Adrenoreceptor Agonists And Antagonists Flashcards
Drugs that mimic epinephrine and norepinephrine
Sympathomimetic drugs
Adrenergic agonists
Direct-acting (selective, non-selective), mixed-acting, indirect-acting (releasing agents, uptake inhibitor, MAO/COMT inhibitors)
Direct-acting selective agonists (alpha OR beta)
a1-phenylephrine, midorine
a2-clonidine, methyldopa
b1-dobutamine
b2-terbutaline
PCDT
PMCMDTl
Direct-acting non-selective agonists (alpha AND beta)
a1 a2-oxymetazoline
b1 b2-isoproterenol
a1 a2 b1 b2-epinephrine
a1 a2 b1-norepinephrine
OIEN
Mixed-acting agonist
Ephedrine
Indirect-acting releasing agonists
Amphetamine
Tyramine
-amine
Methylphenidate
Modafinil
Ms
Indirect-acting uptake inhibitor agonist
Cocaine
Indirect-acting MAO/COMT inhibitor agonists
Pargyline
Entacapone
PE
Drug of choice for anaphylaxis
Epinephrine
b1 - vasoconstriction and cardiac stimulant; increase in SBP due to inotropism, chronotropism
b2 - vasodilation in skeletal muscles to increase blood flow
Deficient in Parkinson’s disease
Dopamine
Regulates Na excretion, renal function
Reward stimulus relevant to addiction
Target for antipsychotic drugs
Norepinephrine drug
Levarterenol
Increase in peripheral resistance, SBP, DBP
Inotropism, chronotropism
Direct-acting selective alpha 1 agonist for mydriasis and decongestion
Phenylephrine
Increase BP
Direct-acting selective alpha 1 agonist for orthostatic hypotension
Midorine
Direct-acting selective alpha 2 agonist/s for hypertension
Clonidine
Methyldopa
Lowers BP through CNS effects which decrease sympathetic tone
A/E: sedation
*Remember PCDT
Direct-acting non-selective agonist for decongestion (topical)
Oxymetazoline (a1 a2)
Newer drug for sedation in the ICU
A/E: hypotension (central clonidine-like effect)
*Remember OIEN
Direct-acting non-selective agonist for vasodilation
Isoproterenol (b1 b2)
Inotropism, chronotropism
*Remember OIEN
Direct-acting selective beta 1 agonist of choice for cardiogenic shock
Dobutamine
Resembles dopamine
Inotropism
*Remember PCDT
Direct-acting selective beta 2 agonist for asthma and suppression of premature labor
Terbutaline
*Remember PCDT
Mixed-acting agonist that can cross the BBB and is centrally-acting
Ephedrine
Increased bioavailability and longer duration
Indirect-acting releasing agonist for mood stimulation, alertness, and appetite suppression
Amphetamine (I’m wide awake and not hungry)
Mediated through release of NE
Indirect-acting releasing agonist for ADHD
Methylphenidate
Indirect-acting releasing agonist for increased wakefulness in narcolepsy
Modafinil
Indirect-acting releasing agonist that is metabolized by MAO
Tyramine
Increased hepatic first pass = decreased bioavailability
Indirect-acting catecholamine-reuptake inhibitor agonist for ADHD
Atomoxetine
Selective inhibition of NE receptor transporter
AA
Indirect-acting catecholamine-reuptake inhibitor agonist for depression
Duloxetine
DD
Dopamine agonist for Parkinson’s disease and prolactinemia
Levodopa
Dopamine agonist for hypertension (IV)
Fenoldopam (d1)
Selective peripheral vasodilation
Chronic orthostatic hypotension - agonist
Midorine (a1)
Cardia arrest - agonist
Epinephrine (a1 a2 b1 b2)
Cardiac stress test - agonist
Dobutamine (b1)
Local vasoconstriction - agonist
Epinephrine (a1 a2 b1 b2)
Asthma - agonist
Terbutaline (b2)
Albuterol
Metaproterenol
COPD - agonist
Long-acting b2 agonists or LABAs
Formoterol
Salmeterol
Bambuterol
-terols
Mydriasis - agonist
Phenylephrine (a1)
Glaucoma - agonist
Apraclonidine (has clonidine in its name so it’s a2)
Brimonidine
Suppresses premature labor - agonist
Terbutaline (b2)
Ritodrine
Narcolepsy - agonist
Modafinil (indirect releasing)
ADHD - agonist
Methylphenidate (indirect releasing)
Clonidine (a2)
Guanfacine
Sedation - agonist
Dexmedetomidine (a2, like Clonidine, Methyldopa)
Alpha receptor reversible antagonists
Phentolamine
Prazosin
Do dissociate
Can be overcome with high concentrations
Decrease peripheral vascular resistance and BP
Prevent pressor effects
Cause orthostatic hypotension and reflex tachycardia
Miosis
Nasal stuffiness
Treatment of urinary retention (BPH)
Alpha receptor irreversible antagonist
Phenoxybenzamine
Does not dissociate
Cannot be overcome with high concentrations
Decrease peripheral vascular resistance and BP
Prevent pressor effects
Cause orthostatic hypotension and reflex tachycardia
Miosis
Nasal stuffiness
Treatment of urinary retention (BPH)
Treatment for hypertension, angina, chronic heart failure, after myocardial infarction - antagonist
Beta receptor antagonists
Lowers BP
Acute - increase in peripheral resistance
Chronic - decrease in peripheral resistance (works like an agonist)
Treatment for glaucoma (reduce IOP due to decreased aqueous humor production) - antagonist
Beta receptor antagonists
Selective alpha 1 antagonist
Prazosin - prototype?
