Adrenergic Receptor Antagonists

Question 1

Phentolamine (Regitine)

Answer 1

Class: Non-selective α-antagonist
MOA: Antagonist: α1, α2
Uses: Pheochromocytoma, Raynaud’s, frostbite
SE: Postural hypotension; inhibit ejaculation

Question 2

Phenoxybenzamine (Dibenzyline)

Answer 2

Class: Non-selective α-antagonist
MOA: Antagonist: α1, α2; non-competitive blocker (covalent bond to receptor)
Uses: Pheochromocytoma, Raynaud’s, frostbite
SE: Postural hypotension; inhibit ejaculation

Question 3

Prazosin (Minipress)

Answer 3

Class: α1-selective antagonist
MOA: Antagonist: α1
Uses: Primary HTN, BPH
SE: Postural hypotension (usually 1st dose)

Question 4

Propranolol (Inderal)

Answer 4

Class: Non-selective β-antagonist
MOA: Antagonist: β1, β2
Uses: Angina, Hypertension, Arrythmias
SE: Bradycardia, Bronchoconstriction, Sexual Dysfunction
Misc: Workhorse by which all the rest are judged

Question 5

Timolol (Betimol)

Answer 5

Class: Non-selective β-antagonist
MOA: Antagonist: β1, β2
Uses: Glaucoma
SE: Bradycardia, Bronchoconstriction, Sexual Dysfunction

Question 6

Metoprolol (Lopressor)

Answer 6

Class: β1-selective antagonist (2nd generation)
MOA: Antagonist: β1
Uses: HTN, Angina, Arrythmias, CHF
SE: Bradycardia, Sexual Dysfunction

Question 7

Atenolol (Tenormin)

Answer 7

Class: β1-selective antagonist (2nd generation)
MOA: Antagonist: β1
Uses: HTN, Angina, Arrythmias, CHF
SE: Bradycardia, Sexual Dysfunction

Question 8

Carvedilol (Coreg)

Answer 8

Class: Non-selective β-antagonist (3rd generation “A”)
MOA: Antagonist: β1, β2
Uses: CHF, HTN
SE: Bradycardia, Fatigue

Question 9

Labetalol (Trandate)

Answer 9

Class: Non-selective β-antagonist (3rd generation “A”)
MOA: Antagonist: β1, β2
Uses: CHF, HTN
SE: Bradycardia, Fatigue

Question 10

Tyramine

Answer 10

Class: Indirect acting agonist
MOA: Increases cytoplasmic NE release

Misc:Tyramine is involved with an exchange transporter: tyramine goes in, NE comes out

Question 11

Cocaine

Answer 11

MOA: Prevents NE reuptake
Uses: Local anesthetic, vasoconstrictor
SE: Insomnia, anxiety, arrhythmias

Question 12

Guanethidine (Ismelin)

Answer 12

Class: Nerve ending blocker
MOA: False neurotransmitter (vesicles become full of guanethidine rather than NE)
Uses: Antihypertensive
SE: Many and serious

Question 13

Reserpine

Answer 13

Class: Nerve ending blocker
MOA: Release of empty vesicles (NE is not taken into vesicles b/c it binds uptake transporter and stops it)
Uses: Antihypertensive
SE: Many and serious (depression and suicide are major ones)

Question 14

α-me-tyrosine (Metirosine)

Answer 14

Class: Nerve ending blocker
MOA: Inhibit tyrosine hydroxylase (decreases NE synthesis)
Uses: Pheochromocytoma
SE: Many and serious

Question 15

Ephedrine (Pretz-D)

Answer 15

Class: Mixed, direct (β2)/indirect agonist

Uses: Nasal decongestion, anorexic