A nurse in a provider’s office is monitoring blood electrolytes for four clients who take digoxin.
Which of the following electrolyte values increases a client’s risk for digoxin toxicity?
Potassium 3.0 mEq/L.
Calcium 9.2 mg/dL.
Potassium 4.8 mEq/L.
Calcium 10.3 mg/dL.
The Correct Answer is A
This is because digoxin inhibits the Na-K-ATPase pump on the membrane of cardiac cells, which can cause extracellular potassium levels to rise. Hypokalemia (low potassium) caused by large dosages of diuretics may result in digoxin toxicity even at low serum digoxin levels. Digoxin toxicity can cause gastrointestinal, constitutional, and/or cardiovascular symptoms, as well as ECG changes such as signs of increased automaticity and atrioventricular node blockade.
Choice B is wrong because calcium 9.2 mg/dL is within the normal range of 8.5 to 10.5 mg/dL. Hypercalcemia (high calcium) can increase sensitivity to digoxin effects and lead to toxicity even with a lower concentration of serum digoxin, but this is not the case here.
Choice C is wrong because potassium 4.8 mEq/L is within the normal range of 3.5 to 5.0 mEq/L.
Hyperkalemia (high potassium) can also increase the risk of digoxin toxicity, but this is not the case here.
Choice D is wrong because calcium 10.3 mg/dL is within the normal range of 8.5 to 10.5 mg/dL. Hypercalcemia (high calcium) can increase sensitivity to digoxin effects and lead to toxicity even with a lower concentration of serum digoxin, but this is not the case here.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
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.
Correct Answer is C
Explanation
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.
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