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48 Cards in this Set
- Front
- Back
List a REVERSIBLE (competitive) non-selective Alpha-adrenoceptor Antagonist?
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Phentol-amine
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List an IRREVERSIBLE non-selective Alpha-adrenoceptor Antagonist
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Phenoxy-benzamine
**long duration of action |
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What is the pharmacologic effect of Alpha receptor Antagonists?
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Lower the PERIPHERAL VASCULAR RESISTANCE = reduce Blood Pressure
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What can be used to "reverse" Epinephrine?
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Alpha Antagonists
-block the Alpha-1 pressor effects -do not block the Beta-2 venodilation effects = Postural Hypotension & reflex tachycardia |
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What happens when you administer Epinephrine in the presence of an Alpha Antagonist? Explain
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Tachycardia & Decreased blood pressure
-decreased Diastolic blood pressor due to Epi on Beta-2 -tachycardia is due to reflex |
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What happens when you give Phentolamine?
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Nonselective competitive Alpha antagonist
-reduces TPR & MAP -produces reflex tachycardia = SNS reflex |
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What drug is similar to Phentolamine?
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Tol-azol-ine
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What are Phentolamine and Phenoxybenzamine used for to treat?
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Pheochromocytoma = catecholamine secreting tumor
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What limits the use of both Phentolamine & Phenoxybenzamine?
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Postural hypotension & reflex tachycardia
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2 Alpha-1 Antagonists
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Pr-azosin & Ter-azosin
**1000-fold less potent at Alpha-2 |
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Alpha-1 Antagonist with a long half-life
What is it used to treat? (2) |
Dox-azosin
HTN & Urinary retention in BPH |
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2 newer Competitive Alpha-1 Antagonists that have good efficacy in treating urinary retention in BPH
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Tamsul-osin
Alfuz-osin |
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Alpha-2 selective antagonist that has no established clinical role but has been used in Erectile Dysfunction (with poor specificity)
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Yohim-bine
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What are Pheochromocytoma's?
What are the symptoms? What is used to treat it? What is rarely used to treat it? |
Tumor of the Adrenal Medulla that releases a mixture of Epinephrine & Norepinephrine
HTN, Headaches, Palpitations, Sweating Main: Phenoxybenzamine Rarely: Metyrosine = competitive inhibitor of Tyrosine hydroxylase (Tyrosine ➡ L-dopa) |
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What drugs are used in Hypertensive Emergencies?
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Direct Vasodilators = Nitrates
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Alpha Antagonists are effective in treating Chronic HTN, but may not prevent what?
What is their side effect? |
Heart Failure
Postural Hypotension |
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What is the common ending for all Beta Antagonists?
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-olol
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T or F: There are NO Beta-antagonists that are absolutely specific for Beta-1 receptors
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TRUE
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Most Beta-antagonists are well absorbed after oral administration
1. when do peak concentrations occur? 2. What is the exception drug? |
1. 1-3 hours after ingestion
2. Esmolol = rapid hydrolysis produces half-life of 10 min |
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Beta-antagonist that undergoes extensive hepatic (first-pass) metabolism
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Propanolol
-bioavailability is relative low -must be accomodated for in: parenteral administration & individual differences in metabolism |
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What effects do Beta-blockers have on the Cardiovascular system?
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1. lower Blood Pressure in patients with HTN (but doesn't cause hypotension in subjects with normal BP)
2. Negative Inotropic & Chronotropic effects 3. Slowed AV conduction; increased PR interval |
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What effect do Beta-blockers have on the Respiratory tract?
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Inhibits Bronchodilation = increases airway resistance
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What are 2 Beta-1 antagonists that can exacerbate Asthmatic attacks?
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Metoprolol
Atenolol **Beta-2's are usually the ones that cause Vasodilation but so can Beta-1's |
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What effect do Beta-blocking agents have on the Eye?
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reduce Intraocular pressure = decreased Aqueous Humor production = Glaucoma treatment
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What metabolic effects do Beta-blockers possess?
