Pharmacology Chapter 30: Adrenergic Agonists
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 I.V?
A) 0.0625 mg
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?
B)Cardiac arrhythmia Dopamine therapy can result in cardiac arrhythmias, which can be life threatening.
A 4-year-old girl is prescribed an albuterol (Proventil) inhaler for her asthma. What is the recommended safe dosage for this patient?
B) 1.25 to 2.5 mg b.i.d 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 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?
B) 5 mL/h
When assessing a patient who has been prescribed midodrine, what would the nurse assess for?
B) Renal failure
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 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.
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 (Dobutamine, although it acts at both receptor sites, has a slight preference for beta1-receptor sites.) Dobutamine is used in the treatment of heart failure because it can increase myocardial contractility & does NOT increase the oxygen demand of the cardiac muscle. (This is an advantage over all of the other sympathomimetic drugs)
What is the nurse's rationale for administering clonidine to treat hypertension?
A) Clonidine stimulates alpha2-receptors. Clonidine specifically stimulates alpha2-receptors and is used to treat hypertension because its action blocks release of norepinephrine from nerve axons.
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) 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.
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 Midodrine can precipitate increased drug effects of digoxin, beta-blockers, and many antipsychotics. Such combinations should be avoided!
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 Isoproterenol stimulates beta-adrenergic receptors. Blood pressure is increased and heart rate is increased. Body temperature should NOT be affected.
The nurse needs to be aware, before administering, that what drug has a duration of action of only 1 to 2 minutes?
A) Isoproterenol Isoproterenol has a duration of action lasting 1 to 2 minutes with immediate onset of action.
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 (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 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.)
How does ephedrine act on the body?
A) Stimulates the release of norepinephrine Ephedrine stimulates the release of norepinephrine from nerve endings and acts directly on adrenergic receptor sites.
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 These drugs generally are indicated for the treatment of hypotensive states or shock, bronchospasm, and some types of asthma.
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 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.
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.)
B) Rotate the site where the patch is placed. C) Monitor blood pressure daily. E) Keep the physician informed of any new diagnoses or medications.
A patient comes to the clinic complaining of seasonal rhinitis. What adrenergic agonist would be prescribed for treatment of seasonal rhinitis?
B)Ephedrine (generic) Ephedrine has been used to treat seasonal rhinitis by stimulating the release of norepinephrine from nerve endings and directly acting on adrenergic receptor sites.
The patient is taking midodrine (ProAmatine). What is the most important nursing action to include in the plan of care for this patient?
B)Monitor blood pressure Midodrine is an oral drug used to treat orthostatic hypotension in patients who do not respond to traditional therapy. So, it causes vasoconstriction. (It activates alpha-adrenergic receptors, leading to peripheral vasoconstriction and an increase in vascular tone and blood pressure.)
The nurse is writing a plan of care for a patient receiving an alpha-specific adrenergic agonist. What should this plan of care include?
B)Monitoring blood pressure and heart rate every 2 to 4 hours Sympathetic stimulation will cause hypertension and increased heart rate so it is important these be monitored.
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?
B)Strange dreams Central nervous system effects from clonidine therapy include feelings of anxiety, restlessness, depression, fatigue, strange dreams, and personality changes.
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?
C) "Reduce clonidine gradually over 2 to 4 days." 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.
When giving beta-specific adrenergic agonists, at what age is an adult dose given?
C) 12 years Adult doses are given to children who are 12 years and older
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?
C) Ask another nurse to perform independent calculation
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?
C) Coffee 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.
What action do sympathomimetic drugs have in the body?
C) Increased respirations Sympathomimetic drugs increase respirations. Heart rate and blood pressure are also increased and intraocular pressure is decreased.
Isoproterenol is reserved for use in emergency situations. What is the rationale for this?
C) Its adverse effects Because of its many adverse effects, isoproterenol is reserved for use in emergency situations that do not respond to other, safer therapies.
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?!).What is the nurse's priority action?
C) Question the order with the prescriber. Phenylephrine, combined with MAOIs, can cause severe hypertension, headache, and hyperpyrexia. This combination should be avoided.
When transcribing new orders for sympathomimetic medications prescribed for a geriatric patient, the nurse expects the dosage will be what?
C) The lowest possible effective dosage
A nurse receives an order for clonidine (Catapres) for a 25-year-old pregnant woman. What is the nurse's priority action?
C)Consult with the physician about the order. The nurse would consult with the physician to ensure awareness of the pregnancy and desire to administer this drug.
What drug would the nurse expect to administer if beta-specific adrenergic agonist effects are desired to prevent bronchospasm during anesthesia?
C)Isoproterenol (Isuprel) •Isoproterenol is a beta-specific adrenergic agonist used to prevent bronchospasm during anesthesia. •Phenylephrine is an alpha-specific adrenergic agonist. •Both dobutamine + ephedrine are alpha- and beta-adrenergic agonists
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?
D) A beta-adrenergic blocker Ensure that a beta-adrenergic blocker is readily available when giving parenteral isoproterenol in case severe reaction occurs.
In what age group are adrenergic agonists contraindicated?
D) No age group The use of adrenergic agonists varies from ophthalmic preparations for dilating pupils to systemic preparations used to support patients experiencing shock.
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?
D) Phentolamine 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.
The nursing students are studying sympathomimetic drugs. How do these drugs act on the body?
D)Stimulate both alpha and beta-receptors Drugs that are generally sympathomimetic are called alpha-agonists (stimulate alpha-receptors) and beta-agonists (stimulate beta-receptors).