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"]
Explanation
This is a mnemonic to remember the common suffix of drugs that block the beta receptors in the heart and blood vessels, which can lower blood pressure, heart rate, and reduce chest pain. For example, metoprolol, atenolol, and propranolol are beta blockers.
Choice A is wrong because calcium channel blockers do not end in DIPINE.
Calcium channel blockers are drugs that block the entry of calcium into the cells of the heart and blood vessels, which can relax the blood vessels and lower blood pressure.
Some calcium channel blockers end in DIPINE, such as amlodipine and nifedipine, but not all of them.
For example, verapamil and diltiazem are also calcium channel blockers.
Choice C is wrong because ACE inhibitors do not end in ZoSIN.
ACE inhibitors are drugs that inhibit the enzyme angiotensin-converting enzyme (ACE), which can lower blood pressure and prevent heart failure.
ACE inhibitors usually end in PRIL, such as lisinopril, enalapril, and captopril.
Choice D is wrong because angiotensin II receptor blockers do not end in STATIN.
Angiotensin II receptor blockers are drugs that block the action of angiotensin II, a hormone that constricts blood vessels and raises blood pressure.
Angiotensin II receptor blockers usually end in SARTAN, such as losartan, valsartan, and irbesartan.
The normal range for blood pressure is less than 120/80 mmHg.
The normal range for heart rate is 60 to 100 beats per minute.
Correct Answer is C
Explanation
Urecholine is the brand name of bethanechol, a drug that belongs to the class of cholinergics, genitourinary.
Choice A is wrong because adrenergic drugs are those that activate the sympathetic nervous system, which is responsible for the fight-or-flight response.Adrenergic drugs can cause relaxation of the bladder and urinary retention, not contraction and emptying.
Choice B is wrong because anticholinergic drugs are those that block the action of acetylcholine, a neurotransmitter that mediates the parasympathetic nervous system, which is responsible for the rest-and-digest response.Anticholinergic drugs can also cause relaxation of the bladder and urinary retention, not contraction and emptying.
Choice D is wrong because adrenergic blockers are those that inhibit the action of adrenergic receptors, which are activated by adrenergic drugs or by the natural neurotransmitters norepinephrine and epinephrine.Adrenergic blockers can have various effects on the bladder depending on the type and location of the receptors they block, but they are not used to treat urinary retention.
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