Chapter 30- Adrenergic Agonists
What is the nurse's rationale for administering clonidine to treat hypertension? A) Clonidine stimulates alpha2-receptors. B) Clonidine stimulates alpha1-receptors. C) Clonidine stimulates beta2-receptors. D) Clonidine stimulates beta1-receptors.
Ans: A Feedback: Clonidine specifically stimulates alpha2-receptors and is used to treat hypertension because its action blocks release of norepinephrine from nerve axons. Therefore, the other options are incorrect answers.
In what age group are adrenergic agonists contraindicated? A) Older adults B) Adolescents C) Children D) No age group
ANS: D Feedback: The use of adrenergic agonists varies from ophthalmic preparations for dilating pupils to systemic preparations used to support patients experiencing shock. They are used in patients of all ages. Therefore, the other options are incorrect responses.
A patient in shock is receiving an infusion of dopamine when it is discovered that an extravasation has occurred. What drug should be on standby for this occurrence? A) Phenylephrine B) Propranolol C) Phenylalanine D) Phentolamine
Ans: D Feedback: Maintain phentolamine on standby in case extravasation occurs; infiltration of the site with 10 mL of saline containing 5 to 10 mg of phentolamine is usually effective in saving the area. Phenylephrine, propranolol, and phenylalanine are not indicated for use when extravasation occurs.
The patient has been taking clonidine and is now being changed to another antihypertensive drug. How will the nurse instruct the patient regarding discontinuing the clonidine? A) "Check your blood pressure and pulse every 2 to 4 hours." B) "Inform your family the drug is being changed." C) "Reduce clonidine gradually over 2 to 4 days." D) "Keep an over-the-counter analgesic available to treat headaches."
Feedback: Do not discontinue clonidine abruptly because sudden withdrawal can result in rebound hypertension, arrhythmias, flushing, and even hypertensive encephalopathy and death; taper drug over 2 to 4 days. It is not necessary to teach the patient to check blood pressure and pulse every 2 to 4 hours, discuss plans for changing medications with the family, or prepare the patient for severe headaches.
A 4-year-old is admitted to the emergency department in shock after a motor vehicle accident. The patient weighs 12.5 kg. What would be the minimum safe dose of adrenalin if the pediatric dose is 0.005 to 0.01 mg/kg IV? A) 0.0625 mg B) 0.075 mg C) 0.08 mg D) 0.085 mg
Ans: A Feedback: To calculate the minimum dosage, multiply the child's weight in kg by the lower dosage range; 12.5 × 0.005 = 0.0625 mg.
The home health nurse is caring for a 77-year-old male patient who has just been discharged from the hospital. The patient is receiving an infusion of dobutamine (Dobutrex) to treat congestive heart failure. What is the priority nursing assessment? A) Capillary refill time and vital signs B) Effectiveness of comfort measures C) Dietary intake and hydration D) Compliance with treatment plan
Ans: A Feedback: Dobutamine, although it acts at both receptor sites, has a slight preference for beta1-receptor sites. It is used in the treatment of heart failure because it can increase myocardial contractility without much change in rate and does not increase the oxygen demand of the cardiac muscle, an advantage over all of the other sympathomimetic drugs. Assessing capillary refill time and vital signs will allow the nurse to assess perfusion as an indicator of the effectiveness of the infusing drug. Dietary intake, compliance with treatment plan, and effectiveness of comfort measures are all important assessments but the priority assessment is perfusion.
How does ephedrine act on the body? A) Stimulates the release of norepinephrine B) Acts indirectly on beta-adrenergic receptor sites C) Stimulates the release of dopamine D) Acts indirectly on alpha-adrenergic receptor sites
Ans: A Feedback: Ephedrine stimulates the release of norepinephrine from nerve endings and acts directly on adrenergic receptor sites. Therefore, the other options are incorrect.
