Antidysrhythmic Drugs Flashcards
The nurse is reviewing the classes of antidysrhythmic drugs. Amiodarone is classified on the Vaughan Williams classification as a class III drug, which means it works by which mechanism of action?
a. Blocking slow calcium channels
b. Prolonging action potential duration
c. Blocking sodium channels and affecting phase 0
d. Decreasing spontaneous depolarization and affecting phase 4
ANS: B
Vaughan Williams class III drugs (amiodarone, dronedarone, sotalol, ibutilide, and dofetilide) increase the action potential duration by prolonging repolarization in phase 3. The other answers are incorrect.
A patient is taking procainamide for a cardiac dysrhythmia. The nurse will monitor the patient for which possible adverse effect?
a. Bradycardia
b. Shortened QT interval
c. Dyspnea
d. Diarrhea
ANS: D
Diarrhea is a potential adverse effect of procainamide therapy. Prolonged QT interval on the ECG is also possible. The other options are incorrect.
The nurse will monitor the patient who has been taking dronedarone for which adverse effect?
a. Decreased white blood cell count
b. Liver toxicity
c. Dehydration
d. Peripheral edema
ANS: B
The FDA has issued an advisory regarding the potential for hepatotoxicity related to dronedarone therapy. The other options are incorrect.
A patient will be discharged on quinidine sulfate extended-release tablets for the treatment of ventricular ectopy. The nurse will include which information in the teaching plan?
a. The medication should be stopped once the cardiac symptoms subside.
b. Signs of cinchonism, such as tinnitus, loss of hearing, or slight blurring of vision, may occur.
c. It is important to use sunscreen products when outside because of increased photosensitivity.
d. If any tablet or capsule is visible in the stool, contact the prescriber immediately.
ANS: B
Quinidine may cause the symptoms of cinchonism, including tinnitus, loss of hearing, slight blurring of vision, and gastrointestinal upset. The medication will need to be continued even after cardiac symptoms subside, or the symptoms may return. Tablets or capsules that are visible in the stool are actually the wax matrices that contained the drug; the medication is extracted while in the intestines. Photosensitivity occurs with class III drugs, not with quinidine (class Ia).
A patient is in the intensive care unit because of an acute myocardial infarction. He is experiencing severe ventricular dysrhythmias. The nurse will prepare to give which drug of choice for this dysrhythmia?
a. Diltiazem
b. Verapamil
c. Amiodarone
d. Adenosine
ANS: C
Amiodarone (Cordarone) is the drug of choice for ventricular dysrhythmias according to the Advanced Cardiac Life Support guidelines. The other drugs are not used for acute ventricular dysrhythmias.
The nurse is preparing to administer adenosine to a patient who is experiencing an acute episode of paroxysmal supraventricular tachycardia. When giving this medication, which is important to remember?
a. The onset of action occurs within 5 minutes.
b. The medication must be given as a slow intravenous (IV) push.
c. Asystole may occur for a few seconds after administration.
d. The medication has a long half-life, and therefore duration of action is very long.
ANS: C
Adenosine has an extremely short half-life of less than 10 seconds; its onset occurs within 1 minute; and it must be given as a fast IV push injection. In addition, a very brief episode of asystole may occur after administration.
A 62-year-old man is to receive lidocaine as treatment for a symptomatic dysrhythmia. Upon assessment, the nurse notes that he has a history of alcoholism and has late-stage liver failure. The nurse will expect which adjustments to his drug therapy?
a. The dosage will be reduced by 50%.
b. A diuretic will be added to the lidocaine.
c. The lidocaine will be changed to an oral dosage form.
d. An increased dosage of lidocaine will be prescribed so as to obtain adequate blood levels.
ANS: A
Because lidocaine is metabolized primarily by the liver, a reduction of the dosage by 50% may be necessary in cases of liver failure or cirrhosis. Lidocaine does not come in oral form.
When starting a patient on antidysrhythmic therapy, the nurse will remember that which
problem is a potential adverse effect of any antidysrhythmic drug?
a. Deficiency of fat-soluble vitamins
b. Hyperkalemia
c. Heart failure
d. Dysrhythmias
ANS: D
Many antidysrhythmics are themselves capable of producing new dysrhythmias (the
prodysrhythmic effect). The other options are not adverse effects of antidysrhythmic drugs.
A patient has been started on therapy of a continuous infusion of lidocaine after receiving a loading dose of the drug. The nurse will monitor the patient for which adverse effect?
a. Drowsiness
b. Nystagmus
c. Dry mouth
d. Convulsions
ANS: D
Convulsions are possible if lidocaine reaches toxic levels. The other options are not adverse effects of lidocaine.
A patient is in the emergency department with a new onset of rapid-rate atrial fibrillation, and the nurse is preparing a continuous infusion. Which drug is most appropriate for this dysrhythmia?
a. Diltiazem
b. Atenolol
c. Lidocaine
d. Adenosine
ANS: A
Diltiazem (Cardizem) is indicated for the temporary control of a rapid ventricular response in a patient with atrial fibrillation or flutter and paroxysmal supraventricular tachycardia. It is given by continuous infusion after a loading dose given by IV bolus. The other options are incorrect.
The nurse notes in the patient‘s medication orders that the patient will be taking ibutilide. Based on this finding, the nurse interprets that the patient has which disorder?
a. Ventricular ectopy
b. Atrial fibrillation
c. Supraventricular tachycardia
d. Bradycardia
ANS: B
Ibutilide (Corvert) is one of two class III antidysrhythmic drugs available for rapid conversion of these atrial fibrillations and atrial flutters into normal sinus rhythm
Which patient-teaching instructions are appropriate for a patient taking an antidysrhythmic drug? (Select all that apply.)
a. ―Do not chew or crush extended-release forms of medication.‖
b. ―Take the medication with food if gastrointestinal distress occurs.‖
c. ―If a dose is missed, the missed dose should be taken along with the next dose that is due to be taken.‖
d. ―Take the medications with an antacid if gastrointestinal distress occurs.‖
e. ―Limit or avoid the use of caffeine.‖
f. ―The presence of a capsule in the stool should be reported to the physician immediately.‖
ANS: A, B, E
Appropriate teaching instructions for a patient taking an antidysrhythmic drug include: do not chew or crush extended-release forms; if gastrointestinal distress occurs, take the drug with food; and limit or avoid the use of caffeine. Do not double medication doses or take medications with an antacid. The presence of a portion of a capsule or tablet in the stool is actually the wax matrix that carried the medication, which has been absorbed. The physician does not need to be notified.
The nurse is monitoring for adverse effects in a patient who is receiving an amiodarone infusion. Which are adverse effects for amiodarone? (Select all that apply.)
a. Tachycardia
b. Constipation
c. Chest pain
d. QT prolongation
e. Headache
f. Hypotension
g. Blue-gray coloring of the skin on the face, arms, and neck
ANS: B, D, F, G
There are numerous adverse effects of amiodarone, including pulmonary toxicity, thyroid disorders, bradycardia, hypotension, SA node dysfunction, QT prolongation, blue-gray
DIF: Cognitive Level: Applying (Application) Evaluation
TOP: Nursing Process:
coloring of the skin (face, arms, and neck), constipation, and others. Tachycardia, chest pain, and headache are not adverse effects of amiodarone therapy.
