Chapter 31: Adrenergic Blocking Antagonists

A patient is receiving sotalol. Which instruction would be most important for the nurse to provide to the patient to ensure maximum effectiveness of the drug?

"Be sure to take the drug on an empty stomach." Sotalol absorption is decreased by the presence of food; to ensure maximum effectiveness of the drug, the patient should take it on an empty stomach, not with an antacid or after a large meal. The dose is typically divided during the day and should not be taken all at once.

A male client diagnosed with bone cancer has an order for clonidine on his chart. The nurse is concerned that this may be a mistake and asks another nurse why clonidine would be ordered for this client. What would be an appropriate response from the second nurse?

"Clonidine is sometimes prescribed for severe pain in cancer clients like this client." Clonidine is prescribed to treat severe pain in clients with cancer. Clonidine does not have an effect on cancer cells. A nurse should not blindly follow orders. Clonidine is given for hypertension, not hypotension.

A male client has been prescribed an alpha1-selective adrenergic blocking agent to treat benign prostatic hyperplasia (BPH) 2 weeks ago. Which assessment question should the nurse ask to evaluate for the expected result of this medication therapy?

"Has your urine stream improved since beginning the medication?" Alpha1-selective adrenergic blocking agents are used to treat hypertension and are often used to treat BPH because of their relaxing effects on the bladder and prostate. Reporting a better urine stream would indicate the medication therapy has achieved its therapeutic goal. None of the other options assess an expected outcome for alpha1-selective adrenergic blocking medication therapy.

The nurse is caring for a client receiving metoprolol PO. What statement should lead the nurse to believe that the client needs additional instruction?

"I can take over-the-counter cold medication, provided I don't exceed recommended doses." OTC medications can interact to increase or decrease the effects of antiadrenergic drugs. The client should monitor heart rate, and oral metoprolol should be taken with food. The client should liaise with the provider in the event of adverse effects, and the drug must not be abruptly discontinued.

A patient is to receive metoprolol. What would the nurse include in the teaching plan for this patient?

"Take this drug with food to help promote its absorption."

A female client has been diagnosed with hyperthyroidism. She asks the nurse why she is taking a medication that decreases her blood pressure like her grandmother takes. What is the nurse's best response when teaching her about the action and use of propranolol (Inderal) in the treatment of hyperthyroidism?

"The administration of propranolol will decrease your heart rate." The administration of propranolol (Inderal) to a client who has been diagnosed with hyperthyroidism will allow for decreased heart rate. It is not administered to promote bronchodilation, prevent respiratory depression, or decrease systolic blood pressure.

First-dose effect occurs when the client experiences marked hypotension and syncope with sudden loss of consciousness with the first few doses of the sympatholytic. Which intervention might be helpful for the nurse to do to decrease the risk for first-dose effect?

Administer the dose at bedtime

A nurse is caring for a patient who has been administered a centrally acting anti-adrenergic drug. The nurse knows that under which condition is the use of a centrally acting anti-adrenergic drug contraindicated?

Active hepatic disease

A nurse is caring for a patient who has been prescribed propranolol for angina. What nursing interventions should the nurse perform during ongoing assessment of the treatment?

Ask about relief of symptoms and record responses on chart. The nurse should ask about the relief of symptoms and record the responses on a chart. Determining the signs of infection in the patient is a part of the nurse's pre-administration assessment, not during ongoing assessment. The nurse need not monitor the client for a sudden decrease in urine output and a sudden increase in intraocular pressure for a client under propranolol therapy for angina.

A patient has a history of smoking. Which agent would the nurse most likely expect to be ordered?

Atenolol Atenolol is a beta-1 selective adrenergic blocker. This agent would be preferred for the patient who smokes because the drug does not usually block beta-2 receptor sites. Subsequently, it does not block the sympathetic bronchodilation that would be important for this patient. Timolol, pindolol, and nadolol are nonselective beta-adrenergic blockers that would block this sympathetic bronchodilation.

The nurse is caring for a client who suddenly stopped taking a chronically prescribed beta-adrenergic blocking drug prescribed for hypertension. The client's blood pressure (BP) ranged from 110/70 to 130/70 mm Hg and heart rate (HR) ranged 60 to 90 beats per minute while taking the drug. The nurse would predict which assessment findings to support the expected beta-adrenergic responsiveness?

BP: 200/100 mm Hg; HR 110 The beta-adrenergic blocking drug chronically blocks the beta receptors, which lead to an increase in the number of beta receptors over time. The beta receptors also become more efficient in stimulating the adenyl cyclase to activate enzymes to cause the biologic responses to epinephrine. The increased beta-adrenergic response is called up-regulation or hypersensitization, which causes the exaggerated responses when the medication was suddenly stopped by the client. The exaggerated responses include hypertension (i.e., BP 200/100) and tachycardia (i.e., HR 110) from the sudden release of catecholamine. The client would become hypotensive (i.e., BP 88/50) and bradycardic (i.e., HR 55) if the client was taking the drug regularly and needed a reduced dosage by the prescriber. A blood pressure above the client's normal range (i.e., 140/90 mm Hg and no change in the heart rate range (60-90) would not represent a client suddenly stopping the drug. The changes reflect a client taking the drug, who may need a dosage increase by the prescriber. The BP 110/70 is within range, and a HR 50-100 reflects increased variability with the heart rate but does not reflect a sudden withdrawal of the long-term treatment.