The student nurse is administering an ophthalmic adrenergic agonist. What action would reflect the need for further education about how to administer a medication ophthalmically? A) Rests the tip of the dropper against the lower eyelid B) Grasps the lower eyelid and pulls it away to form a pocket C) Applies gentle pressure to the inside corner of the eye for 3 to 5 minutes D) Instructs the patient to close his or her eyes and look downward
Ans: A Feedback: First, wash hands thoroughly. Do not touch the dropper to the eye or to any other surfaces. Have the patient tilt his or her head back or lie down and stare upward. Gently grasp the lower eyelid and pull the eyelid away from the eyeball. Instill the prescribed number of drops into the lower conjunctival sac and then release the lid slowly (Fig. 30.1). Have the patient close the eye and look downward. Apply gentle pressure to the inside corner of the eye for 3 to 5 minutes. Do not rub the eyeball and do not rinse the dropper. If more than one type of eyedrop is being used, wait 5 minutes before administering the next one.
The nurse needs to be aware, before administering, that what drug has a duration of action of only 1 to 2 minutes? A) Isoproterenol B) Dopamine C) Phenylephrine D) Ephedrine
Ans: A Feedback: Isoproterenol has a duration of action lasting 1 to 2 minutes with immediate onset of action. Dopamine acts as long as the drug is infusing with peak action 10 minutes after initiating the infusion. Phenylephrine's duration of action is 15 to 20 minutes. Ephedrine's duration of action will depend on how the drug is administered as it could be given intramuscularly, subcutaneously, IV, or orally, but no matter by what route it is administered, the duration of action is longer than 1 to 2 minutes.
A patient is admitted to the emergency department in shock. Isoproterenol (Isuprel) is administered. What would the nurse expect the effect of the isoproterenol to be? A) Increased blood pressure B)Decreased blood pressure C)Increased body temperature D) Decreased heart rate
Ans: A Feedback: Isoproterenol stimulates beta-adrenergic receptors. Blood pressure is increased and heart rate is increased. Body temperature should not be affected.
The nurse is admitting a mental health patient and collects the medication history. The patient says he takes Haldol, midodrine, hydrochlorothiazide, acetaminophen, and Cymbalta. The nurse will call the provider to discuss what dangerous drug combination? A) Haldol and midodrine B) Hydrochlorothiazide and midodrine C) Cymbalta and midodrine D) Acetaminophen and midodrine
Ans: A Feedback: Midodrine can precipitate increased drug effects of digoxin, beta-blockers, and many antipsychotics. Such combinations should be avoided. The other drug combinations do not pose any immediate concerns.
The nursing instructor is quizzing a student who is preparing to administer an alpha-specific adrenergic agonist to a patient. The instructor asks the student what the student will assess in this patient after administering the drug. What is the student's best response? A) Blood pressure B) Respirations C) Mental status D) Vision
Ans: A Feedback: Monitor blood pressure, pulse, rhythm, and cardiac output regularly, even with ophthalmic preparations, to adjust dosage or discontinue the drug if cardiovascular effects are severe. Respirations, mental status, or vision may also need to be monitored but they are not impacted significantly by the drug being given.
The nurse is preparing discharge teaching for four patients. Which patient should be advised by the nurse that over-the-counter cold and allergy preparations contain phenylephrine and should be avoided? A)A 47-year-old woman with hypertension B)A 52-year-old man with adult onset diabetes C)A 17-year-old girl with symptoms of an upper respiratory infection D)A 62-year-old man with gout
Ans: A Feedback: Phenylephrine, a potent vasoconstrictor and alpha1-agonist with little or no effect on the heart or bronchi, is used in many combination cold and allergy products. Patients with hypertension should avoid these drugs because serious increases in blood pressure could occur. Use of this drug in patients with diabetes and gout are not contraindicated. An upper respiratory infection may be an indication for the drug.
The pharmacology instructor is discussing adrenergic agonists with the nursing class. Which drugs would the instructor tell the nursing students are generally indicated for the treatment of shock, bronchospasm, and some types of asthma? A) Sympathomimetic drugs B) Beta-blocking drugs C) Parasympathetic stimulating drugs D) Anticatecholamine drugs
Ans: A Feedback: These drugs generally are indicated for the treatment of hypotensive states or shock, bronchospasm, and some types of asthma. Beta-blocking drugs, parasympathetic stimulating drugs, and anticatecholamine drugs are not the drugs of choice in these situations.
