Adrenergic Agents Flashcards
Epinephrine (mechanism)
Stimulates a1, a2, b1, b2 (b > a)
Norepinephrine (mechanism)
Stimulates a1 > a2 > b1
Epinephrine (4 uses)
Anaphylaxis
Open angle glaucoma
Asthma
For severe hypotension
Norepinephrine (use)
For severe hypotension (but decreases renal perfusion)
Isoproterenol (mechanism)
Nonselective b-agonist
Isoproterenol (use)
For evaluation of tachyarrhythmias (specifically in hemodynamically stable TdP to increase sinus rate and shorten QT interval)
Isoproterenol (side effects)
Can precipitate tachyarrhythmias and worsen ischemia (increases risk of MI)
Dopamine (mechanism)
Stimulates D1 = D2 > b > a
Dopamine (3 uses concerning heart)
Unstable bradycardia
CHF
Cardiogenic shock
Dopamine (side effect)
Arrhythmias
Dobutamine (mechanism)
b1 agonist -> increases HR, contractility, conduction velocity, myocardial O2 consumption
Also decreases peripheral vascular resistance by having a little bit of b2 effect too
Dobutamine (2 uses)
CHF (inotropic > chronotropic)
Cardiac stress testing
Dobutamine (side effect)
Arrhythmias (b/c it increases cardiac conduction velocity)
Angina (b/c it increases myocardial O2 consumption by increasing HR and having positive inotropic effect)
Phenylephrine (mechanism)
Stimulates a1 > a2
Phenylephrine (4 uses)
Hypotension (vasopressor)
Mydriatic
Reduces secretion (so decongestant for rhinitis, hyperemia, edema)
Open obstructed eustachian tubes
Albuterol (mechanism)
Stimulates b2 > b1
Albuterol (use)
Acute asthma
“-terol” (mechanism)
Salmeterol and formoterol
Stimulates b2 > b1
“-terol” (2 uses)
Salmeterol and formoterol
Long-term asthma
Long-term COPD control
Terbutaline (mechanism)
Stimulates b2 > b1
Terbutaline (use)
Reduces premature uterine contractions
Amphetamine (mechanism)
Increases NE by being agonist, reuptake inhibitor, and causing release of stored NE
Amphetamine (3 uses)
ADHD
Obesity
Narcolepsy
Ephedrine (mechanism)
Increases NE by being agonist and causing release of stored NE
Ephedrine (3 uses)
Nasal decongestion
Urinary incontinence
Hypotension
Cocaine (mechanism)
Reuptake inhibitor of catecholamines & general agonist
Cocaine (never use with)
b-blockers if cocaine intoxication is suspected -> unopposed a1 activation -> extreme HTN
Cocaine (use)
Local anesthetic
Difference between effects of NE and isoproterenol on HR
NE has a effects whereas isoproterol doesn’t
So NE causes reflex bradycardia (a1-mediated), isoproterenol causes increased HR (b1-mediated)
Difference between effects of NE and isoproterenol on BP
NE has a effects whereas isoproterol doesn’t
So NE causes increase in BP (a1-mediated), isoproterenol causes decrease in BP (b2-mediated)
Clonidine (mechanism)
a2-agonist (sympatholytic)
Clonidine (3 uses)
HTN urgency (doesn’t decrease renal BF)
ADHD
Severe pain
Off-label for ethanol/opioid withdrawal
Clonidine (side effects)
Rebound HTN if stopped immediately
CNS & resp depression
Pro sympa stuff (bradycardia, hypotension, small pupil)
Methyldopa (mechanism)
a2-agonist (analog of L-dopa that gets converted in brain to methyl-NE)
Methyldopa (use)
HTN in pregnancy (safe to use in pregnancy)
Methyldopa (side effects)
Hemolytic anemia (direct Coombs +)
SLE-like syndrome
Hepatotoxicity
Phenoxybenzamine (mechanism)
Nonselective a-blocker (irreversible) -> dose-response curve shifted right and down (rather than just shifted right like the other REVERSIBLE a blocker) -> can look like noncompetitive binding
