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Week 8 Sherpath – Unclassified Antidysrhythmic Drugs
(Adenosine, Magnesium Sulfate, Digoxin) | NCLEX-Style
Questions with Answers & Rationales | A-Graded
Nursing Pharmacology Review
The nurse is preparing to administer a loading dose of digoxin to a patient in atrial fibrillation with a heart rate of 130 beats/minute. Which statement describes the rationale for the loading dose? A. Reduce the half-life of digoxin. B. Increase the duration of digoxin action. C. Increase the peak level of digoxin.
D. Achieve therapeutic effect of digoxin more quickly. ✔✔✔answer✔✔✔D.
Achieve therapeutic effect of digoxin more quickly. A loading dose allows the therapeutic level of digoxin to be achieved more quickly. This dose is called "digitalizing." A nurse would anticipate that which dysrhythmia will likely develop when adenosine is administered? A. Paroxysmal supraventricular tachycardia (PSVT) B. Asystole C. Premature ventricular contractions (PVCs)
D. Atrial fibrillation ✔✔✔answer✔✔✔B. Asystole
The nurse would anticipate asystole when administering adenosine. Asystole is rarely sustained and is resolved quickly. A patient remains in supraventricular tachycardia after administration of adenosine 6 mg. Which action would the nurse anticipate taking? A. Prepare to administer adenosine 12 mg in 5 minutes after the previous dose. B. Give adenosine 6 mg in 1 to 2 minutes after the previous dose.
C. Start adenosine continuous infusion at 12 mg/minute. D. Administer adenosine 12 mg in 1 to 2 minutes after the previous dose.
✔✔✔answer✔✔✔D. Administer adenosine 12 mg in 1 to 2 minutes after the
previous dose. If the patient is does not respond to the first dose of adenosine within 1 to 2 minutes, then the nurse would prepare to administer adenosine 12 mg. A patient is being treated with digoxin for atrial fibrillation. Which finding would concern the nurse? A. Decrease of heart rate to 78 beats/min B. A blood pressure of 130/74 mm Hg C. Development of second-degree block D. Evidence of occasional premature ventricular contractions (PVCs)
✔✔✔answer✔✔✔C. Development of second-degree block
Digoxin prolongs the PR interval as a result of the slowed atrioventricular (AV) conduction. Development of second-degree block is a contraindication for digoxin. A nurse is reviewing laboratory results on a patient who is taking oral digoxin. Which electrolyte imbalance would the nurse associate with digoxin toxicity? A. Hyponatremia B. Hypochloremia C. Hypophosphatemia
D. Hypokalemia ✔✔✔answer✔✔✔D. Hypokalemia
Hypokalemia enhances the risk of cardiotoxicity caused by digoxin. A patient's rhythm is now asystole after receiving adenosine. Which action would the nurse take? A. Start cardiac compression. B. Defibrillate with 360 joules. C. Monitor the patient.
D. Administer potassium. ✔✔✔answer✔✔✔C. Monitor the patient.
A. Administer over 1 – 2 minutes with slow IV push B. Administer via deep IM injection C. Flush immediately with saline and monitor ECG D. Keep the patient in a semi- Fowler’s position
✔✔✔answer✔✔✔ C
Rationale: Adenosine must be given rapid IV push, immediately followed by a saline flush, while continuously monitoring the ECG due to risk of asystole or bradycardia.
- A patient receiving adenosine briefly goes into asystole. What is the appropriate nursing response? A. Start CPR B. Administer atropine C. Continue to monitor — this is an expected transient effect D. Notify the rapid response team
✔✔✔answer✔✔✔ C
Rationale: Transient asystole is a normal effect of adenosine due to AV node blockade. The rhythm usually restores spontaneously.
- What is the role of magnesium sulfate in managing dysrhythmias? A. Converts atrial fibrillation to sinus rhythm B. Terminates ventricular asystole C. Prevents torsades de pointes in patients with prolonged QT D. Increases myocardial oxygen demand
✔✔✔answer✔✔✔ C
Rationale: Magnesium sulfate is used in torsades de pointes, especially when linked to hypomagnesemia or drug-induced QT prolongation.
- Which patient would most benefit from IV magnesium sulfate administration? A. A patient in atrial flutter B. A patient with ventricular fibrillation C. A patient with torsades de pointes and low serum magnesium D. A patient with third-degree AV block
✔✔✔answer✔✔✔ C
Rationale: Torsades de pointes is a form of polymorphic VT often caused by low magnesium. IV magnesium is the first-line treatment.
- Which nursing intervention is most important before giving digoxin for dysrhythmia? A. Check oxygen saturation B. Assess lung sounds C. Measure apical pulse for 1 full minute D. Review dietary sodium intake
✔✔✔answer✔✔✔ C
Rationale: The apical pulse must be assessed before giving digoxin. Hold the dose and notify the provider if HR < 60 bpm in adults.
- A patient taking digoxin reports nausea, blurred vision, and seeing halos. What should the nurse do first? A. Encourage rest and fluids B. Give antiemetics and recheck in 1 hour C. Withhold digoxin and notify the provider D. Reassure that these are normal side effects
✔✔✔answer✔✔✔ C
Rationale: These are signs of digoxin toxicity and require immediate assessment, including checking serum digoxin levels.
