Adrenergic Antagonists Flashcards
T or F
A2 receptor blockade leads to tachycardia
True. It eliminates negative feedback which leads to more NE release.
Name 2 non selective Alpha receptor antagonists.
Phentolamine and Phenoxybenzamine
___ and ____ are almost exclusively for the mgmt of pheochromocytomas
Phentolamine and Phenoxybenzamine
____ reversibly binds to alpha receptors, causes vasodilation, is a treatment for NE extravasation and is a reversal of LA injection
Phentolamine
___ irreversibly binds to alpha receptors and an overdose of this drug is treated with NE
Phenoxybenzamine
Non specific B antagonist.
Main indication = thyroid storm (thyrotoxicosis) and Pheos.
No longer commonly used
Side effects = bronchospasm, CHF and AV heart block.
Withdrawal syndrome = rebound HTN, tachycardia and angina
Propranolol (Inderal)
___ is a non selective beta antagonist that has been associated with rebound HTN, tachycardia and angina when patients stop taking it due to the up-regulation of beta receptors
Propranolol (Inderal)
What type of beta blocker should be used in pts w/ reactive airway disease?
B1 selective antagonist
____ is an ultra short acting B1 selective antagonist.
Esmolol (BreviBloc)
Mixed antagonist (A1 B1 and B2). Decr PVR and renin, some decr in HR. Common drug of choice for intraop HTN
Labetalol
____ is the common drug of choice for intraop HTN because decreases PVR and renin, and causes some decrease in HR.
Labetalol
The main indication for use of _____ is treatment of a thyroid storm (thyrotoxicosis) or pheochromocytomas.
Propranolol (Inderal)
Is the following a mixed, non-selective Beta, B1 selective adrenergic antagonist?
Atenolol
B1 selective antagonist
Is the following a mixed, non-selective Beta, B1 selective adrenergic antagonist?
Labetalol
Mixed antagonist (A1 B1 and B2)
Is the following a mixed, non-selective Beta, B1 selective adrenergic antagonist?
Carvedilol.
B1 selective antagonist
This non-selective beta blocker is no longer commonly used because of its following side effects: bronchospasm, CHF, bradycardia and AV heart block.
Propranolol (Inderal)
Is the following a mixed, non-selective Beta, B1 selective adrenergic antagonist?
Metoprolol
B1 selective antagonist
This adrenergic antagonist’s short duration of action is due to its rapid redistribution (2 min) and ester hydrolysis (9 min).
Esmolol (BreviBloc)
T or F. Labetalol causes reflex tachycardia.
False. It is a mixed antagonist with alpha and beta receptor antagonism.
___ is a good choice for preventing tachycardia and hypertension during intubation and emergence.
Esmolol
What are 3 side effects associated with alpha-1 receptor blockade?
Side effects: hypotension, orthostatic hypotension, tachycardia
Phenylephrine will have what effect on a patient who has taken Phenoxybenzamine?
No effect. Phenylephrine response is completely blocked
NE will have what effect on a patient who has taken Phenoxybenzamine?
Norepinephrine response: tachycardia due to B1 activation
NE will have what effect on a patient who has taken Phenoxybenzamine?
Epinephrine response: tachycardia and severe hypotension due to B2-mediated vasodilation
How does an alpha-2 receptor blockade work and what does it cause?
A2-receptor blockade -> eliminates negative feedback -> more NE release -> tachycardia
When treating a pheochromocytoma, which should you do first and which should you do second…alpha block vs beta block.
A-blockade before B-blockade
