors (more so than alpha2 receptors)

12

What is the effect of phenoxybezamine?

blocks vasoconstriction --> vasodilation

also blocks presynaptic alpha2 receptors (blocks reuptake of norepinephrine (not as potent an effect))

13

What is phenoxybezamine used to treat?

conditions of excessive catecholamine release --> pheochromocytoma (adrenal gland tumor)

14

What are the symptoms of pheochromocytoma that are treated by phenoxybezamine?

over secretion of norepinephrine and epinephrine --> hypertension, headaches, palpitations, sweating

15

What is phentolamine?

reversible blockade of alpha1 receptors and presynaptic alpha2 receptors

16

What is the effect of phentolamine?

alpha1 blocking = decrease peripheral vascular resistance

alpha2 blocking due to increase in cardiac stimulation --> increase HR increase cardiac workload, potential for arrhythmias (due to increase norepinephrine activity b/c blocked norepinephrine reuptake)

17

What is phentolamine used for?

management of pheochromocytoma

18

What are some other examples of alpha1 antagonists?

Prazosin

Terazosin

Doxazosin

Tamsulosin

19

What is a side effect of prazosin?

orthostatic hypertension

20

What is tamsulosin used for?

enlarged prostate

HTN

BPH

21

What is the effect of tamsulosin?

relaxation of arterial/venous smooth muscle --> HTN

relax smooth muscle in prostate (most selective for this)

22

Some drugs have alpha1 antagonistic as a secondary mechanism of action, in these drugs what is the side effect that you'll most likely see?

hypotension

23

What are some examples of drugs that have alpha1 antagonistic side effects and what are they usually used for?

Haloperidol = antipsychotic

Chlorpromazine = antipsychotic

Trazodone = sleep aid and antidepressant

Ergotamine and dihydroergotamine = migranes

24

How do beta-receptor antagonists bind to their receptors?

Reversibly

25

Are beta-receptor antagonists pure antagonists?

Most are, however some do have some beta-agonist activity (but usually only w/ low concentrations of endogenous catecholamines)

some have local anesthetic properties

26

Can beta-receptor antagonists be selective?

Yeah, differ in affinity and selectivity for blocking beta1 or beta2

However, selectivity will decrease w/ higher doses

27

Are there pharmacokinetic differences between beta-receptor antagonists?

Yeah, differences between distribution, 1/2 life, and elimination route

28

What are beta antagonists usually called in the cardiovascular system?

Beta blockers

29

What are beta antagonists used for in the cardiovascular system?

control high BP

angina

CHF

MI

30

What is the mechanism of action of beta-antagonists in the control of high BP?

complex and unclear mechanism

suppression of renin release

CNS actions

debatable first-line agent for high BP

31

What is the mechanism of action of beta antagonists in the control of angina, CHF, MI?

part of first-line therapy

reduce cardiac workload (negative inotropic, negative chronotropic effects)

slow AV node conduction --> decrease HR

suppress renin release

32

What is the net effect of beta-antagonists in the treatment of angina, CHF, or MI?

reduce peripheral vascular resistance, BP, overall workload of the heart

33

Why is it surprising that beta-antagonists (or blockers) decreases BP?

block peripheral Beta2 receptors --> expect inhibit vasodilation BUT w/ long term use BP decreases (unclear mechanism)

34

What can enhance vasodilation properties of beta antagonists?

drugs that also block alpha1 receptors

nonselective agents --> greater drop in BP b/c block vasoconstriction

35

What is an example of a nonselective adrenergic antagonist that is used to treat high BP?

labetolol --> blocks alpha and beta; blocks vasoconstriction

36

Why are beta antagonists used to treat angina?

help pts by improving balance between oxygen supply and demand

37

Describe the mechanism of beta blockers when treating angina

block adrenergic effects of sympathetic nervous system --> reduce cardiac workload --> reduce demand of oxygen

improves exercise tolerance by preventing heart from working to hard

38

Why are beta antagonists contraindicated for use in pts w/ asthma and COPD?

No pure beta1 blockers available --> inadvertently block beta2 receptors (which facilitate bronchodilation)

39

Which class of drugs would you want to use to treat COPD and asthma instead of beta antagonists?

Beta agonists

40

Which opthalmic disease are beta blockers used to treat?

open-angle glaucoma --> reduce production of aqueous humor --> reduce intraocular pressure

41

What are some examples of beta blockers that are used to treat glaucoma and how are they given?

Eye drops

Betaxolol

Timolol

Carteolol

Levobunolol

42

What are some side effects of beta blockers?

block glucose mobilization

worsen high cholesterol

intrinsic sympathomimetic activity

local anesthetic activity

43

What does it mean to block glucose mobilization?

reduce energy availability

inhibit sympathetic-mediated stimulation of lipolysis

partial inhibitor of glycogenolysis --> block body's availability to make glucose when needed (hypoglycemia)

44

Why would you want to use caution with beta blockers use in an insulin dependent diabetics?

beta blockers mask symptoms of hypoglycemia --> pts won't know when sugars drop

Hypoglycemic symptoms= tachycardia/sweating

45

What are some of the cholesterol issues caused by beta blockers?

some types of stored cholesterol levels are altered --> increase cardiovascular risk and coronary artery disease

increase VLDL (very low density lipoproteins aka bad kind)

decrease HDL (high density lipoproteins aka good kind)

46

Which types of beta blockers can cause cholesterol issues?

