Chapter 24, Heart Failure Drugs pharmacology

A patient who is receiving digoxin reports headache, dizziness, nausea, and blurred vision. After assessing the patient, the nurse finds that the patient's pulse rate is 48 beats/min. Which medication should the nurse expect the primary health care provider to prescribe?

Digoxin immune Fab

The nurse reviews a patient's laboratory values, including a digoxin level of 10 ng/mL and serum potassium value of 6.2. Which drug does the nurse ask the primary health care provider to prescribe?

Digoxin immune Fab

Symptoms of digitalis toxicity include anorexia, nausea and vomiting, diarrhea, loss of appetite, bradycardia, hypotension, headache, fatigue, confusion, convulsions, and colored vision. Dehydration and constipation, blood pressure of 100/60 mm Hg, and heart rate of 110 beats per minute are not indications of digitalis toxicity.

Digoxin increases cardiac contractility (positive inotropic effect), decreases heart rate (negative chronotropic effect), and decreases conductivity (negative dromotropic effect). The other options are not applicable.

Nesiritide is a synthetic version of human B-type natriuretic peptide. It has vasodilating effects on both arteries and veins and is used to treat heart failure that is accompanied by dyspnea at rest. Carvedilol is used to treat heart failure and angina. Captopril is used to treat hypertension and congestive heart failure. Metoprolol is used to treat heart failure.

Digoxin increases the force of the contractions in the heart and consequently decreases the heart rate. Ginseng increases the serum concentrations of digoxin. Ginseng tea would relieve vomiting but would also rapidly decrease the patient's heart rate. Digoxin toxicity causes bradycardia but not tachycardia. Digoxin decreases potassium concentrations, and small amounts of potassium will be lost because of vomiting, so the patient would not develop hyperkalemia but would develop hypokalemia. Digoxin, an indirect vasodilator, does not cause hypertension.

While administering a milrinone infusion, the nurse observes that the patient has severe hypotension. What are the priority interventions by the nurse? Select all that apply.

Discontinue the medication and contact the prescriber. Contact the prescriber and decrease the rate of drug infusion.

Which drugs are referred to as positive chronotropic drugs?

Drugs that affect heart rate

The nurse is teaching a patient about the proper diet while taking drugs to treat heart failure. What will the nurse include in the teaching?

"Avoid consuming milk products 2 hours before and after taking the medication."

A patient with congestive heart failure (CHF) is prescribed hydralazine/isosorbide dinitrate. What instruction should the nurse give the patient to minimize side effects?

"Change position carefully while taking the medication."

What is the intravenous loading dose of milrinone for an adult patient?

50 mcg/kg

What is the elimination half-life of valsartan?

6 hours

Concurrent administration of digoxin and verapamil increases the serum level of digoxin by 50%. Digoxin that is administered concurrently with a beta blocker would increase the risk for bradycardia. Taken together, digoxin and verapamil increase, not decrease, the risk for digoxin toxicity. Colestipol, not verapamil, interacts with digoxin, reducing its therapeutic effect.

A serum digoxin level of 0.4 ng/mL is below the normal therapeutic level of 0.5 to 2 ng/mL. Any value over 2 ng/mL is considered above the therapeutic level. The toxic level can only be attained through an extensive application of digoxin administration, for example 5 mEq/L.

A patient with digoxin toxicity is prescribed digoxin immune Fab. What is the correct nursing intervention when giving this medication?

Administer the medication parenterally over 30 minutes the drug.

Which assessment is most important before administering digoxin?

Apical pulse

A patient is taking 0.25 mg of digoxin and 40 mg of furosemide daily. When the nurse enters the room, the patient reports seeing yellow halos around the lights. What is the nurse's first action?

Assess the patient for symptoms of digoxin toxicity.

A patient who is taking digoxin for congestive heart failure (CHF) has severe vomiting. The nurse prepares ginseng tea for the patient to relieve vomiting. What symptom may occur as a result of this nursing action?

Bradycardia

A patient is prescribed digoxin for supraventricular dysrhythmia. The nurse instructs the patient to avoid consuming bran. What is the reason behind this instruction?

Bran decreases digoxin absorption.

Lisinopril is an angiotensin-converting enzyme inhibitor, which causes the kidney to retain potassium, leading to hyperkalemia. Insomnia and abdominal pain are known side effects of nesiritide, not lisinopril. Cardiac dysrhythmia is a side effect of milrinone, not lisinopril.

Bran is a high-fiber food. It binds to the digoxin and affects the absorption and bioavailability of the drug. Bran decreases the absorption of digoxin, so the patient should avoid consuming bran while taking digoxin. Bran is a high-fiber food, and fiber treats constipation. Bran and digoxin do not affect urinary function and therefore do not cause urinary retention. Bran does not produce an additive effect and thus does not increase the digoxin concentration in the body.

A patient who has heart failure is prescribed digoxin. The patient also has hypothyroidism. What is the best nursing intervention to prevent digoxin toxicity?

