Adrenergic Agonists and Antagonists Flashcards Preview

PNS/Cardiology > Adrenergic Agonists and Antagonists > Flashcards

Flashcards in Adrenergic Agonists and Antagonists Deck (39)
Loading flashcards...
1
Q

What are the indirect acting NE releasers?

A

Tyramine
Amphetamine
Ephedrine

2
Q

Where is tyramine normally found?

A

Diet, aged/fermented foods like cheese and wine

3
Q

Why does dietary tyramine not normally cause NE release?

A

Normally oxidized by MAO in gut and liver before reaching the circulation
MAO-I inhibitors will allow NE release

4
Q

What are amphetamines used to treat?

A

Narcolepsy and ADD

5
Q

What is the mechanism of action of ephedrine?

A

NE releaser and weak Beta2 agonist

6
Q

What are the uses of ephedrine?

A

Decongestant
Vasopressor (BP increased)
Stress urinary incontinence (contracts bladder sphincter)

7
Q

What is the difference between ephedrine and pseudoephedrine?

A

Less psychostimulant

Less CV effects with equivalent decongestant potency

8
Q

What is the mechanism of NE release caused by the indirect acting NE releasers?

A

Nonvesicular release
NE-releaser displaces NE from vesicle to cytoplasm
NE released by reversal of NET

9
Q

What is the mechanism by which cocaine increases NE?

A

Blocks neuronal NE uptake by NET

10
Q

What is the direct-acting Alpha1 agonist?

A

Phenylephrine

11
Q

What are the uses of phenylephrine?

A

Decongestant, vasoconstriction, mydriasis

12
Q

What are the direct-acting Alpha2 agonists?

A

Clonidine

Brimonidine

13
Q

What is clonidine used for?

A

Reduces sympathetic activity by inhibiting NE release (alpha2 receptors are autoreceptors)
Used for hypertension

14
Q

What is Brimonidine used for?

A

Analog of clonidine, used to treat IOP

15
Q

What are the direct-acting Beta2 agonists?

A

Albuterol
Salmeterol
Formoterol
Ritodrine

16
Q

Which beta2 agonists are used for asthma?

A

Albuterol
Salmeterol
Formoterol

17
Q

What is Ritodrine used for?

A

Delay preterm labor

18
Q

What is the direct-acting Beta3 agonist?

A

Mirabegron

19
Q

What is Mirabegron used for?

A

Treat overactive urinary bladder syndrome by relaxing the detrussor

20
Q

What are Alpha 1 & 2 antagonists?

A

Phenoxybenzamine

Phentolamine

21
Q

What are the Alpha 1 & 2 antagonists used for?

A

Management of pheochromocytoma (catecholamine-secreting tumors)

22
Q

What is important to remember about the treatment of pheochromocytomas?

A

Alpha block must be in place before use of a beta block

If beta receptor was blocked first, would cause huge vasconstriction and increased blood pressure

23
Q

What are the Alpha 1 specific antagonists and which is Alpha-1A selective?

A

Prazosin
Terazosin
Tamsulosin - Alpha-1A selective

24
Q

What are prazosin and terazosin used for?

A

Primary hypertension - causes vasodilation
Vasodilation in peripheral vascular disease (Raynaud’s)
Relaxation of urinary tract smooth muscle - helpful in benign prostatic hypertrophy and voiding kidney stones

25
Q

What is tamsulosin used for?

A

Selective relaxant of urinary tract smooth muscle with less vasodilator

26
Q

What is the Alpha 2 selective antagonist?

A

Yohimbine

27
Q

What is yohimbine used for?

A

Increased NE release and increased vasoconstriction

28
Q

What are adverse effects of alpha 1 block?

A

Postural hypotension
Nasal congestion
Dry mouth
Intraoperative floppy iris syndrome (IFIS)
Retrograde ejaculation (relaxed internal sphincter allows it back up)
Delayed ejaculation (reduced propulsion of seminal fluid along vas deferens
Priapism

29
Q

Why does alpha 1 block cause priapism?

A

Sympathetic adrenergic input and contraction of vascular and trabecular smooth muscle maintains flaccidity
Blockage of sympathetic tone relaxes blood vessels, facilitating inflow of blood and compressing veins that are draining blood, resulting in engorgement and rigidity

30
Q

What are the non selective Beta blockers?

A

Propanolol
Timolol
Pindolol

31
Q

What are cardiovascular indications for the use of Beta blockers?

A
Typical effort angina
Postinfarction
Arrhythmias
Systolic heart failure
Primary hypertension
32
Q

What are other indications (not CV) for the use of beta blockers?

A

Hyperthyroidism
Migraine
Glaucoma
Tremors

33
Q

What are the Beta-1 selective blockers?

A

Atenolol

Metoprolol

34
Q

What are the nonselective beta blockers with additional vasodilator actions?

A

Carvedilol

Labetalol

35
Q

Through what receptor does Labetalol exert its additional vasodilator effects?

A

Alpha 1

is an alpha1 & beta blocker

36
Q

Which nonselective beta blocker is also a partial beta agonist and why is this useful?

A

Pindolol

Partial agonism may be advantageous in patients with bradycardia or partial conduction block

37
Q

Which nonselective beta blocker has high lipid solubility?

A

Propranolol

Allows it to cross BBB, placenta

38
Q

What are cardiovascular adverse effects of beta blockers?

A
Decreased exercise capacity
Bradycardia
AV conduction block
Heart failure
Peripheral vasoconstriction (cold extremities)
Withdrawal beta-supersensitivity
39
Q

What are non-CV adverse effects of beta blockers?

A

Bronchoconstriction (contraindicated in asthma/COPD)
Mast cell destabilization (dumping of inflammatory mediators, complicates treatment of anaphylaxis with epi)
Exercise induced hyperkalemia