Pharmacology: Alpha and Beta Blockers

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Questions and Answers

What should be monitored when a patient is taking alpha-adrenergic blockers?

Vital signs and ambulation for orthostatic hypotension (correct)

Only heart rate, without regard to blood pressure

Liver function tests only

Blood glucose levels exclusively

Which of the following medications is an alpha-adrenergic blocker?

Doxazosin (correct)

Clonidine

Benazepril

Carvedilol

What is a key precaution when administering angiotensin-converting enzyme (ACE) inhibitors?

Patients must be monitored for the development of a persistent dry cough (correct)

They should be taken with food to enhance absorption

They do not require monitoring of vital signs

They can be safely administered at any time regardless of blood pressure

How do alpha-/beta-blockers reduce blood pressure?

By blocking norepinephrine and epinephrine at their respective receptors Signup and view all the answers

What should be done if a patient's heart rate drops below 60 bpm when on alpha-adrenergic blockers?

Hold the medication Signup and view all the answers

What potential issue should be monitored in patients with diabetes taking alpha-adrenergic blockers?

Hypoglycemia Signup and view all the answers

What is a significant side effect associated with ACE inhibitors that requires monitoring?

Angioedema Signup and view all the answers

What is a common effect of adrenergic agonists such as clonidine?

Decreased heart rate and cardiac output Signup and view all the answers

What is a primary function of fibric acid agents?

Block synthesis of triglycerides Signup and view all the answers

What monitoring should be conducted for patients using nitrates?

Blood pressure for hypotension Signup and view all the answers

Which statement is true regarding SGLT2 inhibitors?

They decrease sodium and water absorption in the renal tubules Signup and view all the answers

What should patients on statins monitor for, concerning side effects?

Muscle pain or weakness Signup and view all the answers

What is the action of phosphodiesterase-3 inhibitors like milrinone?

Increase calcium availability for myocardial contraction Signup and view all the answers

What is a significant risk when using thrombolytics?

Bleeding due to clot dissolution Signup and view all the answers

What effect do vasodilators have on the cardiovascular system?

Relax smooth muscle around blood vessels Signup and view all the answers

Which of the following is important when administering sympathomimetics to older adults?

Patients require lower doses Signup and view all the answers

What is the recommended action for patients experiencing chest pain when using nitrates?

Take more medication before calling 9-1-1 Signup and view all the answers

What monitoring is crucial during intravenous administration of milrinone?

Cardiac rhythm for dysrhythmias Signup and view all the answers

What is the primary action of Angiotensin II Receptor Blockers (ARBs)?

Block the action of angiotensin II at receptors on the arteries Signup and view all the answers

Which side effect is NOT commonly associated with Angiotensin II Receptor Blockers?

Gastrointestinal bleeding Signup and view all the answers

Which drug class is used to suppress platelet aggregation?

Antiplatelet Drugs Signup and view all the answers

Which of the following medications is contraindicated in pregnancy?

Angiotensin II Receptor Blockers Signup and view all the answers

What common side effect should be monitored for in patients taking beta-adrenergic blockers?

Bronchospasm Signup and view all the answers

What is a key action of Direct Thrombin Inhibitors?

Inhibit thrombin and prevent blood clots Signup and view all the answers

Which medication class directly interferes with the synthesis of vitamin K-dependent clotting factors?

Oral Anticoagulants Signup and view all the answers

What should patients avoid while taking Calcium Channel Blockers?

Grapefruit juice Signup and view all the answers

Which symptom is a sign of potential bleeding complications in patients taking anticoagulants?

Hematomas under the skin Signup and view all the answers

Which type of medication is likely to decrease the heart rate by blocking beta receptors?

Beta-Adrenergic Blockers Signup and view all the answers

What is an essential precaution for patients taking digoxin?

Obtain daily serum potassium levels Signup and view all the answers

What common side effect is associated with bile acid sequestrants?