When studying for a pharmacology exam, a student asks her peers which agents affect both alpha- and beta-receptor sites. What would be an appropriate response to this student? (Select all that apply.) A) Dobutamine (Dobutrex) B) Epinephrine (Adrenalin, Sus-Phrine) C) Dopamine (Intropin) D) Clonidine (Catapres) E) Albuterol (Proventil)
Ans: A, B, C Feedback: Agents that affect both alpha- and beta-receptor sites include dobutamine, dopamine, ephedrine, epinephrine, and norepinephrine. Clonidine is an alpha-specific adrenergic agonist; albuterol is a beta-specific adrenergic agonist.
When assessing a patient who has been prescribed midodrine, what would the nurse assess for? A) Pancreatic disease B) Renal failure C) Open-angle glaucoma D) Hypothyroidism
Ans: B Feedback: Assess for contraindications or cautions: any known allergies to the drug to avoid hypersensitivity reactions; presence of any cardiovascular diseases, which could be exacerbated by the vascular effects of these drugs; thyrotoxicosis, or diabetes, which would lead to an increase in thyroid stimulation or glucose elevation; chronic renal failure, which could be exacerbated by drug use; renal or hepatic impairment, which could interfere with drug excretion or metabolism; and current status of pregnancy and lactation. Options A, C, and D are incorrect.
The nurse is planning discharge teaching for a patient who is taking clonidine (Catapres). What would be most important for the nurse to include when teaching about adverse effects? A)Pupil constriction B)Strange dreams C)Increased urine output D)Increased appetite
Ans: B Feedback: Central nervous system effects from clonidine therapy include feelings of anxiety, restlessness, depression, fatigue, strange dreams, and personality changes. However, bad dreams would be the most upsetting and stressful effect for the patient. Pupil dilation, decreased urine output, and anorexia are all adverse effects of clonidine.
An 80-year-old patient has been brought to the emergency department in shock. The patient is receiving dopamine (Intropin). What potentially serious adverse effect will the nurse monitor for? A)Blood dyscrasia B)Cardiac arrhythmia C)Hepatic toxicity D)Renal insufficiency
Ans: B Feedback: Dopamine therapy can result in cardiac arrhythmias, which can be life threatening. Older patients are more likely to experience the adverse effects associated with adrenergic agonists and should be started on lower doses and monitored closely for arrhythmias and blood pressure changes. Blood dyscrasias, hepatic toxicity, and renal insufficiency are not commonly associated with dopamine use. In fact, at lower doses, dopamine increases renal perfusion.
A patient comes to the clinic complaining of seasonal rhinitis. What adrenergic agonist would be prescribed for treatment of seasonal rhinitis? A)Dobutamine (Dobutrex) B)Ephedrine (generic) C)Dopamine (Intropin) D)Norepinephrine (Levophed)
Ans: B Feedback: Ephedrine has been used to treat seasonal rhinitis by stimulating the release of norepinephrine from nerve endings and directly acting on adrenergic receptor sites. Although ephedrine was formerly used for situations ranging from the treatment of shock to chronic management of asthma and allergic rhinitis, its use in many areas is declining because of the availability of less toxic drugs with more predictable onset and action. Dobutamine is used to treat congestive heart failure. Dopamine and norepinephrine are used to treat shock.
The patient is taking midodrine (ProAmatine). What is the most important nursing action to include in the plan of care for this patient? A)Monitor urine output. B)Monitor blood pressure. C)Monitor heart rate. D)Monitor respirations.
Ans: B Feedback: Midodrine is an oral drug used to treat orthostatic hypotension in patients who do not respond to traditional therapy. It activates alpha-adrenergic receptors, leading to peripheral vasoconstriction and an increase in vascular tone and blood pressure. This effect can cause serious supine hypertension. Patients should be monitored in the standing, sitting, and supine positions to determine whether this will be a problem. It is also important to monitor heart rate, respirations, and urine output in this patient. However, assessing for supine hypertension would pose the greatest threat to the patient and would take priority.
The nurse is writing a plan of care for a patient receiving an alpha-specific adrenergic agonist. What should this plan of care include? A)Monitoring the patient for diarrhea B)Monitoring blood pressure and heart rate every 2 to 4 hours C)Assessing skin turgor for dehydration D)Assessing for fatigue and lethargy
Ans: B Feedback: Sympathetic stimulation will cause hypertension and increased heart rate so it is important these be monitored. Sympathetic stimulation will also result in increased sweating, decreased gastrointestinal activity, and a sense of anxiety and heightened awareness. Diarrhea, dehydration, fatigue, and lethargy would not be expected.