- What electrolyte imbalance increases the risk of digoxin toxicity? A. Hyperkalemia B. Hypokalemia C. Hypermagnesemia D. Hyponatremia
✔✔✔answer✔✔✔ B
Rationale: Low potassium levels increase myocardial sensitivity to digoxin, leading to a greater risk of toxicity.
- Which ECG change is a red flag for digoxin toxicity? A. Widened QRS complex B. Prolonged QT interval C. ST-segment depression and bradycardia D. Peaked T waves
✔✔✔answer✔✔✔ C
Rationale: Digoxin toxicity often shows bradycardia and down-sloping ST depression, sometimes referred to as a “ scooped ST segment .”
A. Positive inotropic B. Positive chronotropic C. Negative dromotropic D. Increases conductivity E. Negative chronotropic
F. Positive dromotropic ✔✔✔answer✔✔✔A, C and E
Positive inotropic Digoxin increases myocardial contractility, a positive inotropic effect, without increasing oxygen demand. Negative dromotropic Digoxin reduces the conductivity of the heart, which is a negative dromotropic effect. Negative chronotropic Digoxin decreases heart rate, which is a negative chronotropic effect. The nurse will anticipate administering a second dose of adenosine shortly after the first dose because the drug is effective for which time frame? A. Less than 10 seconds B. 30 seconds C. 1 minute
D. 2 minutes ✔✔✔answer✔✔✔A. Less than 10 seconds
The duration of adenosine is less than 10 seconds. Frequently a second dose of adenosine is required to convert the paroxysmal supraventricular tachycardia into sinus rhythm. The nurse monitors the electrical activities of the heart while administering intravenous digoxin because of which potential effects to the heart? Select all that apply. A. Shortening of QR intervals
B. Depression of ST segments C. Shortening of PR intervals D. Increase in atrioventricular (AV) conductions E. Inversion of T waves
F. Widening of QRS complexes ✔✔✔answer✔✔✔A, B and E
Shortening of QR intervals Digoxin can shorten QR intervals due to accelerated repolarizations of the AV node. Depression of ST segments Digoxin can cause ST segment depressions. Inversion of T waves Digoxin can cause T-wave inversions. Which statement by Mr. Torres indicates an understanding of the possible side effects of adenosine? A. "I will feel the need to urinate." B. "I might feel some chest pressure, but it will not last long." C. "I will need to be on medicines for atrial fibrillation."
D. "I need to be shocked after the medicine is given to me." ✔✔✔answer✔✔✔"I
might feel some chest pressure, but it will not last long." The patient might experience brief chest pressure with adenosine. Other symptoms the patient may feel include nausea, lightheadedness, head or neck pain, or shortness of breath because of the brief periods of asystole. Because the half-life is less than 10 seconds, these symptoms should resolve quickly. Which parameter would the nurse follow when administering adenosine to a patient to treat supraventricular tachycardia? A. Undiluted and rapidly over 1 to 2 seconds as close to the heart as possible B. Undiluted and slowly in the antecubital fossa C. Diluted and rapidly in 5 mL normal saline as close to the heart as possible
E. Ginseng
F. Bran ✔✔✔answer✔✔✔A, C and E
Quinidine Quinidine can increase digoxin to a toxic level. Digoxin dose may need to be reduced by 50%.. Dronedarone Dronedarone can increase the risk of digoxin toxicity. The dose of digoxin may need to be reduced. Ginseng Ginseng can increase the risk of digoxin toxicity. Avoid ginseng. Digoxin is prescribed to a patient who has been taking verapamil for hypertension. Which dosing change would the nurse anticipate seeing in the prescription? A. An increase in digoxin dose by 50% B. A reduction in digoxin dose by 50% C. A decrease in verapamil dose by 50%
D. An increase in verapamil dose by 50% ✔✔✔answer✔✔✔B. A reduction in
digoxin dose by 50% Verapamil decreases digoxin clearance, thereby increasing the effects of digoxin. The dose of digoxin should be decreased by 50%. Before administering digoxin, the nurse would conduct a thorough assessment, knowing that digoxin accumulates the highest in which areas of the body? Select all that apply. A. Kidney B. Brain C. Intestine D. Skin
E. Heart
F. Skeletal muscle ✔✔✔answer✔✔✔A, C , E and F
Kidney Digoxin accumulates mostly in the heart, kidneys, intestine, liver, stomach, and skeletal muscle. Intestine Digoxin accumulates mostly in the heart, kidneys, intestine, liver, stomach, and skeletal muscle. Heart Digoxin accumulates mostly in the heart, kidneys, intestine, liver, stomach, and skeletal muscle. Skeletal muscle Digoxin accumulates mostly in the heart, kidneys, intestine, liver, stomach, and skeletal muscle. A nurse is preparing to administer adenosine through an established intravenous site with intravenous fluids infusing. Which intravenous fluids would the nurse accept as compatible with adenosine? Select all that apply. A. D10W B. 0.9% NaCl C. D5W D. Theophylline drip
E. Ringer's lactate ✔✔✔answer✔✔✔B, C and E
0.9% NaCl 0.9% NaCl (normal saline) is compatible with adenosine.
