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98 Cards in this Set
- Front
- Back
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Role of B1 on the heart
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increase heart rate and contractility
= increased cardiac output "Fight or flight" response |
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Role of muscarinic on the heart
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decreased heart rate, contractility
=decreased cardiac output |
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What is a concern of beta blockers on those who exercise?
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The lack of ability to increase heart rate when exercising can be harmful to the patient. Need to assess tone and activity to deliver right amount of beta blockers
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Sympathetic receptors on the vasculature (2 major, 1 minor)
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Alpha-1 (constricts)
Alpha-2 (not significant, constricts) Beta-2 (dilation, so relaxes) *No parasympathetic innervation in the vasculature |
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Why do we not use epinephrine in settings of hemorrhage or septic shock (low BP due to infection)?
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Because it also stimulates Beta 2 receptors which will dilate the vessels and worsen the bleeding.
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Epinephrine stimulates what receptors? Effect?
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Both alpha and Beta. Increases heart rate, strength of ventricular contraction
Relaxes smooth muscle of airways, dilating the bronchioles relaxes detrusor muscle Dilates pupil |
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If BP decreases (As in orthostatic hypotension or hemorrhage) - what is the body's reaction?
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Baroreceptors decrease firing
Sympathetics increased, PS decreased B1 of heart and A1 of vessels main factors *When BP is high, we want more PS response, we increase baroreceptor firing" |
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Sympathetic NS innervates what receptor in the eye? What effect?
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Alpha 1 -Dilation via contraction of the radial muscle
Beta 2 - relax ciliary for far vision increase (Lack of sympathetics causes Miosis, as in Horners syndrome causing constriction) |
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Parasympathetic innervation of the eye?
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Acetylcholine on the muscarinic receptor constricts the eye
Also, constricts the ciliary muscle for near vision |
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Sympathetic receptors of eye intraocular pressure
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alpha 2: decreases aqueous humor production
Beta 1: Increases AH production Beta 2: increases AH production |
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Sympathetic response on the lung
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Beta 2
Relaxes smooth muscle, decreases vascular permeability in lung, inhibits release of inflammatory mediators from mast cells Increases cilial beat to remove secretions |
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PS response to the lung
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Muscarinic
Constricts smooth muscle and Increases mucous secretion (Consider blocking this in COPD patients during surgery) |
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What actions does the Sympathetic and Parasympathetic have on the urinary system?
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Sympathetic: Alpha-1-a contracts the internal sphincter to hold back urine. Beta 2 relaxes the wall of the bladder, detrusor muscle
PS: M3 contracts wall of bladder and relaxes the sphincter - to release urine |
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What is the main approach to treat BPH?
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Block alpha-1-a in the sympathetic system (Tamsulosin)
or Promote muscarinic receptors / Parasympathetic pathway to help him release urine |
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Sympathetic receptor on the liver and its effect?
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Beta 2
Glycogenolysis and gluconeogenesis *Warning for diabetics if you give them Beta agonists as it will increase their blood sugar |
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An individual with impaired Sympathetic and parasympathetics in the body can be explained by what?
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Impaired function of nicotinic cholinergic receptors
or Decreased levels of norepinephrine in the bloodstream |
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Sustained Orthostatic hypotension is a problem of what pathway?
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Impaired sympathetic
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What is sympathomimetics?
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Drugs which mimic effects of activation of the Symp NS or the transmitters release in Symp NS
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What are 3 endogenous catecholamines
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NE
DA EPI **All are mixed alpha and beta adrenergic receptor agonists. Dopamine activates dopamine receptors |
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Epinephrine stimulation
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Potently stimulates alpha and beta
-Higher affinity for beta than alpha Increases cardiac HR and contraction |
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Where is epinephrine made?
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In the adrenal medulla
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What are therapeutic uses of epinephrine?
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Bronchospasm (via B2 agonism)
Anaphylaxis - (a1, b1) Restore cardiac function in arrest Local hemostasis |
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Potential side effects of epinephrine?
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Too much B1 in heart leading to palpitations, arrythmia and even heart attack
Vascular: increased BP and possible stroke/ heart attack |
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Why is epinephrine contraindicated in patients on beta blockers?