Calculate the digoxin dose with correct decimal placement.

Hypomagnesemia is the medical term for low levels of serum magnesium. It causes involuntary muscle contraction and relaxation, resulting in twitching. Hypomagnesemia can also cause central nervous system excitability and result in hyperactive reflexes. Edema can be caused by many factors but is not a clinical manifestation of low magnesium levels. Anorexia is sometimes associated with low levels of potassium, but not low levels of magnesium. Insomnia is a side effect of nesiritide but is not caused by low magnesium.

Change in vision, such as a green, yellow, or purple halo surrounding the peripheral field of vision, is a direct symptom of digoxin toxicity. The first action the nurse should take is to assess the patient for the symptoms of digoxin toxicity. Furosemide is a loop diuretic, so it does not relate directly to digoxin toxicity. Medication can be administered as prescribed to remedy the situation. Documentation and reassessment are a part of the nurse's responsibility but will follow the remedy for digoxin toxicity.

A patient is diagnosed with congestive heart failure and is prescribed intravenous digoxin. What interventions will the nurse include when administering the drug to the patient? Select all that apply.

Check the pulse rate before administering the drug. Check the electrolyte levels before administering the drug. Check its compatibility with other drugs being administered.

Which drug would reduce the therapeutic effect of digoxin if it is taken concurrently?

Cholestyramine

Which finding would the nurse expect to see in a patient who is prescribed milrinone?

Decreased platelet count

The nurse should immediately inform the primary health care provider if the patient goes more than 12 hours after a missed dose. Without the primary health care provider's prescription, the nurse should not instruct the patient to stop taking digoxin, because it may be harmful for the patient. The nurse should not instruct the patient to double the next digoxin dose, because it can cause severe toxicity the patient. The nurse should not instruct the patient to take two doses of digoxin with a 6-hour gap, because it may cause severe toxicity in the patient.

Early symptoms of digoxin toxicity are anorexia, nausea, vomiting, and loss of appetite. The patient may also have visual disturbances such as halo vision. Dry cough is a common side effect associated with angiotensin-converting enzyme inhibitors. Dysrhythmia is a sign that occurs in children with digoxin toxicity and occurs at the later stages of digoxin toxicity in adults.

The nurse is teaching a group of nursing students about cardiac glycosides. Which condition indicates an excess dose of cardiac glycosides?

Halo vision

Which complication may be experienced by a patient who is prescribed lisinopril?

Hyperkalemia

A patient is prescribed milrinone. Which is a contraindication to safe administration of milrinone?

Hypokalemia

A patient who receives digoxin therapy states, "I missed one dose of the drug." The nurse learns that the patient hasn't taken the drug for the past 12 hours. What should the nurse do next?

Immediately inform the primary health care provider.

The nurse is providing care to a patient who is prescribed both digoxin and verapamil. Which side effect should the nurse expect the patient to experience?

Increased serum levels of digoxin

A patient is receiving nesiritide. Which symptoms would indicate an overdose? Select all that apply.

Insomnia Dysrhythmia Abdominal pain

A patient has a serum digoxin level of 0.4 ng/mL. What can the nurse interpret from the scenario?

It is below the therapeutic level.

Spironolactone is a potassium-sparing diuretic that increases the retention of potassium. Lisinopril causes hyperkalemia, so prescribing spironolactone may cause complications. Digoxin is a diuretic drug that does not cause any interaction with lisinopril; thus, it can be administered to this patient. Valsartan is a diuretic drug prescribed for hypertension, and it does not cause any adverse effects when taken with lisinopril. Carvedilol is a nonspecific beta blocker that is prescribed for myocardial infarction; it has no adverse interactions with lisinopril, and hence it does not cause complications.

Licorice is an herbal drug. Licorice and digoxin produce a drug-drug interaction. Licorice may increase the risk of cardiac toxicity because of potassium loss. Licorice does not affect the serum sodium concentration; therefore, it does not cause hyponatremia. Licorice does not affect the absorption of digoxin. Licorice has no effect on serum magnesium concentration; therefore, it does not cause hypomagnesemia.

A patient who is prescribed digoxin reports eating licorice to treat inflammation. Why should the nurse advise the patient to stop eating licorice?

Licorice may increase the risk of cardiac toxicity.

A patient with acute heart failure is admitted to the emergency department of a hospital. The patient's medical reports indicate that the patient has asthma and takes telithromycin. Which prescription does the nurse need to obtain from the primary health care provider?

Lisinopril Lisinopril is an ACE inhibitor that prevents the left ventricular dysfunction that arises in the acute period after a myocardial infarction and is thus used to treat acute heart failure. ACE inhibitors are the drugs of choice to initiate treatment for heart failure. Milrinone is a phosphodiesterase inhibitor used to treat heart failure because of its positive inotropic and vasodilatory effects. However, milrinone has adverse effects, such as difficulty breathing, so its use is contraindicated in patients with asthma. Eplerenone, when administered with antifungals like telithromycin, inhibits the action of cytochrome P-450 enzyme 3A4, which results in a decrease in the breakdown of eplerenone in the body. It also increases the risk of side effects such as difficulty breathing, allergy, and drowsiness. Hydralazine is known to decrease the time to hospitalization for heart failure in African-American patients.