A 4-year-old girl is prescribed an albuterol (Proventil) inhaler for her asthma. What is the recommended safe dosage for this patient? A) 1.25 to 2.5 mg q.i.d B) 1.25 to 2.5 mg b.i.d C) 2 mg q.i.d D) 0.5 to 1 mg b.i.d
Ans: B Feedback: The recommended dosage for albuterol when given via inhaler is 1.25 to 2.5 mg b.i.d. When taken orally, the dosage is 2 mg t.i.d. or q.i.d. The other options are incorrect because they are outside the acceptable dosage range.
The nurse receives an order to begin a dopamine (Intropin) infusion at 5 mcg/kg/min. The patient weighs 50 kg. Each milliliter of solution contains 3 mg of dopamine. How many mL/h will the nurse set the pump to deliver? A) 3 mL/h B) 5 mL/h C) 3,000 mL/h D) 83.3 mL/h
Ans: B Feedback: To calculate this dosage, multiply the ordered mcg by the weight (5 ×50 kg) to yield mcg/min (250 mcg/min) and then multiply this times 60 to get mcg/h (250 ×60 = 15,000 mcg/h). Convert mcg/h to mg/h (15,000/1,000 = 15 mg/h). Set up ratio (3 mg/1 mL = 15 mg/X mL) and cross multiply (3X = 15 mg). Divide both sides by 3 to yield 5 mL/h to deliver 5 mg/kg/min.
The clinic nurse is teaching a patient about transdermal clonidine (Catapres). What information would be included in the nurse's teaching plan? (Select all that apply.) A) Change the patch in the morning. B) Rotate the site where the patch is placed. C) Monitor blood pressure daily. D) Stop the drug immediately if adverse effects occur. E) Keep the physician informed of any new diagnoses or medications.
Ans: B, C, E Feedback: Transdermal patches should not be placed in the same site repeatedly so it is important to instruct the patient to rotate sites to improve absorption of drug. Blood pressure should be monitored daily and the patient should be provided with acceptable ranges versus when to notify the physician because severe hypertension can occur. Due to drug-drug interactions, contraindications, and cautions related to specific diagnosis (cardiovascular disease, vasomotor spasm, thyrotoxicosis, diabetes, renal or hepatic impaiment), it is important for the patient to inform the physician if another physician prescribes a medication or a new diagnosis for decisions to be made about whether to continue the drug or change the dosage. The patch is changed weekly and not every morning. The patient should be taught not to stop the drug abruptly because it could lead to tachycardia, hypertension, arrhythmias, flushing, and even death.
When giving beta-specific adrenergic agonists, at what age is an adult dose given? A) 10 years B) 11 years C) 12 years D) 13 years
Ans: C Feedback: Adult doses are given to children who are 12 years and older (see dosages in Table 30.3, page 497.) Therefore, the other options are incorrect.
Isoproterenol is reserved for use in emergency situations. What is the rationale for this? A) Its onset of action B) Its duration of action C) Its adverse effects D) Its peak plasma concentration
Ans: C Feedback: Because of its many adverse effects, isoproterenol is reserved for use in emergency situations that do not respond to other, safer therapies. It is not reserved for emergency use because of its onset of action, its duration of action, or its peak plasma concentration.
What drug would the nurse expect to administer if beta-specific adrenergic agonist effects are desired to prevent bronchospasm during anesthesia? A)Dobutamine (Dobutrex) B)Ephedrine (generic) C)Isoproterenol (Isuprel) D)Phenylephrine (Neo-Synephrine)
Ans: C Feedback: Isoproterenol is a beta-specific adrenergic agonist used to prevent bronchospasm during anesthesia. Phenylephrine is an alpha-specific adrenergic agonist. Both dobutamine and ephedrine are alpha- and beta-adrenergic agonists.
