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 ["B","C","D","E"]
Explanation
These are all measures that can help prevent urinary tract infection (UTI), which is an infection in any part of the urinary system, including kidneys, ureters, bladder, and urethra.
Choice A is wrong because holding the urge to urinate as much as possible can allow bacteria to grow in the bladder and cause infection.It is better to urinate frequently and completely to flush out any germs that may enter the urinary tract.
Choice B is correct because emptying the bladder before and after sexual intercourse can help remove any bacteria that may have been introduced during sex.Sexual activity is one of the common causes of UTI, especially in women.
Choice C is correct because taking antibiotics as ordered can help treat an existing UTI or prevent a recurrent one.Antibiotics are the first line of treatment for UTI and they work by killing the bacteria that cause the infection.
Choice D is correct because female patients should wipe from front to back after using the bathroom.This can prevent bacteria from the anus or fecal matter from spreading to the urethra and causing infection.
Choice E is correct because drinking 8 to 10 glasses of water a day can help dilute the urine and flush out any bacteria that may be present in the urinary tract.Water also helps maintain a healthy urinary system by keeping it hydrated and functioning well.
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
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