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Then epinephrine will only target a1 and a2 receptors which would lead to vasoconstriction of vessels and the lack of b2 to dilate these vessels could cause hypertensive state
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Why is epinephrine contraindicated in diabetics?
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B2 stimulation in liver leads to gluconeogenesis/glycogenolysis which raises blood glucose levels
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Contraindications for Epinephrine
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Patients on Beta receptor agonists
patients with cerebrovascular disease Diabetics hyperthyroidism (already have increased HR and palpitations) pregnancy |
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What is the main difference between norepi and epinephrine
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Norepi has little b2 activity relative to Epi
(Norepi then is more practical at increasing peripheral resistance since there is a1 resistance but no b2 dilation in vessels) |
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Therapeutic uses of NorEpi
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Blood pressure control in acute hypotensive states (a-1, b-1)
Cardiac arrest and profound hypotension (a-1, b-1) |
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Adverse effects of Norepi
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Decreased blood flow to vital organs
bradycardia (slow, forceful heartbeat due to baroreceptor reflex), arrythmias |
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Dopamine affects on what receptors (varies by dose)?
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DA>B>A (D1 DA receptors are selected at low dose)
Increase of dose leads to B (increased HR/contractility) and then A (Vasoconstriction) |
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Contraindications of Dopamine
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Pheochromocytomas (tumors which produce NE and EPI, DA leads to more NE/EPI production)
Patients with occlusive vascular disease (a-1 stimulation exacerbates constriction) MAO inhibitors/ tricyclic antidepressants |
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Advantage of Dopamine over the other catecholamines
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Dopamine receptors maintain/increase vital organ perfusion, especially in Renal
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What are the alpha-1 agonist drugs (2)? When are they particularly used?
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Phenylephrine
Midodrine Treat hypotension, similar to norepi |
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Effects of alpha-1agonists
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Mydriasis of the eye (pupil dilation)
Increased HR Increased Mean arterial pressure (A-1 stimulation) Decrease HR (secondary effect to the increased BP) Urinary retention via a-1 sphincter muscle |
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When is midodrine used?
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Tx for orthostatic hypotension ( associated with Autonomic failure
I.e. Dysautonomia |
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Side effects of alpha - 1 agonists
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Urinary retention (a-1 acts on sphincter)
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alpha 2 agonist drug and its purpose?
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Brimonidine
Tx (topical) for glaucoma by decreasing aqueous humor production (Open-angle glaucoma / ocular hypertension) |
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Beta agonists: 1(non-selective) , 3 (B-2 selective)
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Isoproterenol (non-selective so both B-1 and B-2)
B-2Selective:Albuterol, Levalbuterol, Formoterol B-2 selective (IV) : Terbutaline |
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Use for Isoproterenol?
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(beta agonist) Few cardiac indications such as heart block. Can be used for low Cardiac output / hypotensive / shock states
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Albuterol use?
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Given nebulized in ER for acute exacerbations of asthma
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What is the benefit of Terbutaline over the other Beta agonists?
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Can be given IV (parenteral). Ideal for emergency treatment of status asthmaticus (acute exacerbation of asthma)
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Which beta agonist drug is an option for cardiac treatment?
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Isoproterenol (nonselective B1/B2)
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Formoterol, B2 agonist, has a black box warning for what?
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It has a long duration of action. So it may increase risk of asthma related death.
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Therapeutic uses of beta agonists?
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Isoproterenol for Cardiovascular
B-2 selective agonists: bronchospasms and also management in COPD for airway obstruction |
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Name (3) mixed agonists?
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Dobutamine
Ephedrine Pseudoephedrine |
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Dobutamine application?
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Cardiac decompsensation due to heart disease or cardiac surgery (failure or shock)
(B1 effects predominate over alpha) |
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Uses of Ephedrine / Pseudoephedrine
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Hypotension (ephedrine injection; a-1, b-1)
Nasal congestion (alpha-1) asthma (b-2) |
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Pharmacology of Ephedrine and pseudoephedrine
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Agonists on both a and b receptors
Indirectly releases norepi |
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Contraindication of ephedrine / pseudoephed
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MAO inhibitors
Cardiovascular disease hyperthyroidism diabetes prostatic hypertrophy (activation of a-1 on sphincter) |
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What is Fenoldopam? Use? Contraindication?
