Calcium Channel Blockers Flashcards
A nurse is caring for a patient who is receiving verapamil (Calan) for hypertension and digoxin (Lanoxin) for heart failure. The nurse will observe this patient for:
a. AV blockade.
b. gingival hyperplasia.
c. migraine headaches.
d. reflex tachycardia.
A
Verapamil and digoxin both suppress impulse conduction through the AV node; when the two drugs are used concurrently, the risk of AV blockade is increased. Gingival hyperplasia can occur in rare cases with verapamil, but it is not an acute symptom. Verapamil can be used to prevent migraine, and its use for this purpose is under investigation. Verapamil and digoxin both suppress the heart rate. Nifedipine causes reflex tachycardia.
A patient begins taking nifedipine (Procardia), along with a beta blocker, to treat hypertension. The nurse understands that the beta blocker is used to:
a. reduce flushing.
b. minimize gingival hyperplasia.
c. prevent constipation.
d. prevent reflex tachycardia.
D
Beta blockers are combined with nifedipine to prevent reflex tachycardia. Beta blockers do not reduce flushing, minimize gingival hyperplasia, or prevent constipation. Beta blockers can reduce the adverse cardiac effects of nifedipine.
A nurse is teaching a patient who will begin taking verapamil (Calan) for hypertension about the drug’s side effects. Which statement by the patient indicates understanding of the teaching?
a. “I may become constipated, so I should increase fluids and fiber.”
b. “I may experience a rapid heart rate as a result of taking this drug.”
c. “I may have swelling of my hands and feet, but this will subside.”
d. “I may need to increase my digoxin dose while taking this drug.”
A
Constipation is common with verapamil and can be minimized by increasing dietary fiber and fluids. Verapamil lowers the heart rate. Peripheral edema may occur secondary to vasodilation, and patients should notify their prescriber if this occurs, because the prescriber may use diuretics to treat the condition. Verapamil and digoxin have similar cardiac effects; also, verapamil may increase plasma levels of digoxin by as much as 60%, so digoxin doses may need to be reduced.
A nurse is preparing to assist a nursing student in administering intravenous verapamil to a patient who also receives a beta blocker. The nurse asks the nursing student to discuss the plan of care for this patient. Which statement by the student indicates a need for further teaching?
a. “I will check to see when the last dose of the beta blocker was given.”
b. “I will monitor vital signs closely to assess for hypotension.”
c. “I will monitor the heart rate frequently to assess for reflex tachycardia.”
d. “I will prepare to administer intravenous norepinephrine if necessary.”
C
Reflex tachycardia is not an expected effect; the greater risk is cardiosuppression and bradycardia. Because beta blockers and verapamil have the same effects on the heart, there is a risk of excessive cardiosuppression. To minimize this risk, the two drugs should be given several hours apart. Hypotension may occur and should be treated with IV norepinephrine.
A patient who took an overdose of verapamil has been treated with gastric lavage and a cathartic. The emergency department nurse assesses the patient and notes a heart rate of 50 beats per minute and a blood pressure of 90/50 mm Hg. The nurse will anticipate:
a. administering intravenous norepinephrine (NE) and isoproterenol.
b. assisting with direct-current (DC) cardioversion.
c. placing the patient in an upright position.
d. preparing to administer a beta blocker.
A
Verapamil toxicity can cause bradycardia and hypotension. Isoproterenol should be given to treat bradycardia and NE for hypotension. DC cardioversion is indicated for ventricular tachydysrhythmias, which this patient does not have. Patients with hypotension should be placed in Trendelenburg’s position. Beta blockers will only exacerbate these effects.
A patient who has been taking verapamil (Calan) for hypertension complains of constipation. The patient will begin taking amlodipine (Norvasc) to prevent this side effect. The nurse provides teaching about the difference between the two drugs. Which statement by the patient indicates that further teaching is needed?
a. “I can expect dizziness and facial flushing with nifedipine.”
b. “I should notify the provider if I have swelling of my hands and feet.”
c. “I will need to take a beta blocker to prevent reflex tachycardia.”
d. “I will need to take this drug once a day.”
C
Amlodipine produces selective blockade of calcium channels in blood vessels with minimal effects on the heart. Reflex tachycardia is not common, so a beta blocker is not indicated to prevent this effect. Dizziness and facial flushing may occur. Peripheral edema may occur and should be reported to the provider. Amlodipine is given once daily.
Which are therapeutic uses for verapamil? (Select all that apply.)
a. Angina of effort
b. Cardiac dysrhythmias
c. Essential hypertension
d. Sick sinus syndrome
e. Suppression of preterm labor
A, B, C
Verapamil is used to treat both vasospastic angina and angina of effort. It slows the ventricular rate in patients with atrial flutter, atrial fibrillation, and paroxysmal supraventricular tachycardia. It is a first-line drug for the treatment of essential hypertension. It is contraindicated in patients with sick sinus syndrome. Nifedipine has investigational uses in suppressing preterm labor.