A patient with glaucoma is to receive an ophthalmic non-selective beta blocker. Which agent would the nurse expect to be prescribed?

Carteolol Carteolol is available in ophthalmic form to reduce increased intraocular pressure associated with glaucoma. Propranolol is not used to reduce intraocular pressure associated with glaucoma. Sotalol is used to treat potentially life-threatening arrhythmias and is not available in ophthalmic form. Nebivolol is used to treat hypertension and is not available in ophthalmic form.

A client has come to get lab results at the cardiology clinic. The nurse notes that the digoxin level is elevated. The nurse knows that what other medication may be responsible for the increase in digoxin level?

Carvedilol When taking both carvedilol and digoxin, the client's digoxin level becomes higher and the client is at greater risk of digoxin toxicity. Prozac, Zantac, and ampicillin do not increase a client's digoxin level.

Before discharge from the cardiac step-down (status post-MI), a client questions the prescription for beta-blockers. What should the client be told about the purpose for taking beta-blockers? (Select all that apply.)

Decrease mortality rates over several years. Protect the heart from reinfarction. After acute MI, beta blockers help protect the heart from reinfarction and decrease mortality rates over several years.

A patient is being administered nonsteroidal anti-inflammatory drugs and beta-adrenergic blocker drugs. What effect should the nurse monitor for when a patient is given both of these medications?

Decreased effect of the beta blocker

A client has been prescribed an adrenergic blocking drug for glaucoma. Which nursing interventions should the nurse include when teaching the client?

Demonstrate the technique of eye drop instillation The nurse should demonstrate the technique of eye drop installation while educating the client with glaucoma. Demonstrating the method of cleaning eyes, suggesting the client protect his eyes from exposure to sunlight, and informing the client about eye drop preservation are not related nursing interventions when teaching the client about the use of an adrenergic blocker for glaucoma.

Nonselective beta blockers are the drugs of choice for treating hypertension in patients who smoke.

False Beta-1-selective blockers, because they do not block the sympathetic bronchodilation, are the preferred drugs for treating hypertension in patients who smoke.

What would be a contraindication to the use of a non-selective adrenergic blocker?

Heart block Heart block is a contraindication to the use of a nonselective adrenergic blocker because it could be worsened by the slowed heart rate and conduction. Diabetes would require cautious use of a nonselective adrenergic blocker because the disorder could be exacerbated by the blocked sympathetic response, thus masking the usual signs and symptoms of hypo- and hyperglycemia. Bronchospasm would require cautious use of a nonselective adrenergic blocker because it could progress to respiratory distress due to the loss of norepinephrine's bronchodilating actions. Phentolamine is contraindicated in patients with myocardial infarction because of the possible exacerbation of the disease.

After reviewing information about nonselective adrenergic blockers, a group of students demonstrate a need for additional teaching when they identify what as an effect of these agents?

Increased pulse rate

Which would be most important to monitor in a patient receiving carvedilol?

Liver function studies Monitoring liver function studies would be most important because carvedilol has been associated with hepatic failure. Renal function studies may be appropriate to evaluate for possible renal dysfunction that might necessitate a change in drug dosage, but this would not be the priority. Monitoring complete blood count and coagulation studies would not be necessary.

A patient is diagnosed with a pheochromocytoma. Which medications provide adjunctive therapy in the treatment of hypertension and tachycardia?

Nonselective alpha-blocking agents Nonselective alpha-blocking drugs are used as antihypertensive drugs only when hypertension is caused by excessive catecholamines. Excessive catecholamines may result from pheochromocytoma. Diuretic agents, alpha-adrenergic stimulant agents, and cardiotonic agents are not used as adjunctive agents for pheochromocytoma.

For which category of patients should the nurse take precautions when administering anti-adrenergic drugs?

Patients with renal function impairment The nurse should take precautions with patients with renal function impairment when administering anti-adrenergic drugs. The alpha/beta-adrenergic blocking drugs should be used cautiously in patients with diabetes, chronic bronchitis, and impaired hepatic function.

A client has received a dose of dopamine intravenously. The client's IV was infiltrated, and the dopamine was injected into the subcutaneous tissues. Which medication will prevent the vasoconstriction and tissue necrosis based on this action?

Phentolamine mesylate (Regitine)

Beta-1 selective blockers have what as an effect?