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Dopamine receptor agonist (acts on D1 receptors)
Treat hypertension, given IV, safe and effective tx for severe hypertension in hospital Contraindicated in glaucomic patients / increased ocular pressure |
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Physiological effects from Fenoldopam?
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Renal vasodilation (due to d1 activation) - relaxes vascular smooth muscle
natriuresis and diuresis (inhibits sodium reabsorption) |
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Use of Cocaine? mechanism?
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ENT surgery, local anesthetic
Blocks reuptake of catecholamines leading to increased sympathetic signaling of alpha / beta receptors |
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Methylphenidate pharm? Adverse effect?
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Blocks reuptake of catecholamines by NET and DAT.
Adverse effect: tachycardia due to b1 stimulation, along with increased BP |
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Mixed a1/a2 antagonists (2) and therapeutic use?
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Phenoxybenzamine (irreversible)
Phentolamine (reversible ) Pheochromocytomas and management of local ischemic necrosis (phentolamine) |
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Effects of mixed a1/a2 antagonists?
Adverse effects? |
Vasodilation leading to lower BP
Indirectly increases HR (reflex tachycardia) Adverse: orthostatic hypotension w/ reflex tachycardia, arrythmias ; nasal stuffiness ; GI N/V |
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Treatment of pheochromocytoma?
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Mixed a1/a2 agonists phenoxybenzamine: long term management
phentolamine: short term pre-op, peri-op management |
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Contraindications of a1/a2 antagonists?
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Coronary artery disease (MI, atherosclersos)
Admin of mixed sympathomimemtic drugs because B receptor activation will be unopposed leading to hypotensive episode w/ reflex tachycardia |
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What are the (3) a-1 adrenergic receptor antagonists?
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Doxazosin, Terazosin
Tamsulosin (alpha-1-a in bladder) |
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Therapeutic use of Doxazosin and Terazosin?
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Hypertension (mild to moderate)
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Why is Tamsulosin (Flomax) not effective tx for hypertension?
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because it is alpha -1 a selective which only affects the bladder (used to treat BPH)
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Adverse effects of alpha antagonists
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Syncope
Drowsiness or asthenia (weakness) Nasal congestion / rhinitis Retrograde ejactulation (for alpha -1a selective antagonists) |
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what is the first dose phenomenon concern w/ alpha 1 antagonists?
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Postural hypotension and dizziness or syncope that can be experienced on first dose of drug.
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Suffix for Beta antagonists
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"-olol"
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What are the 3 non-selective beta blockers (b1 and b2 antagonists) and general uses for them
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Propranolol (MI survival)
Nadolol (Long duration drug - Angina pectoris) Timolol (Glaucoma Tx, eye application) |
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Beta 1- selective Antagonists (4) and their common uses
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Metoprolol (MI, CHF)
Atenolol (Acute MI) Esmolol (Acute, short half life) Betaxolol (Tx of Glaucoma) |
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Which Beta blocker would you use in perioperative / emergency management of tachycardia or hypertension?
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Esmolol, has short half life
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In what situation would a beta blocker be practical to use for someone who exercises?
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Angina pectoris. Exercise tolerance may be improved because such patients are limited by anginal pain.
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What are the physiological effects of beta blockers?
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Decrease HR and contracility
Decreased peripheral resistance in vasculature Decreased renin release Decrease glycogenolysis and glucose mobilization Decreased aqueous humor production |
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Which beta blockers may be used for Angina pectoris (chest pain due to ischemia)?
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Nadolol
Propranolol Atenolol Metoprolol |
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Beta blockers used to treat Cardiac Arrhythmias
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Propranolol
Esmolol |
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Contraindications for Beta blockers
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Patients w/ greater than 1st degree AV block
Patients w/ sinus bradycardia Patients in cardiogenic shock / cardiac failure Caution: Diabetics, CHF, bronchospastic disorders |
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Black box warning for Beta blockers
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Immediate discontinuance of drug can cause exacerbation of angina, MI, and ventricular arrhythmias.