In what patients should they be used with caution? What is chronic use associated with? (2) |
Inhibit SNS stimulation of Lipolysis & Glycogenolysis (which is caused by Beta-2)
Insulin-dependent diabetics 1. increased plasma VLDL 2. decreased HDL cholesterol |
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What does “Intrinsic sympathomimetic activity” mean when referring to Beta-blockers?
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While they provide blockade of the receptor, they can retain some partial agonist activity
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What is an example of a Beta-blocker with “Intrinsic sympathomimetic activity”?
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Dichlor-iso-proter-enol
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What 3 things may Beta-blockers with Partial agonist activity prevent?
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1. precipitation of asthma
2. Bradycardia 3. Alteration of plasma lipid profile **may not be as effective as the pure antagonists in prevention of second MI |
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Prototypical nonselective Beta-blocking drug
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Pro-pran-olol
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List 6 selective Beta-1 Antagonists
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Meto-prolol
Esm-olol Aten-olol Acebut-olol Bextax-olol Biso-prolol |
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List 3 Beta-blockers with partial agonist activity (“Intrinsic sympathomimetic activity”)
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Pind-olol
Acebut-olol Carte-olol PAC partial agonist |
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2 nonselective Beta-antagonists with very long duration of action
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Nad-olol
Tim-olol |
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Reversible Alpha-1 antagonist with Nonselective Beta-blocker activity
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Labet-alol
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What happens when given Labetalol?
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Hypotension with less Tachycardia than alpha-blockers
**is an Alpha-1 blocker & nonselective Beta-blocker |
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Ultra-short-acting Beta-1 blocker with it's structure containing ester linkage
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Es-m-olol
**esterases in RBC's rapidly hydrolyze to a low affinity metabolite |
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Selective Beta-2 blocker
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Butox-amine
**has no clinical application |
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List 5 general uses of Beta-blockers
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1. HTN
2. Ischemic Heart Disease 3. Cardiac Arrhythmias 4. Glaucoma 5. Hyperthyroidism |
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What are Beta-blockers often used in combo with for treating HTN?
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Diuretic or Vasodilator drugs
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Discuss Beta-blockers and Ishcemic Heart Disease
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1. reduce the frequency of Anginal episodes
2. improve exercise tolerance 3. decrease cardiac work 4. reduce myocardial oxygen demand 5. good evidence that long-term use prolongs survival after MI |
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What types of Arrhythmias are Beta-blockers effective in treating?
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Supraventricular
Ventricular |
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What effects do Beta-blockers have that help in treatment of Arrhythmias?
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1. increase AV node refractory period
2. slows ventricular response rates in Atrial Fibrillation 3. Reduce ventricular ectopic beats |
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What type of Glaucoma are Beta-blockers used to treat?
What 2 drugs are they better tolerated than in treating this type of glaucoma? |
Open-angle Glaucoma = decreased aqueous outflow into the Canal of Schlemm
Epinephrine or Pilocarpine |
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What is the mechanism of action in which Beta-blockers treat glaucoma?
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reduce production of Aqueous Humor by the Ciliary Epithelium
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Why are Beta-blockers used to treat Hyperthyroidism?
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Many of the symptoms mimic sympathetic discharge
Beta-blockers limit excessive catecholamine activity |
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List 4 minor toxic effects of Beta-blockers
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1. Rash
2. Fever 3. Sedation 4. Depression |
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List the major adverse effects of Beta-blocker toxicity
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1. worsening of preexisting asthma
2. depression of myocardial contractility & excitability 3. Supersensitivity with abrupt discontinuation after chronic use 4. can exacerbate Hypoglycemic episodes in Diabetics |
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What could happen if you abruptly discontinue Beta-blocker use after chronic use?
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Supersensitivity could cause Hypertensive Crisis
**to prevent, gradually taper dosage |
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What are 2 Adrenergic neuron blocking drugs (get into neuron and prevent catecholamine packaging)
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Reserpine = inhibits transport of NE into vesicles
Guanadrel |