Reduction in arrhythmia Beta-1 selective blockers decrease the release of renin to aid in decreasing blood pressure. Beta-1 selective blockers decrease heart rate. Beta-1 selective blockers decrease cardiac excitability and exert a membrane stabilizing effect leading to a decrease in arrhythmias. Beta-1 selective blockers decrease cardiac workload.

Which would a nurse identify as a contraindication for the use of a beta-1 selective blocker?

Sinus bradycardia

A patient has been diagnosed with benign prostatic hypertrophy and has been prescribed prazosin (Minipress) to assist in the treatment of the symptoms. How does this alpha1-blocking agent decrease urinary retention?

The medication inhibits urinary bladder contraction. Prazosin (Minipress) can be administered in multiple doses to inhibit urinary bladder contraction to decrease urinary retention. The administration of prazosin (Minipress) is not used to increase gastric motility, increase muscle contraction, or decrease blood pressure when administered for benign prostatic hypertrophy.

A patient with benign prostatic hypertrophy (BPH) has been prescribed tamsulosin. How do alpha1-adrenergic blocking agents, such as tamsulosin, assist in treating the symptoms of BPH?

They inhibit contraction of the urinary bladder.

A patient is receiving tamsulosin. The nurse understands that this drug is most likely being given for which reason?

To relax prostatic smooth muscles Tamsulosin blocks smooth muscle receptors in the prostate, prostatic capsule, prostatic urethra, and urinary bladder neck, which leads to a relaxation of the bladder and prostate and improved flow of urine in males. A decrease in vascular tone would lead to a lowering of blood pressure; tamsulosin is not used to treat hypertension. Vasodilation would lead to a lowering of blood pressure; tamsulosin is not used to treat hypertension. Tamsulosin, an alpha-1 selective blocker, does not cause the reflex tachycardia that can occur with a drop in blood pressure; tamsulosin is not indicated for the treatment of hypertension.

Which client, prescribed an adrenergic blocking agent, will require the nurse to monitor closely for adverse reactions as the dosage is titrated upward towards a therapeutic dose?

a 70 year old diagnosed with primary hypertension

The nurse is caring for several clients who are being treated with adrenergic antagonists. Which client is most likely to benefit from the administration of tamsulosin?

a 76-year-old male client with urinary hesitation and nocturia Tamsulosin is used to treat benign prostatic hyperplasia, not heart failure, glaucoma, or angina.

A 75-year-old male with no history of hypertension has been prescribed nadolol. The nurse knows that the client is likely taking the drug to treat:

angina. Nadolol is a beta blocker used in the treatment of hypertension and angina.

A patient is receiving a beta-1 selective blocker after a myocardial infarction to prevent reinfarction. The nurse understands that the rationale for using the drug would be to:

decrease cardiac workload.

A nurse is caring for a client in the critical care unit. Phentolamine (Regitine, OraVerse) has been ordered for the management of tissue necrosis caused by extravasation of parenterally administered drugs. Before administering this drug, the nurse will check the client's chart for indications of:

history of acute myocardial infarction.

A nurse is providing discharge instructions to a client who is taking atenolol for hypertension. What would the nurse teach the client regarding the possible drug interactions and what the client is advised to avoid?

ibuprofen A decreased hypertensive effect can occur if a beta selective adrenergic blocking agent is used in combination with NSAIDs. If this combination is used, the client should be monitored closely and dosage adjustments made. Antibiotics, oral contraceptives, and anti-fungal agents in combination with these drugs do not produce a decreased hypertensive effect.

Which observation might indicate that timolol is achieving the desired effect in a client?

intraocular pressure decreases Timolol is a beta blocker used for treatment of glaucoma and hypertension. Depending on the intended use, a decrease in the client's intraocular pressure or blood pressure is an indication that the drug is achieving the desired effect.

A school-age client has been admitted to the pediatric intensive care unit prior to surgery. The nurse learns that the client will likely be administered phentolamine during surgery. What is the client's most likely diagnosis?

pheochromocytoma Phentolamine is used for the prevention of severe hypertension reactions caused by manipulation of the pheochromocytoma before and during surgery. Phentolamine would not be indicated for treatment of migraine headaches, renal cell carcinoma, or heart failure.

The nurse frequently sees mature male clients with BPH seeking treatment for symptoms. After ensuring they do not test positive for prostate cancer, pharmacological intervention is one of a few treatment modalities available. Pharmacokinetics indicate alpha1-blocking agents as a treatment choice due to their:

prevention of smooth muscle contraction in nonvascular tissues.

The home care nurse is providing teaching for a client taking a nonselective beta-blocker. The nurse teaches the client the importance of notifying the prescribing health care provider when what occurs related to this medication?

pulse less than 60 beats/min on consecutive days

The nurse is providing medication education to a client prescribed an adrenergic blocker. Which nervous system is the specific focus of this classification of medications?

sympathetic Adrenergic blocking agents are also called sympatholytic drugs because they lyse, or block, the effects of the sympathetic nervous system.