Both selective and nonselective beta blockers

47

Which types of beta blockers have intrinsic sympathomimetic activity (ISA)?

beta blocker that has partial beta agonist activity (structural thing)

48

What is a good thing about about intrinsic sympathomimetic activity?

may decrease negative features of beta blockers --> i.e. bronchoconstriction and bradycardia

49

What is a bad thing about intrinsic sympathomimetic activity?

may reduce the therapeutic effects of beta blockers --> especially cardioprotective benefits

50

What are 3 examples of beta blockers with intrinsic sympathomimetic activity?

Labetolol

Pindolol

Acebutolol

51

What is another term for local anesthetic action of beta blockers?

membrane stabilization

52

What is the mechanism of local anesthetic action of beta blockers?

blockade of Na+ channels in axon of nerves --> prevent electrolytic excitation of the nerve/depolarization/transfer of sensation info

53

What are some examples of beta blockers with local anesthetic action?

Acebutolol

Labetolol

Pindolol

Propranolol

54

What are the 7 major uses of beta blockers?

Hypertension

Ischemic heart disease

Arrhythmias

Heart failure

Glaucoma

Migrane headaches

Performance anxiety

55

When are beta blockers considered a first line option in treating hypertension?

in patients w/ compelling indications (comorbidities)

56

What are the comorbidities that indicate use of beta blockers in treatment of hypertension?

Heart Failure

post-MI

Angina

Diabetes

among others

57

What are considered the most important beta blockers used for hypertension?

Atenolol

Metoprolol

58

Name the other beta blockers used for hypertension?

Bisoprolol

Nadolol

Pindolol

Plus others

59

Would you use beta blockers to treat hypertension if a patient didn't have the comorbidities?

No --> beta blockers aren't considered first line for these patients

60

What causes ischemic heart disease?

cholesterol plaques in cardiac arteries--> decrease blood flow and oxygen delivery

61

What types of symptoms would pts with ischemic heart disease have?

Angina

Poor exercise tolerance

62

What are the effects of beta blockers in patients with ischemic heart disease?

decrease cardiac workload (slow HR, decrease strength of heart squeeze) --> less demand for O2 (limited supply meets less demand)

63

When are beta blockers considered first line to treat ischemic heart disease?

pts @ risk or after MI

history of angina

history of left ventricular dysfunction

64

What are the 2 beta blockers used to treat ischemic heart disease?

propranolol

metoprolol

65

What is an arrhythmia?

abnormal electrical rhythm w/in the heart muscle

decrease heart functionality

can be fatal

66

What types of arrythmias are beta blockers used to treat?

supra-ventricular arrhythmias

ventricular arrhythmias

atrial fibrillation

atrial fluttering

67

What are the physiologic effects of beta blockers that are useful in the treatment of arrhythmias?

extend the resting period of AV nodal cells

slow ventricular response to electrical stimulation --> stop abnormal rhythm (hopefully)

68

Are beta blockers the first line treatment of arrhythmias?

No, usually used after other meds have failed

69

What are the 2 beta blockers that are used to treat arrythmias?

metoprolol

sotalol

70

Which type of heart failure are beta blockers used for?

CHRONIC heart failure

71

What are some examples of beta blockers that are used to treat chronic heart failure?

metoprolol

bisprolol

carvedilol

72

What type of eye disease are beta blockers used to treat?

Glaucoma

73

What is the method of administration of beta blockers when treating glaucoma?

administered directly to the eye

74

What are the effects of beta blocks in the eye (aka why are they used to treat glaucoma)?

inhibits the production of aqueous humor

75

What are some examples of beta blockers that are used to treat glaucoma?

Timolol

Betaxolol

Carteolol

Levobunolol

76

What are some of the side effects of beta blockers that are used to treat glaucoma?

cardiac/pulmonary effects --> systemic absorption

77

What is hyperthyroidism (very general), and what can it lead to?

overactive thyroid

lead to excessive catecholamine action --> tachycardia

78

What are the effects of beta blockers that are useful in treating hyperthyroidism?

decrease symptoms by blocking adrenergic receptors

decrease conversion of thyroxine (T4) --> triiodothyronine (T3) (t3 = active thyroid hormone)

79

What is an example of a beta blocker that is used to treat hyperthyroidism?

Propranolol

80

Which beta blockers are used to treat migraine headaches?

metoprolol

propranolol

81

How do beta blockers treat migraine headaches?

reduce frequency and/or intensity

82

What is a synonym of performance anxiety?

stage fright

83

How do beta blockers treat performance anxiety?

eliminate symptoms induced by stress and anxiety:

slow HR

reduce palmar sweating

84

What are some complications of liver disease?

cirrhosis

portal vein hypertension

85

What are some effects of beta blockers that are useful in treating hepatic diseases?

can have targeted effect to reduce the elevated BP

86

What are 2 beta blockers that are used to treat hepatic disease?

Nadolol

Propranolol

87

What are some major side effects of beta blockers?

Bradycardia

Worsening of asthma (beta2 in lungs)

worsen cardiac output in pts w/ heart failure

exacerbation of hypoglycemia in diabetics

88

What are some of the minor/less common side effects of beta blockers?

mild sedation

vivid dreams

depression

89

Overall why do you want to use caution with the use of beta blockers?

the response of pts to beta blockers can be unpredictable

90

What is the most important thing about stopping the use of beta blockers?

NEED TO TAPER PTS OFF BETA BLOCKERS

91

Why do you need to taper pts off of beta blockers?

abrupt discontinuation can lead to rebound hypertension (esp. in pts being treated for ischemic heart disease or hypertension)

92

What needs to be considered when choosing a beta blocker?

Safety issues (side effects)

Partial agonist activity

local anesthetic properties (not a huge concern)

differences in renal/hepatic metabolism

differences in elimination half-life