Bloating Signup and view all the answers

What is a primary use of Thiazide Diuretics?

Lower blood pressure and treat heart failure Signup and view all the answers

What adverse effect should be monitored for patients taking Loop Diuretics?

Dehydration Signup and view all the answers

Study Notes

Alpha-Adrenergic Blockers

Block alpha-adrenergic receptors in the heart and arterioles to decrease blood pressure
Examples: doxazosin (Cardura), prazosin (Minipress), terazosin
Monitor vital signs & hold medication if heart rate is less than 60 bpm or if BP is less than 90/60 mmHg
Use caution when ambulating due to potential orthostatic hypotension
Monitor diabetic patients for hypoglycemia

Adrenergic Agonists

Stimulate receptors in the central nervous system to decrease heart rate, cardiac output, and blood pressure
Examples: clonidine (Catapres, Duraclon), guanfacine (Tenex)
Obtain baseline vital signs, complete blood count (CBC), Coombs test, and liver function studies

Alpha-/Beta- Blockers

Block the action of norepinephrine at alpha receptors and epinephrine at beta receptors to decrease heart rate & cause vasodilation
Examples: carvedilol (Coreg), labetalol
Monitor vital signs and digoxin level when used concurrently (can increase digoxin level)
Do not discontinue abruptly
Use caution when ambulating due to potential orthostatic hypotension
Monitor diabetic patients for hypoglycemia

Angiotensin-Converting Enzyme (ACE) Inhibitors

Interfere with the enzyme that converts angiotensin I to angiotensin II, a potent natural vasoconstrictor
This results in vasodilation, decreased blood pressure, reduced afterload & improved cardiac output
Examples: benazepril (Lotensin), captopril, enalapril (Vasotec), fosinopril, lisinopril (Prinivil, Zestril), moexipril, perindopril, quinapril (Accupril), ramipril (Altace), trandolapril
Follow vital sign changes (first dose may cause severe hypotension)
Administer first dose at bedtime
Monitor BP carefully if given intravenously and with subsequent alteration in level of consciousness
Teach the patient to report the development of a persistent dry cough
Assess for angioedema, which can be life-threatening
Monitor CBC for neutropenia or agranulocytosis

Angiotensin II Receptor Blockers (ARBs)

Block the action of angiotensin II at receptors on the arteries
Examples: azilsartan (Edarbi), losartan (Cozaar), olmesartan (Benicar), valsartan (Diovan)
Monitor patient for headache, dizziness, orthostatic hypotension, rash, and diarrhea
Contraindicated in pregnancy

Anticoagulants

Inhibit thrombin and the conversion of fibrinogen to fibrin and formation of a blood clot
Assess for history of unexplained or active bleeding and laboratory results for abnormal clotting profile or evidence of active bleeding
Monitor for unusual or masked bleeding
Promptly report any evidence of bleeding such as hematemesis, hematuria, bleeding gums, or unexplained abdominal or back pain
Teach patient not to take aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), or other over-the-counter drugs without healthcare professional approval
Keep vitamin K available for patients taking warfarin to reverse effects in the event of excessive bleeding or hemorrhage

Oral Anticoagulants

Examples: warfarin (Coumadin, Jantoven)
Interfere with synthesis of vitamin K-dependent clotting factors

Direct Thrombin Inhibitors

Examples: bivalirudin (Angiomax), dabigatran (Pradaxa), desirudin
Inactivate thrombin and prevent formation of blood clots

Factor Xa Inhibitors

Examples: apixaban (Eliquis), betrixaban (Bevyxxa), edoxaban (Savaysa), rivaroxaban (Xarelto)
Inhibit factor Xa of the clotting cascade

