Sweatman Alpha Blockers

Question 1

Alpha Blocking Agents

3-Major

Answer 1

Doxazosin (cardura)
Terazosin (hytrin)
Parzosin (minipress)

Question 2

Alpha Blocking agents (2-Minor)

Answer 2

Phenoxybenzamine (dibenzyline)

Phentolamine (regitine)

Question 3

Agent in the major Alpha Blocker Class that due to PK’s is less amenable for therpy

Answer 3

phentolamine a1=a2 and phenoxybenzamine

Question 4

intended effect of alpha antagonists

Answer 4

vasodilation

Question 5

Why are phenoxybenzamine and phentolamine limited in clinical use

Answer 5

they inhibit alpha 1 and alpha 2 and can actually cause cardiac stimulation and unintended vasoconstriction

Question 6

alpha 2 receptors are located…

Answer 6

presynaptically

Question 7

alpha 1 receptors are located

Answer 7

postsynaptically

Question 8

alpha 2 receptors function as

Answer 8

autoreceptors

Question 9

alpha 1 receptors function in

Answer 9

down stream signalling

Question 10

norepinephrine is tropic for

Answer 10

alpha-1, 2 receptors

Beta-1

Question 11

epinephrine is tropic for

Answer 11

alpha 1 and 2 and beta 1 and 2 receptors

Question 12

beta receptors cause

Answer 12

vasodilation

Question 13

alpha receptors result in

Answer 13

vasoconstriction

Question 14

SA node is accelerated by what type of receptors

Answer 14

B1 and 2

Question 15

ectopic pacemakers are accelerated by what type of receptors

Answer 15

B1 and 2

Question 16

contractility is increased by via which S receptors

Answer 16

B1 and 2 receptor

Question 17

BV’s in skin are contractes by Sympa. acting on

Answer 17

alpha receptors

Question 18

BV’s in skeletal muscle is relaxed by what type of receptors

Answer 18

beta 2

Question 19

BV’s in skeletal muscle are contractes by acting on which type of receptor

Answer 19

alpha

Question 20

ALpha 1 receptors work via

Answer 20

activation of the receptor increasing DAG and IP3 leadings to increased intracellular calcium–>propagation of signal

Question 21

isoprotorenol tropic for

Answer 21

beta-1and 2

Question 22

alpha receptors mainly block the BP increases caused by

Answer 22

norepinephrine acting on alpha receptors

prevents vasoconstriction

Question 23

Beta blockers lower blood pressure by

Answer 23

blocking the effects of EPINEPHRINE onto alpha receptors
*in the presence of a normally functioning beta relaxation-> low blood pressure in the absence of the normal alpha vasoconstriction

Question 24

Pre-treatment with a beta blocker in the presence of epinephrine

Answer 24

rise in BP

Question 25

pretreatment with alpha blocker in presence of isoproterenol

Answer 25

no affect--> it acts on Beta receptors--> will vasodilate and reduce BP

Question 26

A1>>>A2

Answer 26

terazosin, doxazosin, prazosin | *inhibits downstream signaling

Question 27

A1>A2

Answer 27

phenoxybenzamine

Question 28

a1=a2

Answer 28

phentolamine

Question 29

Alpha 1a utility

Answer 29

bladder neck and prostate -->reduce BPH and increase urine flow rate

Question 30

Alpha 1a drug useful in BPH

Answer 30

alfuzosin

Question 31

principle issue with alpha blockers

Answer 31

too rapid of a reduction in BP leading to orthostatic hypotension

Question 32

most prominent OH causing alpha blocker

Answer 32

prazosin

Question 33

second most common adverse effect os alpha 1 drugs

Answer 33

cross-talk inhibition of alpha 2 pre-synaptic receptors | -->receptor specificity is never 100%

Question 34

Adverse effects of alpha 2 blockade by alpha 1 tropic agents

Answer 34

with high doses-->autoreceptors are effected inhibition of the feedback regulation-->leads to increased released of norepinephrine-->overstimulation of CV system in the form of tachycardia

Question 35

alpha blockers with longerhalf life

Answer 35

*regimens=once/daily doxazosin-->22hrs terazosin-->12 hrs

Question 36

alpha blocker that covalently binds and it non-competitive

Answer 36

phenoxybenzamine

Question 37

side effects of phenoxybenzamine

Answer 37

-->nasal congestion -->tachycardia *alpha one and 2 antagonist so antiagonizes circulating E and NE on VSM while increasing release of NE-->increases CO and tempering BP lowering action

Question 38

other side effects of phenoxybenzamine

Answer 38

drowsiness, fatigue, weakness, mailaise, confusion, headache, xerostome, and ejaculatory dysfunction

Question 39

short onset-->long duration

Answer 39

phenoxybenzamine

Question 40

short acting competitive antagonist

Answer 40

phentolamine

Question 41

indications for phenoxybenzamine

Answer 41

pheochomrocytoma

Question 42

indications for phentolamine

Answer 42

pheochromocytoma and hypertensive emergency

Question 43

small doses of phentolamine...

Answer 43

positive inotropic effect -->increasing BP

Question 44

larger doses of phentolamine...

Answer 44

peripheral Vasodilation---> decreased BP

Question 45

prominent feature of phentolamine

Answer 45

POSTURAL HYPOTENSION and reflex tachycardia-->precipitating cardiac arrythmias