alpha and beta receptors

Question 1

levonordefrin

Answer 1

alpha-1 agonist, sometimes used as a vasoconstrictor in conjunction with a local anesthetic

Question 2

metaraminol

Answer 2

alpha-1 agonist, used to treat hypotention during surgery

Question 3

alpha-1 agonists

Answer 3

• produce constriction of vascular smooth muscle resulting in BP increase
• commonly used in oral or topical decongestants or in eye drops to diminishly bloodshot eyes

Question 4

alpha-2 agonists

Answer 4

• primarily act on the CNS by inhibiting E and NE from presynaptic terminal
• wide variety of effects

Question 5

clonaidine, guanabenz, guanfacine, methyldopa

Answer 5

alpha-2 agonists to treat hypertension via autonoim regulation of the cardiovascular system (part of CNS feedback loop, not first line of defense)

Question 6

tizanidine

Answer 6

alpha-2 agonist used as muscle relaxant

Question 7

clonidine

Answer 7

alpha-2 agonist used to treat ADHD

Question 8

dexmedetomidine

Answer 8

alpha-2 agonist used as sedative

Question 9

beta-1 agonists are used primarily to treat_________ via_______________.

Answer 9

heart failure and cardiogenic shock via direct stimulation of beta-1 receptors

Question 10

beta-2 agonists are used primarily to treat_________

Answer 10

respiratory disease (asthma) but can be used to produce vasodialation in muscle and liver and to relax uterine tissue.

Question 11

beta-1 agonist examples

Answer 11

denopamine, dobutamine, xamoterol, isopernaline (b2 and b2)

Question 12

beta-2 agonist examples

Answer 12

albuterol, pirbuterol, isoprenaline (b1 and b2), formoterol, clenbuterol

Question 13

alpha-2 agonists CNS disturbances

Answer 13

dizziness, drowsiness, xerostomia, constipation, sexual dysfunction, rebound hypertension if drugs withdrawn suddenly

Question 14

prazosin

Answer 14

alpha-1 selective antagonist to treat hypertenstion

Question 15

alfuzosin

Answer 15

alpha-1 selective antagonist that acts on smooth muscle of prostate (BPH drug)

Question 16

tamulosin

Answer 16

selective alpha-1a and alpha-1d antagonist, selective for prostate, BPH tx, does not increase BP

Question 17

non-selective alpha adrenergic receptor antagonist mechanism

Answer 17

• block transmitter mediated feedback loop which limits transmitter release
• alpha2 specific antagonists have limited application in human clinical medicine

Question 18

phentolamine

Answer 18

• non-selective alpha antagonist
• intravenous infusion used to control hypertension episodes during surgery for patients with pheochromocytoma
• side effects limit usefulness (reactions, reflex tachycardia)
• • used to reverse soft tissue numbness after local anesthetic injection once pain relief not needed

Question 19

phenoxybenzamine

Answer 19

• non-selective alpha antagonist
• irreversible blocker of alpha-1 and alpha-2 receptors
• used to treat pts. with pheochromocytoma

Question 20

beta blocker types currently used

Answer 20

beta-1 or beta-2 nonselective, or beta-1 selective

Question 21

beta blockers increase or decrease heart rate, contraction rate and blood pressure

Answer 21

decrease

Question 22

beta blockers increase or decrease renin release from kidney

Answer 22

decrease

Question 23

beta blockers w/o ISA

Answer 23

decrease, HR, renin and CO

Question 24

beta blockers w/ ISA

Answer 24

• same fxns, but not as good as BB w/o ISA

- decrease agonist driven increases

Question 25

beta blocker common uses

Answer 25

hypertension (renin system) ischemic heart disease (reduce oxy by reducing CO) post-myocardial infarction (reduce oxy by reducing CO) CHF (reduce catacholamine output) arrhythmias

Question 26

beta blocker other uses

Answer 26

- reduce vitreous humor production to tx glaucoma | - in CNS to tx migrane and tremos from anxiety

Question 27

labetalol

Answer 27

- beta blocker w/ both alpha and beta receptor antagonist - ISA activity - 7x more potent as a beta blocker - longterm hypertension management

Question 28

carvedilol

Answer 28

- beta blocker w/ both alpha and beta receptor antagonist - no ISA activity - CHF tx - antioxidant activity

Question 29

adverse beta blocker effects

Answer 29

- heart: bradycardia, AV block. withdrawal leads to angina, heart attack, death - smooth muscle: nonselective blockers can reduce vasodilatory responses, increase bronchospasms - metabolic: hypoglycemia (block epi mediated compensation) - CNS: depression, drowsiness etc.

Question 30

** alpha blockers can cause ________ hypotension. special care should be taken for pts. taking hypertension drugs

Answer 30

orthostatic

Question 31

**nonslective beta blocker pts. are more at risk for a ________ after receiving local anesthetic with vasocontrictor. (doesn't get beta-2 mediated vasodialation to counteract alpha mediated vasocontriction)

Answer 31

hypertensive episode

Question 32

**clonidine causes ________.

Answer 32

xerostomia