Adrenergic Agonists And Antagonists Flashcards
What are the three endogenous catecholamines?
-Affect both alpha and beta receptors
Epinephrine, Norepinephrine, and Dopamine
Epinephrine has a higher affinity for
Beta receptors
The adrenergic receptor activation is dose-dependent for
Epinephrine
What are the cardiac effects of Epinephrine?
Positive inotrope and chronotrope
Causes a slight reduction in SVR which widens the pulse pressure
Epinephrine
A higher dose of epinephrine results in more
Alpha effect
The number one drug of choice for anaphylaxis (IV)
Epinephrine
Used to treat asthma (Rx bronchospasm) and open angle glaucoma
Epinephrine
Causes palpitations, HTN, tremor, and anxiety
Epinephrine toxicity
Epinephrine is contraindicated in patients on non-selective beta blockers and those with
Hyperthyroidism
Also has a dose dependent response, but has essentially no B2 activity
Norepinephrine
Has a negligible direct effect on the heart at low dose
Norepinephrine
Causes an INCREASE in both arterial and venous tone
Norepinephrine
Norepinephrine also results in an increase in
Systolic BP (SBP) and Diastolic BP (DBP)
The number one drug of choice for hypotension in sepsis and also for cardiogenic shock
Norepinephrine
Should be regarded as the first line vasopressin in the treatment of septic shock
NE
Activation of DA1 receptors in the kidney induces
Dieresis
Activation of Beta-1 receptors ion the heart produces an increase in
Contractile force
Clinically, is used for treating hypotension, low cardiac output, and unstable bradycardia
Dopamine
Dopamine toxicity causes
Arrhythmia, wide QRS, and angina
A non-selective alpha agonist
Norepinephrine
An alpha-1 selective agonist
Phenylephrine
And alpha-2 selective agonist
Clonidine
A non-selective Beta agonist
Isoproterenol
A beta-1 selective agonist
Dobutamine
A beta-2 selective agonist
Albuterol
Causes increased arterial/venous tone which results in increased BP
Phenylephrine
Causes decreased venous capacitance and a reflex decrease in HR
Phenylephrine
The number 2 drop of choice for hypotension if we can’t use NE
Phenylephrine
Has the central action of decreasing SNS outflow
Clonidine
Decreases HR and arterial/venous tone
Clonidine
Used to treat hypertension and ADHD and can be sued as an anxiolytic
Clonidine
Has the beta-1 effects of increasing HR, contractility, and conduction velocity
Isoproterenol
Has the beta-2 effects of decreasing peripheral vascular resistance (afterload)
Isoproterenol
Syncope due to slow or absent pulse
Stokes-Adams attack
Used to treat Stokes-Adams attack
Isoproterenol
Beta 1 selective adrenergic agonists
-Causes increased contractility
Dobutamine
It’s increased contractility effect is greater than its chronotropic effect
Dobutamine
The number one drug of choice for cardiogenic shock with maintained BP
Dobutamine
Add to NE in septic shock with low CO
-Used for cardiac stress test
Dobutamine
Used to treat urinary incontinence and hypotension
Ephedrine
What is the irreversible NON-selective alpha-blocker
Phenoxybenzamine
What is the reversible NON-SELECTIVE alpha blocker?
Phentolamine
Lower peripheral vascular resistance (alpha-1 block), decrease BP, and can cause orthostatic hypotension
Alpha antagonists
The ONLY irreversible non-selective alpha blocker
Phenoxybenzamine
Blocks NE reuptake at presynaptic terminals
-Alpha-1 effect is greater than alpha-2 effect
Phenoxybenzamine
Phenoxybenzamine blocks catecholamine-mediated
Vasoconstriction
Phenoxybenzamine is used to treat
Pheochromocytoma
Blocks peripheral resistance and it’s alpha-2 effects cause cardiac stimulation
Phentolamine
Used for the treatment of pheochromoytoma and in NE extravasion
Phentolamine
Used to treat a patient on MAO inhibitor w/ tyramine ingestion
Phentolamine
What is the selective alpha-2 blocker?
Yohimbine
Prazosin, terazosin, doxazosin, and tamulosin are the 4
Alpha-1 selective alpha blockers
Highly selective alpha-1 effects on relaxing arterial and venous smooth muscle
Prazosin
Used to treat hypertension and benign prostatic hyperplasia
Prazosin
Is considered “uroselective” as it blockers the alpha receptors in the prostate. Thus it is more selective for BPH
Tamulosin
Works in CNS to increase SNS outflow to periphery
- Used for erectile dysfunction
- Contraindicated in CV disease
Yohimbine
Limited bioavailability when taken orally
-Large volume of distribution
Beta-blockers
Are negative chronotropes and negative inotropes
Beta-blockers
Cause a slowed AV conduction with increased PR interval
Beta blockers
Used to treat Coronary Artery Disease (CAD)
Beta-blockers
Used to lower high blood pressure by suppressing renin release
-Only effective if you have high BP
Beta-blockers
Blockage of beta-2 receptors in the periphery can cause an increase in
Peripheral Vascular Resistance
Can cause bronchoconstriction, even w/ beta-1 selective drugs
Beta blockers
Contraindicated w/ severe obstructive disease
Beta-blockers
Block lipolysis, leading to increased VLDL and decreased HDL
-Causes impaired glucose tolerance
Beta-blockers
In the eye, beta-blockers reduce
Intraocular pressure
Used to treat a myocardial infarction
-Given in acute STEMI
Propranolol
Used in symptomatic heart failure where we see reduced ejection fraction
Metoprolol
Also used to treat hyperthyroidism, glaucoma, and migraine
Beta-blockers
Can precipitate acute MI in patients with CAD
-can cause ventricular tachyarrythmia
Beta-blockers
Can cause CHF exacerbation in patients with acute decompensated HF
Beta-blocker
The presence of an AV conduction defect can lead to a serious bradyarrhythmia when taking a
Beta Blocker
Causes bronchoconstriction, a worsens glycemic control in type 2 DM
Beta blockers
Prototypical beta blocker
-highly lipophilic
Propranolol
Has partial agonist activity and is an intrinsic sympathomimetic
Pindolol
Beta blocker with a VERY long duration of action
Nadolol
A non-selective 3rd generation Beta-blocker that has cocaine-like activity
Labetolol
alpha-1 receptor blockade leads to
Vasodilation
Also contributes to a fall in BP, in part by blocking reflex sympathetic stimulation of the heart
Beta-1 blockade
A non-selective 3rd generation beta-blocker with antioxidant and anti-inflammatory properties
Carvedilol
Beta-1(cardio)-selective antagonists are preferred in patients with asthma, COPD, and DM. Four examples are
Metoprolol, atenolol, acebutolol, and esmomlol
A ULTRA short-acting parenteral beta-1 blocker
Esmolol
A beta-1 selective third generation beta blocker
Nebivolol
Most highly selective beta-1 agent
-LONG activity
Nebivolol
Has vasodilatory effects via NO release
Nebivolol
The first line antipode to beta blocker toxicity is
Glucagon