The nurse calculates the infusion rate for administering dopamine to a premature infant in the neonatal intensive care unit who is in cardiogenic shock secondary to a cardiac anomaly. What is the nurse's next priority action? A) Insert an intravenous catheter B) Obtain permission from parents C) Ask another nurse to perform independent calculation D) Show the nurse's calculations to the physician
Ans: C Feedback: It is good practice to have a second person check the dosage calculation before administering the drug to avoid potential toxic effects. When having calculations double-checked, it is best to let the other person work out separate calculations rather than just looking at the nurse's calculation first because this will be more likely to catch an error. The nurse would have another nurse perform calculations rather than the doctor. Only after calculations are correct would the drug be administered, usually through a central line or the nurse may establish a peripheral line. Permission from parents is not required above general permission needed to care for the neonate.
When transcribing new orders for sympathomimetic medications prescribed for a geriatric patient, the nurse expects the dosage will be what? A) The average adult dosage B) Slightly higher than adult dosages C) The lowest possible effective dosage D) Approximately half the normal adult dosage
Ans: C Feedback: Older patients should be started on lower doses of the drugs and should be monitored very closely for potentially serious arrhythmias or blood pressure changes. Other options are incorrect.
The nurse is serving a breakfast tray to the patient receiving an alpha- and beta-adrenergic agonist medication. The nurse notifies dietary of the error with the patient's diet when finding what on the tray? A) Eggs B) Bacon C) Coffee D) Milk
Ans: C Feedback: Patients being treated with any adrenergic agonists who are also taking ma huang, guarana, or caffeine are at increased risk for overstimulation, including increased blood pressure, stroke, and death. The nurse should counsel patients to avoid these ingredients. There would be no reason to prevent the patient from ingesting eggs, bacon, or milk.
The nurse is caring for a male patient who is taking a monoamine oxidase inhibitor (MAOI). The patient complains of seasonal rhinitis and the intern for his service orders phenylephrine nasal spray. What is the nurse's priority action? A) Verify patency of the nares. B) Review the patient's medication history. C) Question the order with the prescriber. D) Position the patient to give the drug as ordered.
Ans: C Feedback: Phenylephrine, combined with MAOIs, can cause severe hypertension, headache, and hyperpyrexia. This combination should be avoided. As a result, the priority action is to remind the intern the patient is taking an MAOI and obtain an order for a different drug. Until the new order is received, no other actions would be taken.
What action do sympathomimetic drugs have in the body? A) Decreased heart rate B) Decreased blood pressure C) Increased respirations D) Increased intraocular pressure
Ans: C Feedback: Sympathomimetic drugs increase respirations. Heart rate and blood pressure are also increased and intraocular pressure is decreased.
A nurse receives an order for clonidine (Catapres) for a 25-year-old pregnant woman. What is the nurse's priority action? A)Weigh the patient to obtain correct dose/kg/day. B)Have a second nurse check the dose before administering the drug. C)Consult with the physician about the order. D)Make sure the patient is wearing a fetal monitor.
Ans: C Feedback: The nurse would consult with the physician to ensure awareness of the pregnancy and desire to administer this drug. There are no adequate studies about use during pregnancy and lactation, so use should be reserved for situations in which the benefit to the mother outweighs any potential risk to the fetus or neonate. The nurse should question the prescriber regarding this order. It would not be necessary to implement the other options.
The nursing students are studying sympathomimetic drugs. How do these drugs act on the body? A)Stimulate beta receptors and block alpha-receptors B)Stimulate alpha-receptors and block beta-receptors C)Block adrenergic receptors D)Stimulate both alpha and beta-receptors
Ans: D Feedback: Drugs that are generally sympathomimetic are called alpha-agonists (stimulate alpha-receptors) and beta-agonists (stimulate beta-receptors). These agonists stimulate all of the adrenergic receptors; that is they affect both alpha and beta-receptors.
The nurse is preparing to give isoproterenol parenterally. Before starting to administer the drug, what does the nurse ensure is on hand in case a severe reaction occurs? A) An alpha-adrenergic blocker B) An alpha-adrenergic stimulant C) A beta-adrenergic stimulant D) A beta-adrenergic blocker
Ans: D Feedback: Ensure that a beta-adrenergic blocker is readily available when giving parenteral isoproterenol in case severe reaction occurs. This makes other options incorrect.
