Pharmacology Sympathetic Antagonists MOA Flashcards
Irreversiblyblocks a1 and a2 indirect baroreflex activation
Phenoxybenzamine
Reversibly blocks a1 and a2
Phentolamine
Blocks a1, not a2
Prazosin, doxazosin, terazosin
Slightly selective for a1A
Tamsulosin
Blocks a2
Elicits inc central sympathetic activity
Inc norepinephrine release
Yohimbine
Blocks B and a1
B>a1 block
Labetalol
Block B1 and B2
Propranolol
Nadolol
Timolol
Block B1> B2
Metroprolol Atenolol Alprenolol Betaxolol Nebivolol
Lower HR and BP
Reduce renin
Safer in asthma
Block B1> B2
MAABN Metoprolol Atenolol Alprenolol Betaxolol Nebivolol
Lower HR and BP
Reduce renin
Maybe CI in asthma
Propranolol
Nadolol
Timolol
Lowers BP
HR rises due to baroreflex activation
Phenoxybenzamine
Blocks a-mediated vasoconstriction Lowers BP Inc HR (baroreflex)
Phentolamine
Alpha 1 selective used to lower BP
Prazosin
Doxazosin
Terazosin
Blockade may relax prostatic SM more than vascular SM
Tamsulosin
Lowers BP with limited HR inc
Labetalol
Used for pheochromocytoma and high catecholamine states
Phenoxybenzamine
Used for htn and BPH
Prazosin
Doxazosin
Terazosin
Used for BPH
Tamsulosin
Prazosin
Doxazosin
Terazosin
Used for male erectile dysfunction
Yohimbine
Propranolol
Nadolol
Timolol used for
Htn Angina pectoris Arrhythmias Migraine Hyperthyroidism
Metoprolol Atenolol Alprenolol Betaxolol Nevivolol used for
Angina pectoris
Hypertension
Arrhythmias
Irreversible blocker of alpha receptors
Phenoxybenzamine
Duration of effect of phenoxybenzamine
> 1 day
Adv of bradycardia
Fatigue
Vivid dreams
Cold Hands
Metoprolol Atenolol Alprenolol Betaxolol Nevivolol
Toxicity of propranolol
Nadolol
Timolol
Bradycardia Worsened asthma Fatigue Vivid dreams Cold hands
Blocks B2> B1
Butoxamine
Blocks B1B2 with intrinsic sympathomimetic (partial agonist) effect
Pindolol Acebutolol Carteolol Bopindolol Oxprenolol Celiprolol
B > a1 block
Bucindolol
B1>B2
Esmolol
Blocks tyrosine hydrolase
Reduces synthesis of dopamine, norepinephrine, epineprhine
Metyrosinase
Inc peripheral resistance
butoxamine
Very brief cardiac blockade
Esmolol
Lowers BP, modestly lowers HR
Pindolol Acebutolol Carteolol Bopindolol Oxprenolol Celiprolol Penbutolol
Lowers BP
Central nervous system may elicit extrapyramidal effects (due to low dopamine)
Metyrosine
No clinical indication
Butoxamine
Pindolol Acebutolol Carteolol Bopindolol Oxprenolol Celiprolol Penbutolol
Hypertension
Arrhythmias
Migraiine
May avoid worsening of bradycardia
Used for heart failure
Carvedilol
Medroxalol
Bucindolol
Rapid contorl of BP, arrythmias, thyrotoxicosis, myocardial ischemia intraoperatively
Esmolol
Used for pheochromocytoma
Phenoxybenzamine (block a1 and a2)
Phentolamine (block a vasoconstriction)
Metyrosine (tyrosine hydroxylase inhibitor)
Tyrosine hydroxylase inhibitor
Metyrosine
Toxicity of butoxamine
Asthma provocation
Toxicity of Pindolol Acebutolol Carteolol Bopindolol Oxprenolol Celiprolol Penbutolol
Fatigue
Vivid dreams
Cold hands
Toxicity of
Carvedilol
Medoxalol
Bucindolol
Fatigue
Toxicity of esmolol
Bradycardia, hypotension
Metyrosine toxicity
EPS, orthostatic hypotension, crystalluria