Section 2c Adrenergic Antagonists Flashcards
2 reversible alpha antagonists
phentolamine and prazosin
an irreversible alpha antagonist
phenoxybenzamine
2 drugs that are non-selective alpha antagonists
phentolamine and phenoxybenzamine
8 drugs that are a1-selective antagonists
prazosin, terazosin, doxazosin, tamsulosin <– more important
less important = alfuzosin, indoramin, urapidil, and bunazosin
2 drugs that are a2-selective antagonists
yohimbine and mirtazapine
Will a healthy person given an alpha-adrenoceptor antagonist show effects?
not much, if at all
What is Pheochromocytoma
tumor of the adrenal medulla releasing catecholamines
If a person has Pheochromocytoma what would you recommend about phenoxybenzamine and phentolamine?
phenoxybenzamine = pre-operative period phentolamine = short-term control of HTN
What do you use to fix a-agonist problems?
Phentolamine
What are the Adverse effects of non-selective alpha antagonists?
nasal stuffiness, orthostatic hypotension, tachycardia
What would you recommend first-dose users to do with selective a1-atagonistic drugs?
The smaller dose should be taken just before bedtime to avoid postural hypotension and syncope
What could selective a1-antagonists be used for? and which one has a longer half-life?
- HTN, BPH, Raynaud’s syndrome, PTSD
2. doxazosin (22hrs)
What does Tamsulosin do?
a1A - antagonist: selective for prostate smooth muscle
What are 2 B+a-antagonistic drugs?
Labetalol (has 4 stereoisomers) and Carvedilol
What is Yohimbine used for?
orthostatic hypotension and ED
What is Mirtazapine used for?
Adverse effects?
- MDD (it can work in the CNS)
2. Adverse effects: arrhythmias (QT prolongation), drowsiness, suicide
3 drugs that are non-selective B - antagonists
propranolol (competitive), nadolol (longest 1/2 life - 12-24hrs), timolol
5 drugs that are B1 - selective antagonists
atenolol, esmolol (short 1/2 life use only IV), metoprolol, acebutolol, bisoprolol
Butoxamine is only used in research… what is its MOA?
B2 - selective antagonist
What are Beta partial agonists? (ISA - intrinsic sympathomimetic activity)
pindolol and acebutolol
What Beta antagonists are used as a local anesthetic? (membrane-stabilizing activity)
acebutolol, pindolol, and propranolol
What is the MOA for Nebivolol?
B blocker + NO production (vasodilator)
Propranolol is used to treat HTN, what 2 things could it also do that could be contradictory to health?
B2 effects: broncho-constriction & reflex peripheral vaso-constriction
What B-blockers are used for Glaucoma? (4)
timolol - topical
betaxolol, carteolol, levobunolol - oral?
What is Propranolol also used for besides BP? (3)
migraines, tremors, anxiety (stage fright)
What are other uses of Beta - antagonists in general? (4)
Ischemic heart disease (angina pectoris), cardiac arrhythmias, hyperthyroidism (thyrotoxicosis - tachycardia control), and prophylaxis of variceal (esophageal) hemorrahage [Nadolol]
What Beta - antagonists are select agents for HF?
metoprolol, bisoprolol (B1), and carvedilol (B, a1)
What drug do all Beta blockers interact with?
verapamil = hypotension, bradycardia, HF
What are possible outcomes of abrupt discontinuation of a B blocker?
high risk of cardiac ischemia and/or arrhythmias
