Digoxin (Lanoxin) is a cardiac glycoside that is among the oldest medications used for heart failure.
What are its two primary actions?
Positive chronotropy and negative inotropy.
Negative inotropy and negative chronotropy.
Positive inotropy and negative chronotropy.
Positive inotropy and positive chronotropy.
The Correct Answer is C
Digoxin is a cardiac glycoside that increases the force of heart contractions (positive inotropy) and decreases the heart rate (negative chronotropy) by inhibiting the sodium-potassium ATPase pump in the cardiac cell membranes and affecting the autonomic tone. This helps to improve the symptoms of heart failure and to control the ventricular rate in atrial fibrillation.
Choice A is wrong because positive chronotropy means increasing the heart rate, which is the opposite of what digoxin does.
Choice B is wrong because negative inotropy means decreasing the force of heart contractions, which is also the opposite of what digoxin does.
Choice D is wrong because positive inotropy and positive chronotropy would both increase the workload of the heart, which is not desirable in heart failure or atrial fibrillation.
Normal ranges for digoxin are 0.5 to 2 ng/mL for heart failure and 0.8 to 2 ng/mL for atrial fibrillation. Digoxin has a narrow therapeutic window and can cause serious side effects if overdosed or underdosed.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is A
Explanation
Digoxin is a medication that can help the heart pump more blood and slow down the heart rate in certain conditions, such as heart failure and atrial fibrillation.However, digoxin has a narrow therapeutic range, which means that too much or too little of it can be harmful.The therapeutic range of digoxin levels in the blood is 0.5-2 ng/mL, and the toxic level is >2.4 ng/mL.Digoxin should be held if the resting apical pulse of an infant is <90 bpm, an older child is <70 bpm, or an adult is <60 bpm.A pulse of 48/min in an adult is too low and could indicate digoxin toxicity, which can cause life-threatening arrhythmias. Therefore, the nurse should withhold the dose and notify the health care provider immediately.
Choice B is wrong because notifying the health care provider and monitoring the patient’s vital signs are not enough.
The nurse should also withhold the dose to prevent further exposure to digoxin.
Choice C is wrong because rechecking the pulse, making sure to count for 1 full minute, is not necessary.The nurse should already have counted the pulse for 1 full minute before administering digoxin, as per standard procedure.
Choice D is wrong because administering the dose could worsen the patient’s condition and increase the risk of digoxin toxicity and arrhythmias.
Correct Answer is D
Explanation
Alpha 1 adrenergic blocking agents have a vasodilating effect and can be used for the management of hypertension. They work by blocking the alpha 1 receptors on the vascular smooth muscle, which normally cause vasoconstriction when stimulated by catecholamines like epinephrine and norepinephrine.By preventing this constriction, alpha 1 blockers lower the peripheral resistance and blood pressure
Choice A is wrong because alpha 3 adrenergic blockers do not exist.There are only two types of alpha receptors: alpha 1 and alpha 2
Choice B is wrong because alpha 2 adrenergic antagonists do not have a vasodilating effect.
They block the alpha 2 receptors, which are located presynaptically on the sympathetic nerve terminals and postsynaptically on some vascular smooth muscle cells.Alpha 2 receptors inhibit the release of norepinephrine when activated, so blocking them would increase the sympathetic activity and vasoconstriction
Choice C is wrong because alpha 1 adrenergic agonists do not have a vasodilating effect.
They stimulate the alpha 1 receptors, which cause vasoconstriction and increase the blood pressure.Alpha 1 agonists are used to treat hypotension and nasal congestion
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today