Antidysrhythmic Drugs

Used to treat cardiac dysrhythmias
Examples: amiodarone (Nexterone, Pacerone), digoxin, diltiazem (Cardizem, Cartia), disopyramide (Norpace), propranolol (Inderal), verapamil (Calan, Verelan)
Some inhibit sodium flow into the heart muscle cell, others inhibit the flow of sodium, calcium, and potassium, others block beta receptors in the heart
This slows the rate of impulse conduction, decreases heart rate, and prolongs the refractory period
Obtain baseline data, including vital signs, cardiac rhythm (including rate, PR and QT intervals, and QRS duration), and physical assessment (especially cardiac, neurologic, and respiratory status)

### Antiplatelet Drugs

Suppress platelet aggregation and the formation of blood clots
Examples: Oral: aspirin (Bayer, St.Joseph), clopidogrel (Plavix); Intravenous: abciximab (ReoPro), eptifibatide (Integrilin), tirofiban (Aggrastat)
Report any signs of increased bruising, petechiae, or occult bleeding
Do not administer concurrently with warfarin (Coumadin)

Beta-Adrenergic Blockers

Inhibit beta-receptor stimulation in the heart, resulting in decreased heart rate and cardiac output
Examples: atenolol (Tenormin), carvedilol (Coreg), metoprolol (Lopressor, Toprol), nadolol (Corgard), propranolol (Inderal), timolol
These drugs interfere with renin release by the kidneys, decreasing the effects of angiotensin and aldosterone to decrease blood pressure
Monitor patient for bronchospasm, fatigue, sleep disturbances, nightmares, bradycardia, heart block, worsening HF, gastrointestinal (GI) disturbances, impotence, and increased triglyceride levels
Contraindicated in asthma, chronic lung disease, bradycardia, or heart block
Assess BP and apical pulse prior to administration

Bile Acid Sequestrants

Examples: cholestyramine (Questran), colesevelam (Welchol), colestipol (Colestid)
Decrease cholesterol production in the liver and bind with bile acids in the intestine to excrete cholesterol in the stool
Lower low-density lipoprotein (LDL) levels and reduce serum cholesterol
Side effects include bloating, constipation, and reduced absorption of vitamins and minerals

Calcium Channel Blockers (CCBs)

Inhibit the flow of calcium ions across the cell membrane of blood vessel and heart tissues
Less calcium allows arterial smooth muscle to relax and the arteries to dilate
Examples: amlodipine (Norvasc), diltiazem (Cardizem), nifedipine (Procardia), verapamil (Calan SR, Verelan)
Used to treat angina, dysrhythmias, and hypertension
Teach the patient to maintain a daily BP log, comply with medication regimen, avoid grapefruit juice, and monitor for tachycardia and hypotension if administered intravenously
Contraindicated in patients with third-degree block or sick sinus syndrome

Cardiac Glycoside
Example: digoxin (Digitek, Lanoxin)
Digoxin causes the heart to beat more forcefully and more slowly, improving cardiac output (positive inotropic effect)
Assess apical pulse before administering
Report signs of digitalis toxicity & monitor serum potassium
Administer with caution to older adults and those after myocardial infarction or with incomplete heart block or renal insufficiency
Follow serum drug levels to maintain therapeutic levels

Diuretics

Inhibit the reabsorption of sodium and water from the nephron tubule & promote their excretion in the urine, lowering blood pressure and treating heart failure
Examples: Loop: bumetanide (Bumex), furosemide (Lasix); Potassium-Sparing: spironolactone (Aldactone), triamterene (Dyrenium); Thiazide: chlorothiazide (Diuril), hydrochlorothiazide
Monitor serum electrolyte levels, obtain patient weight daily, teach the patient the importance of compliance with the medication regimen, assess hydration status, and monitor breath sounds for fluid volume excess

Fibric Acid Agents

Block synthesis of triglycerides in the liver to lower the serum triglyceride level
Examples: fenofibric acid (Fibricor), gemfibrozil (Lopid)
Up to 2 months of treatment may be needed to achieve a therapeutic effect