Terazosin
Doxazosin
Tamsulosin
-osin
Selective alpha 2 antagonist
Yohimbine - prototype
Nonselective reversible alpha antagonist
Phentolamine
Phentolamine is shorter than Phenoxybenzamine
Reversible is shorter than irreversible
Nonselective irreversible alpha antagonist
Phenoxybenzamine
Phenoxybenzamine is longer than Phentolamine
Irreversible is longer than reversible
Pheochromocytoma (nonselective, irreversible antagonist)
Phenoxybenzamine
Inhibits reuptake of released NE
Blocks histamine, acetylcholine, serotonin, alpha receptors
Vasodilation
A/E: orthostatic hypotension, tachycardia, nasal stuffiness, inhibition of ejaculation
PhePhe
Pheochromocytoma (nonselective, reversible antagonist)
Phentolamine
Lowers peripheral resistance
Presynaptic a2 blockade -> cardiac stimulation
A/E: severe tachycardia, arrhythmias, myocardial ischemia
PhePhe
Hypertension (selective alpha 1 antagonist)
Prazosin
Relative absence of tachycardia
Relaxes both arterial and venous smooth muscles and smooth muscles in the prostate
Half-life: 3 hours
Terazosin
Urinary retention symptom treatment (BPH)
Half-life: 9-12 hours
Doxazosin
BPH treatment
Half-life: 22 hours
Greater potency in inhibiting contraction in prostate smooth muscles (relaxation) - antagonist
Tamsulosin
High bioavailability
Half-life: 9-15 hours
Increased risk for intraoperative floppy iris syndrome (IFIS)
Male erectile dysfunction and orthostatic hypotension - antagonist
Yohimbine
Promotes increased NE release (CNS and periphery)
Reverses antihypertensive effect of Clonidine
Hypertensive emergencies - antagonist
Labetalol
Peripheral vascular disease - antagonist
Prazosin
Phenoxybenzamine
PP
Urinary obstruction - antagonist
Prazosin
Doxazosin
Terazosin
PDT
Erectile dysfunction - antagonist
Yohimbine
Selective beta 2 antagonist
Butoxamine
Selective beta 1 antagonists
Betaxolol, Bisoprolol Esmolol Atenolol* Metoprolol Nebivolol Celliprolol
BEAM NC (nice)
Nonselective beta antagonists
Nadolol
Sotalol
Timolol
Propanolol - prototype
NSTP
Most highly selective beta 1 antagonist / most cardioselective
Nebivolol (third generation blocker)
Vasodilation
Increase insulin sensitivity
Nonselective beta antagonist with ocular hypotensive effects
Timolol
Selective beta 1 antagonist for glaucoma (topical)
Betaxolol
Reversible beta antagonist
Labetolol
Induced hypotension with less tachycardia
Nonselective beta antagonist for chronic heart failure
Carvidelol
Half-life: 6-8 hours
Ultra short-acting selective beta 1 antagonist for supraventricular arrhythmias
Esmolol
Half-life: 10 minutes
Ischemic heart disease - antagonist
Timolol
Metoprolol
Propanolol
TMP (timp)
Cardiac arrhythmias - antagonist
Esmolol
Sotalol
ES
Heart failure - antagonist
Carvidelol
Metoprolol
Bisoprolol
CMB (comb)
Glaucoma - antagonist
Timolol
Metipranolol
Betaxolol
Levobunolol
TMBL (timble)
Hyperthyroidism - antagonist
Propanolol
Migraine - antagonist
Propanolol Atenolol Timolol Metoprolol Nadolol
PAT MN (pat men)
Performance anxiety and alcohol withdrawal - antagonist
Propanolol
Major common cardiac A/E for antagonists
Bradycardia