When planning to discontinue drug, reduce the dosage over a few weeks. |
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Mixed a-1, b antagonist
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Carvedilol (Tx hypertension and CHF)
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How does Carvedilol work to treat CHF?
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Decreases HR and contractility
Decreases chance of fatal arrhythmia Decrease effects of excessive catecholamines on myocardial cells Decrease TPR |
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What is clonidine? Use? Adverse effects?
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Alpha- 2 agonist ( Brimonidine is also a-2 agonist, but used in the eye)
Used for Hypertension Adverse: Dry mouth, sedation, hypotension/dizziness |
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Physiological effect of Clonidine?
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Get initial increase in BP due to alpha 2 receptors. This is followed by hypotensive state due to the effects of clonidine on the brain stem and decreasing sympathetic function
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How does Reserpine work? Treatment?
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Depletes Norepi stores, prevents storage of catecholamines - acts on VMAT
Tx of hypertension and symptoms in agitated psychotic states. |
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Contraindications for reserpine
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Depression, active peptic ulcer or ulcerative colitis (it increases gastric acid secretion)
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What are contraindications of cholinomimetics?
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Asthma
Coronary insufficiency Peptic ulcers (increased gastric acid) Incontinence - increase in urination |
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What is cholinomimetics?
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Increasing stimulation of cholingeric receptors (those that bind to acetylcholine)
via 1) agonist binding to receptor, a ligand binding or 2) Anticholinesterase (Anti-ChE), to decrease destruction of endogenous ligand |
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Low cardiac output or patient in Septic Shock. What is the drug of choice?
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Dopamine (B1, A1)
If patient starts coding shoot em with Epi |
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What drug do you administer to prevent local ischemic necrosis?
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Phentolamine - a-1 and a-2 antagonist
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What are the receptors that decrease aqueous humor production in eye?
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Alpha1, alpha 2
(Beta 1/2 Increases) |
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receptor that dilates vessels
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Beta 2
(balances off the constriction caused by alpha 1 when epinephrine is delivered) |
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receptors affecting secretion in the lungs
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alpha 1 decreases
B2 increases M2 M3 Increases |
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Muscle and receptor responsible for pupillary constriction
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M2,M3 on the sphincter muscle
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Receptors of the heart
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B1 (Some b2) - increases HR, contractility
M2>m3 - decrease rate, contractility, conduction velocity |
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What is renin? What receptor increase it?
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Beta 1
Renin (kidney) participates in a cascade which ultimately raises BP |
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Receptors innervating detrusor muscle and trigone/sphincter muscles
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Detrusor - Beta 2 (relaxes) ; M3 Contracts
Trigone/sphincter - a1a (contracts) ; M3 relaxes Inhibit a1a w/tamsulosin to treat BPH |
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Receptor responsible for ejaculation and sweat glands
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alpha1; (apocrine sweating)
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Receptors that create profuse, watery secretion
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M3
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Treating local ischemic necrosis
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Phentolamine (Alpha 2 antagonist)
Want to keep the vessel open and increase blood flow |
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Therapeutic use of Doxazosin and Terazosin
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Mild/moderate hypertension
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Beta antagonists used for Open Angle glaucoma
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Betaxolol (b-1)
Timolol (b-1/2) (beta receptors increase production of aqueous humor) |
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Use of clonidine
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Treat Hypertension
Has initial hypertensive response followed by prolonged hypotensive response via release of NE |
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What organs have B2 receptors? What is the purpose of these when stimulated?
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Eye (relax ciliary)
Arterioles (vasodilate) Lungs (relax) Urinary bladder (relaxes the detrusor (bladder wall)) Liver (glycogenolysis and gluconeogenesis) *Fight or flight, you need glucose, no time to pee, need to breathe, and see far* |
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What organs have B1 receptors?
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Heart
Kidney (renin) |
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Tx of pheochromocytomas?
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Phenoxybenzamine
a1/a2 antagonist |
