Question 1

A nurse is obtaining a medication history on a newly admitted patient, who reports taking minoxidil for hypertension. Admission vital signs reveal a heart rate of 78 beats/min and a blood pressure of 120/80 mm Hg. What is an important part of the initial assessment for this patient?

Accepted Answer

Fluid retention is a common and serious adverse effect of minoxidil, because it can lead to cardiac decompensation. If present, a diuretic is indicated. Nausea and vomiting may occur with this drug but is not a serious side effect. Hypertrichosis occurs in about 80% of patients taking the drug, but its effects are cosmetic and not life threatening. It may be important to monitor the blood glucose level in some patients, because the drug can alter glucose tolerance, but this effect is not as serious as fluid retention.

Question 2

A nurse is caring for a patient who will begin taking hydralazine to treat hypertension. Which statement by the patient indicates understanding of the nurse's teaching about this drug?

Accepted Answer

Hydralazine can cause severe reflex tachycardia; a beta blocker is usually given to counter this effect. Postural hypotension is minimal with hydralazine. Patients should be taught to report joint pain, which indicates an SLE syndrome and requires discontinuation of the drug. Minoxidil can cause excessive hair growth, not hydralazine.

Question 3

A patient is admitted with severe hypertensive crisis. The nurse will anticipate administering which medication?

Accepted Answer

Sodium nitroprusside is the drug of choice for hypertensive emergencies and is given intravenously. ACE inhibitors, such as captopril, are not used. Hydralazine may be used but should be given IV. Minoxidil is effective, but its severe side effects make it a second-line drug.

Question 4

A female patient with essential hypertension is being treated with hydralazine 25 mg twice daily. The nurse assesses the patient and notes a heart rate of 96 beats/min and a blood pressure of 110/72 mm Hg. The nurse will request an order to:

Accepted Answer

This patient is showing signs of reflex tachycardia, so a beta blocker is indicated to slow the heart rate. Patients with heart failure who take hydralazine often require the addition of isosorbide dinitrate, which also dilates veins. There is no indication for reducing the dose of hydralazine. A diuretic can be given with hydralazine if sodium and water retention is present.

Question 5

A patient is taking a vasodilator that relaxes smooth muscles in veins. To help minimize drug side effects, the nurse caring for this patient will:

Accepted Answer

Postural hypotension occurs when moving from a supine or seated position to an upright position. It is caused by relaxation of smooth muscle in veins, which allows blood to pool in veins and decreases venous return of blood to the heart. Patients taking such drugs should avoid abrupt transitions to prevent falls. Prolonged use of vasodilators can lead to expansion of blood volume and fluid overload, so increasing fluid intake is not appropriate. Shortness of breath is a symptom associated with heart failure. Tachycardia can occur when the blood pressure drops as a result of the baroreceptor reflex.

Question 6

A nursing student asks a nurse why a patient in hypertensive crisis is receiving both intravenous sodium nitroprusside [Nitropress] and oral hydralazine. The nurse will explain that this is done to prevent:

Accepted Answer

Sodium nitroprusside acts rapidly and is given only intravenously. Rebound hypertension occurs immediately when the IV is stopped, so an oral antihypertensive should be given simultaneously. Cyanide poisoning can occur with sodium nitroprusside, but giving hydralazine does not counter this adverse effect. Hydralazine does not prevent fluid retention or reflex tachycardia.

Question 7

Which patients may receive hydralazine to treat hypertension?

Accepted Answer

Hydralazine may be used in infants as young as 1 month of age, in children, and in older adults. Hydralazine is labeled pregnancy category C and data is lacking regarding transmission of hydralazine in breast-feeding women, so benefits should outweigh risks.

Question 8

A nurse is reviewing the phenomenon of reflex tachycardia with a group of nursing students. Which statement by a student indicates understanding of this phenomenon?

Accepted Answer

Reflex tachycardia, which is a compensatory mechanism in response to decreased blood pressure, can negate the desired effect of a vasodilator by eventually increasing blood pressure. Baroreceptors relay information to the vasomotor center of the medulla; the medulla sends impulses to the heart. Beta blockers are given to counter reflex tachycardia. Reflex tachycardia can be produced by dilation of both arterioles and veins.

Question 9

A nurse is administering a vasodilator that dilates resistance vessels. The nurse understands that this drug will have which effect on the patient?

Accepted Answer

Vasodilators that dilate resistance vessels, or arterioles, cause a decrease in afterload, which allows cardiac output and tissue perfusion to increase. A decrease in preload would be the result of dilation of capacitance vessels, or veins. Dilation of arterioles increases cardiac output. Ventricular contraction results when preload is increased.

Question 10

Which medications are most likely to cause postural hypotension?

Accepted Answer

Postural, or orthostatic, hypotension is defined as a fall in blood pressure related to a change in position. Minoxidil and diltiazem dilate arterioles; therefore, they are not likely to cause postural hypotension. Prazosin, captopril, and losartan all reportedly can cause orthostatic hypotension.

Question 11

The nurse is caring for a patient who is taking a vasodilator that dilates capacitance vessels. The nurse will expect which effect in this patient?

Accepted Answer

Vasodilators that dilate capacitance vessels, or veins, lead to a decrease in venous return to the heart, which reduces preload and the force of ventricular contraction. The resultant effect is a decrease in cardiac work. With a decrease in ventricular contraction, cardiac output is reduced, as is tissue perfusion. Dilation of veins causes a decrease in venous return.

Quiz 46: Vasodilators