Nitrates

Potent vasodilators that dilate both arterial and venous smooth muscle
Arterial dilation improves blood flow to the heart muscle and venous dilation reduces cardiac preload to treat angina pectoris
Examples : isosorbide dinitrate (Dilatrate, Isordil), nitroglycerin (Minitran, Nitro-Bid, Nitro-Dur, Nitrolingual, NitroMist, Nitrostat)
Monitor BP frequently for hypotension
Teach the patient how to take medication for chest pain, how often it may be repeated before calling 9-1-1, and to avoid alcohol consumption (can lead to severe hypotension and cardiovascular collapse)

Phosphodiesterase-3 Inhibitors

Example: milrinone (Primacor)
Milrinone blocks the enzyme phosphodiesterase in cardiac and smooth muscle, increasing the amount of calcium available for myocardial contraction, which results in positive inotropic actions and vasodilation
Assess serum potassium levels and monitor for dysrhythmias
Monitor for ventricular dysrhythmias during IV administration

SGLT2 Inhibitors

Example: dapagliflozin (Farxiga)
Dapagliflozin decreases absorption of sodium and water from the renal tubules, which decreases blood volume and the pressure against which the heart must pump
Monitor blood pressure, pulse, and urinary output
All SGLT2 inhibitors are used to treat diabetes mellitus, including dapagliflozin

Statins (HMG-CoA Reductase Inhibitors)

Inhibit 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA), a reductase, which decreases cholesterol synthesis in the liver and lowers the level of cholesterol in the blood
Examples: atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin, pravastatin (Pravachol), rosuvastatin (Crestor), simvastatin (Zocor)
Assess triglyceride, total cholesterol, LDL, and HDL levels
Avoid use in patients who are or may become pregnant or are nursing
Monitor liver function tests & avoid use in patients with liver disease or heavy alcohol consumption
Teach the patient to avoid alcohol and assess for muscle pain, tenderness, or weakness

Sympathomimetics

Stimulate alpha- or beta-adrenergic receptors, mimicking the sympathetic nervous system
Alpha receptor stimulation produces vasoconstriction and increases the blood pressure
Beta receptor stimulation increases the rate and force of heart contractions
Examples: dopamine, dobutamine, epinephrine (Adrenalin), isoproterenol (Isuprel), norepinephrine (Levophed), phenylephrine (Vazculep)
Carefully monitor responses in older adults (may be especially sensitive to these drugs and require lower doses)
Use the intravenous route only with continuous-infusion pumps
Carefully adjust the dose to accommodate the patient's cardiovascular status

### Thrombolytics

Dissolve blood clots that have caused a myocardial infarction, pulmonary embolism, or stroke to quickly restore circulation
Examples: alteplase (Activase), reteplase (Retavase), tenecteplase (TNKase)
Must be administered within 12 hours after symptom onset (best if given within 3 hours after ischemic stroke)
Monitor carefully for bleeding
Do not administer to patients who have recently (within the past 2 weeks) fallen, been involved in a motor-vehicle crash, or experienced any form of trauma
Closely monitor cardiac rhythm because return of perfusion to the blocked vessel often results in reperfusion dysrhythmias

Vasodilators

Relax the smooth muscle around blood vessels, cause vasodilation, and decrease the blood pressure
Examples: hydralazine, minoxidil, nesiritide, nitroprusside (Nipride, Nitropress), sacubitril/valsartan (Entresto)
May produce reflex tachycardia and angina in patients with coronary artery disease
Monitor for sodium and water retention and administer IV nitroprusside cautiously for hypertensive emergency
The drugs metabolize to cyanide, so careful monitoring is required

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Description

This quiz covers the mechanisms and clinical considerations for alpha-adrenergic blockers, adrenergic agonists, and alpha/beta blockers. Test your understanding of their effects on blood pressure and heart rate, as well as important monitoring parameters. Prepare to identify key examples and understand the implications for patient care.