Alpha blockers

Question 1

Alpha 2A locations:

Answer 1

medulla (presynpactic)

Question 2

Alpha 2A stimulation results in:

Answer 2

decreased sympathetic outflow

Question 3

Alpha 2B locations:

Answer 3

vascular smooth muscle

Question 4

Alpha 2B stimulation results in:

Answer 4

vasoconstriction

Question 5

Mechanism of action of Clonidine

Answer 5

ALPHA 2 AGONIST

activation of central presynaptic alpha 2A receptors –> suppression of central symp. outflow

suppression of peripheral presynaptic alpha 2 receptors –> inhibition of NE, ATP, NPY release

Question 6

Effects of Clonidine?

Answer 6

CNS - decreases BP (HR, SV decrease and relaxation of capacitance vessels)

Renal - decreases renin (alpha 2 stimulation)

Eyes - decreases IOP

Question 7

Abrupt discontinuation of clonidine after high dosage prolonged use can result in

Answer 7

hypertensive crisis

Question 8

Major therapeutic use of clonidine?

Minor?

Answer 8

Major: hypertension

Minor: decrease diarrhea in diabetics with autonomic neuropathy;
treatment of withdrawal of opiate addicts (their bp may increase);
menopausal hot flashes

Question 9

MoA of methyldopa?

Answer 9

ALPHA 2 AGONIST

a-methylnorepinephrine (metabolite) stimulates alpha 2 receptors in brainstem

Question 10

Effects of methyldopa?

Answer 10

CVS - decreases PVR. (little change in CO and HR)

renal system - decreases renin secretion (alpha 2)

Question 11

Most common side effect of methyldopa?

Answer 11

sedation.

Also, dry mouth.

Question 12

Which adrenergic drug causes a positive Coombs test?

Answer 12

methyldopa

Question 13

Which alpha 2 agonist is used to decrease IOP?

Answer 13

apraclonidine

brimonidine

Question 14

Which alpha 2 agonist is used as a muscle relaxant for treatment of spasticity?

Answer 14

Tizanidine

Question 15

Which alpha 2 agonist is used as an anti-MI drug

Answer 15

Mivazerol

Question 16

Which alpha 2 agonist is used to treat HTN AND ADHD in 16-17 year olds

Answer 16

Guanfacine

Question 17

Result of alpha 1 blockage:

Answer 17

Beta 2 unopposed - vasodilation and decrease of PVR and BP

Question 18

Result of alpha 2 blockage

Answer 18

presynaptic –> inhibition of inhibition of NE –> INCREASES NE –> B1 in heart and JG cells stimulated –> INCREASED HR and renin release

Question 19

Alpha blocker used as diagnostic test for pheochromocytoma?

Answer 19

phentolamine

Question 20

Major adverse affect of phentolamine

Answer 20

hypotension (can result in reflex tachycardia)

Question 21

Alpha antagonist with 100x greater selectivity for alpha 1 over alpha 2. Used in pheochromocytoma

Answer 21

phenoxybenzamine

Question 22

What used to treat HTN crisis following clonidine withdrawal?

Answer 22

phentolamine

Question 23

What general drug class is used to treat pseudo-obstruction of the bowels

Answer 23

alpha blocker

Question 24

What is used to treat dermal necrosis?

Answer 24

phentolamine

Question 25

What is used to treat Raynaud's phenomenon

Answer 25

PBZ or prazosin (CCB preferred)

Question 26

List 5 selective alpha 1 blockers

Answer 26

``` Prazosin Terasozin Doxazosin Tamsulosin Alfuzosin ```

Question 27

Which drugs have alpha 1ABD selectivity?

Answer 27

Prazosin, terazosin, doxazosin

Question 28

Which drugs have alpha 1A selectivity

Answer 28

Tamsulosin, alfuzosin

Question 29

Alpha 1A found in

Answer 29

prostate, bladder neck

Question 30

Alpha 1B found in

Answer 30

blood vessels

Question 31

Which selective alpha 1 blocker is not a quinazoline?

Answer 31

Tamsulosin

Question 32

Which selective alpha 1 blockers induce apoptosis in prostate

Answer 32

terazosin, doxazosin

Question 33

Which selective alpha 1 blockers treat only BPH and not HTN?

Answer 33

Tamsulosin, alfuzosin

Question 34

Which selective alpha 1 blocker is used in SHORT term treatment of CHF?

Answer 34

Prazosin

Question 35

Which selective alpha 1 blockers are more prone to the first-dose effect?

Answer 35

Prazosin, terazosin, doxazosin

Question 36

Alpha 1 blockers dilate or constrict blood vessels?

Answer 36

Dilate

Question 37

Selective alpha 2 blocker sold as dietary supplement.

Answer 37

Yohimbine (increases BP/HR, produces tremors)

Question 38

Which ergot alkaloids are used in uterine atony postpartum/postpartum hemorrhage?

Answer 38

ergonovine/methylergonovine (causes uterine contraction)

Question 39

Which ergot alkaloid is used in migraines?

Answer 39

ergotamine/dihydroergotamine

Question 40

What is cafergot?

Answer 40

ergot alkaloid + caffeine to facilitate absorption

Question 41

Which ergot alkaloids decrease prolactin secretion?

Answer 41

cabergoline, bromocriptine (high selectivity for pituitary dopamine receptors)

Question 42

Which ergot alkaloid is used in senile cerebral insufficiency?

Answer 42

dihydroergotoxine

Question 43

Which ergot alkaloid is used in parkinsonism?

Answer 43

Bromocriptine (as a dopamine agonist)

Question 44

Prolonged vasospasm caused by ergotamine or ergonovine can result in:

Answer 44

gangrene

Question 45

Imidazoline agonist, anti-hypertensive. Acts on rostral ventro-lateral pressor and ventromedial depressor areas of the medulla oblongata.

Answer 45

Moxonidine | Rilmenidine

Question 46

Difference between brimonidine and aproclonidine?

Answer 46

Brimonidine crosses BBB, but not apraclonidine

Question 47

The only alpha 2 antagonist studied

Answer 47

yohimbine