Phenoxybenzamine (use)
Pre-op pheochromocytoma resection (prevents catecholamines crisis)
Phenoxybenzamine (side effects)
Orthostatic hypotension, reflex tachycardia
Phentolamine (mechanism)
Nonselective competitive a-blocker (reversible)
Phentolamine (3 uses)
MAOI crisis (pts on MAOi who eat tyramine-containing foods) Cocaine overdose Pheochromocytoma
Phentolamine (side effects)
Orthostatic hypotension, reflex tachycardia
Prazosin and other “-osin” (mechanism)
a1-blocker
Prazosin and other “-osin” (use)
Urinary sx of BPH (esp tamsulosin)
Prozosin also used for PTSD
All used for HTN except tamsulosin
Prazosin and other “-osin” (side effects)
1st-dose orthostatic hypotension
dizziness, headache
Mirtazapine (mechanism)
Atypical antidepressant
a2-blocker -> increases release of NE and 5-HT
Potent 5-HT2 and 5-HT3 ANTAgonist
Mirtazapine (use)
Depression
Mirtazapine (side effects)
Sedation (desirable in depressed pts w/ insomnia tho),
Increases appetite and weight gain, increases serum cholesterol
Dry mouth
Yohimbine (mechanism)
a2-blocker
Yohimbine (historic use)
erectile dysfx (replaced by PDE inhibitors now)
B1-blockers
A-M (first half of alphabet, ending in “-olol”)
acebutolol (partial agonist), atenolol, betaxolol, esmolol, metoprolol
Nonselective b-blockers
N-Z (second half of alphabet, ending in “-olol”)
nadolol, pindolol (partial agonist), propanolol, timolol
More side effects from b2 blockade (bronchoconstriction in lungs)
Nonselective a & b blockers
Things with modified suffix
carvedilol, lavetalol
Also get decreased SVR from a blockade
Nebivolol (mechanism)
Blocks b1 (cardiac) Stimulates b3 (activates NO synthase in vasculature)
Timolol (use)
Glaucoma (reduces aq humor secretion)
Metoprolol (use)
SVT (reduces conduction velocity - class II antiarrhythmic -> prolongs PR interval)
Esmolol (use)
SVT (reduces conduction velocity - class II antiarrhythmic -> prolongs PR interval) Acute HTN emergency (ultra short acting)
B blockers (antidote)
Glucagon
B blockers (side effect)
Blunted response to hypoglycemia (dangerous in diabetics bc mask sx of hypoglycemia) -> selective B1 blockers preferable in DM over nonselective
Don’t use in suspected cocaine users (unopposed a-adrenergic activity)
Hyperkalemia w/ nonselective b blockers (interferes w/ B2 mediated intracellular K+ uptake)
Partial B agonists
Pindolol
Acebutolol
Partial B agonists (contraindication)
Angina
Metoprolol (side effect)
Dyslipidemia
Propanolol (side effect)
Exacerbate vasospasm in Prinzmetal angina
Pseudoephedrine (mechanism)
a agonist
Pseudoephedrine (3 uses)
Reduces secretions (hyperemia, edema, nasal congestion) Open obstructed eustachian tubes Illicitly used to make methamphetamine
Pseudoephedrine (2 side effects)
HTN
CNS stimulation/anxiety
Carteolol (mechanism and use)
B blocker -> decreases aq humor synthesis For glaucoma (no pupillary/vision changes)
Brimonidine (mechanism)
a2 agonist -> decreases aq humor synthesis
Brimonidine (use)
Glaucoma
Brimonidine (side effects)
Eyes stuff: blurry vision, hyperemia, foreign body sensation/pruritus, allergic rxn
Betaxolol (mechanism and use)
B blocker -> decreases aq humor synthesis For glaucoma (no pupillary/vision changes)
Propanolol (3 uses)
Essential/familial tremors
Migraine prophylaxis
Reduction of portal venous pressure (to prevent variceal bleed)
Other more obvious things