Anti-Adrenergics Drugs

Question 1

which drug is an irreversible blocker of alpha-adrenoceptors?

Answer 1

phenoxybenzamine (covalent bonding)– alpha1 and alpha2

Question 2

what 2 drugs are alpha antagonists (non-selective)?

Answer 2

Phenotolamine

Phenoxybenzamine

Question 3

what 2 drugs are selective alpha1 antagonists?

Answer 3

Prazosin

Tamsulosin

Question 4

Postural hypotension is an adverse effect for which class of drugs?

Answer 4

alpha antagonists (i.e. Prazosin, Tamsulosin, Phentolamine, Phenoxybenzamine)

Question 5

What are the main effects of giving an alpha-antagonist?

Answer 5

1) arterial and venous vasodilation
2) increase in HR (reflex sympathetic stimulation and increase of NE due to blockade of alpha-2 presynaptic adrenoceptors)
3) responses to catecholamines are impaired (i.e. norepi, epi)
4) bladder spinchter relaxation (improvement of urinary flow)
5) increased insulin release (due to blockade of alpha-2 receptors)

Question 6

what would really high doses of phenoxybenzamine result in?

Answer 6

inhibition of cetecholamine reuptake and irreversible block of muscarinic, serotonergic and histaminergic receptors

Question 7

what is the duration of action of pheonxybenzamine?

Answer 7

up to 7 days after discontinuation (time required before the number of alpha receptors return to normal)

Question 8

what are the clinical uses of Prazosin?

Answer 8

1) urinary symptoms BPH (promotes peeing)
2) HTN
3) Raynaud’s disease

Question 9

What are the clinical uses of Tamsulosin

Answer 9

1) urinary symptoms BPH (promotes peeing) - has more receptors on prostate specifically
2) HTN

Question 10

What class of drugs can cause priapism and inhibition of ejaculation?

Answer 10

alpha antagonists

Question 11

What 7 disorders can cause postural hypotension?

Answer 11

1) hypovolemia
2) idiopathic postural hypotension
3) addison disease
4) systemic mastocytosis
5) mitral valve prolapse syndrome
6) familial dysautonomia (Riley-Day syndrome)
7) multiple system atrophy (shy-Drager syndrome)

Question 12

What is the main clinical uses of Phenoxybenzamine?

Answer 12

pheochromocytoma (used preoperatively and for management of inoperable or metastatic cases)

Question 13

What is the main clinical use of Phentolamine?

Answer 13

1) pheocromocytoma (diagnosis)
2) tyramine syndrome
3) clonidine withdrawal

(anytime there is an emergency excess of circulating catecholamines)

Question 14

what are 4 nonselective beta blockers?

Answer 14

propanolol
pindolol
timolol
sotalol

Question 15

what are 3 selective B1 blockers?

Answer 15

atenolol
esmolol
metoprolol

Question 16

what are two A-B blockers?

Answer 16

labetalol

carvedilol

Question 17

what are the CVS effects of beta-blockers?

Answer 17

1) decreased heart contractility
2) decreased CO
3) increased perfusion of subendocardial region of heart

Question 18

what effect do B-blockers have on vessels?

Answer 18

1) vasodilator

BP is not decreased in healthy ppl- only in those with hypertension!

Question 19

B-blockers are especially contraindicated in people with what respiratory conditions?

Answer 19

Asthma and COPD (b-blockers cause bronchoconstriction but it can be lifethreatening in these individuals)

Question 20

what effect do beta-blockers have in the eye?

Answer 20

decreased production of aqueous humor by ciliary epithelium

Question 21

what are the metabolic/endocrine effects of beta-blockers?

Answer 21

1) Decrease release of Renin
2) decreased lipolysis
3) decreased glycogenolysis/ gluconeogenesis
4) decreased K+ uptake by skeletal muscle
5) blockade of catecholamine induced tremor
6) blockade of adrenergic activation due to hypoglycemia

Question 22

what 3 beta-blockers act as local anestethics?

Answer 22

1) propanolol
2) pindolol
3) metoprolol

Question 23

what beta-blocker is a weak b1 and b2 partial agonist?

Answer 23

Pindolol

Question 24

what beta blocker has K+ channel blocking activity?

Answer 24

sotalol

Question 25

What beta-blocker is used for A-fib?

Answer 25

Atenolol

Question 26

What b-blocker has a short half life and is used in emergency siutations for a hypertensive crisis or surgery?

Answer 26

esmolol

Question 27

What are the main clinical uses of beta-blockers?

Answer 27

1) HTN
2) cardiac arrhythmias
3) exertional angina
4) open angle glaucoma
5) acut eMI
6) hyperthyroid
7) hypertrophic cardiomyopathy
8) pheocromocytoma
9) social phobias
10) aortic dissection

Question 28

what is the main pharmacological effects of labetalol and carvedilol (alpha/beta antagonists)

Answer 28

1) decreased TPR
minimal change in HR and CO. the decreased TPR causes reflex tachy that counteracts direct decrease in HR.

used for pregnancy induced hypertension

Question 29

which beta blockers are lipid soluble?

Answer 29

propanolol
metoprolol
labetalol

Question 30

what are the characteristics of lipid soluble beta blockers

Answer 30

low oral bioavailability, large first pass effect, large volume of distribution, cross BBB

Question 31

what beta-blockers are hydrophilic?

Answer 31

atenolol
pindolol
esmolol
sotalol

Question 32

AE’s of b-blockers?

Answer 32

1) peripheral vascular spasms
2) bradyarrhythmias
3) acute HF
4) sithdrawal effects after chornic use (don’t stop abruptly)
5) insomnia, dizziness, nightmares
6) diarrhea
7) bronchoconstriction
8) sexual dysfunction (esp after chronic use)
9) increased probability of hypoglycemic reactions
10) hypertensive crisis
11) hyperkalemia
12) skin rashes

Question 33

Major contraindications of b-blockers

Answer 33

1) abrupt discontinuation
2) asthma/COPD
3) bradyarrhythmias
4) DM
5) acute cardiac failure
6) depression
7) elderly (unpredictable)

Question 34

what is an indirect acting anti-adrenergic drug?

Answer 34

metyrosine

Question 35

what is the MOA of metyrosine?

Answer 35

inhibition of tyrosine hydroxylase (rate-limiting enzyme in catecholamine biosynthesis)

Question 36

what is the clinical use of metyrosine?

Answer 36

preop prep of patients for pheochromocytoma resection

adjuvant to alpha-blocker in patients with inoperable pheochromocytoma