A patient with heart failure is prescribed lisinopril. Arrange the order in which lisinopril acts.

Lisinopril inhibits angiotensin-converting enzyme, which is responsible for converting angiotensin I to angiotensin II. Angiotensin II is a potent vasoconstrictor and induces aldosterone secretion. So, lisinopril inhibits aldosterone secretion and prevents sodium and water resorption. This results in a decrease in the circulating blood volume. As the circulating blood volume is reduced, the preload or end diastolic ventricular volume reduces. Consequently, the heart has to put forth less effort to pump blood.

Which assessment finding will alert the nurse to suspect digitalis toxicity?

Loss of appetite with slight bradycardia

Drugs that affect heart rate by accelerating the rate of impulse formation in the sinoatrial node are referred to as positive chronotropic drugs. Drugs that affect blood pressure are referred as vasopressor drugs. Drugs that increase the rate of conduction of electrical impulses through the myocardium are referred to as positive dromotropic drugs. Drugs that increase the force of myocardial contraction are referred to as positive inotropic drugs.

Milk products such as cheese, yogurt, and ice cream decrease the absorption of heart failure drugs, so they should not be taken 2 hours before and after taking the medication. Drinking large amounts of water increases blood pressure and increases the workload on the heart in patients with heart failure. Bran, rich in fiber and protein, should be avoided only 2 hours before or after the medication, not completely. Bran slows down the absorption of the medication only if taken within 2 hours of taking the medication. Antacids form complexes with the medication and render it unavailable for absorption. Also, antacids may increase the blood sodium and fluid levels, resulting in hypertension.

If toxicity occurs and digoxin rises to a life-threatening level, the nurse should administer the antidote, digoxin immune Fab, as ordered. It is given parenterally over 30 minutes, and in some scenarios it is given as an intravenous bolus (e.g., if cardiac arrest is imminent). All vials of the drug need to be refrigerated. The nurse should closely monitor blood pressure, apical pulse rate and rhythm, electrocardiogram, and serum potassium levels, and record the findings. Document baseline data, and begin observing closely for changes in assessment findings such as changes in muscle strength, occurrence of tremors and muscle cramping, changes in mental status, irregular cardiac rhythms (from hypokalemia), confusion, thirst, and cold clammy skin (from.

Milrinone is a phosphodiesterase inhibitor with an intravenous loading dose of 50 mcg/kg. A pediatric intravenous dose of digoxin is 35 mcg/kg, divided into three doses. A pediatric oral dose of digoxin is 40 mcg/kg, and is divided into three doses. An intravenous continuous infusion dose of milrinone is 0.75 mcg/kg/min for an adult patient.

Cardiac glycosides cause halo vision, a condition in which colored or luminous rings are seen around lights. Intake of diuretics inhibits sodium and water resorption, thereby causing frequent urination. Angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and beta blockers cause dizziness when patients stand up. Amiodarone, an antidysrhythmic drug, causes abnormal intolerance to light, called photophobia.

Milrinone is a phosphodiesterase inhibitor. Because milrinone decreases serum potassium concentration, the nurse should check the patient's history for hypokalemia. Administration of milrinone to a patient who has hypokalemia may lead to severe complications. Milrinone can be safely administered to patients with diabetes, skin diseases, or ear infections because it does not cause any complications when a patient has these health conditions.

Positive dromotropic medications accelerate conduction. Angiotensin-converting enzyme (ACE) inhibitors inhibit angiotensin-converting enzyme. Positive chronotropic medications increase the heart rate. Positive inotropic medications increase the force of myocardial contraction.

Milrinone lactate is a phosphodiesterase inhibitor administered intravenously for short-term treatment in patients with heart failure not responding adequately to digoxin, diuretics, or other vasodilators. Blood pressure and heart rate should be closely monitored. Digoxin is not administered with the milrinone but is usually tried before treatment with milrinone. Furosemide is not necessarily administered after the milrinone, although it could be. It is not, however, administered routinely via intravenous infusion. Lactated Ringer solution does not have to be administered with milrinone.

A patient is being treated for short-term management of heart failure with milrinone. What is the primary nursing action?

Monitor blood pressure continuously.

Which medication is appropriate for a patient who is diagnosed with heart failure who is experiencing dyspnea at rest?

Nesiritide

Patients who have been administered milrinone must be examined for signs of hypotension. If there is a large decrease in blood pressure, the medication must be discontinued and the nurse must report to the primary health care provider. If the hypotension is not very intense, then the primary health care provider must be notified and the rate of the infusion must be reduced until the primary health care provider arrives. When administered through inhalation route, milrinone would also cause hypotension. Administering sympathomimetic agents to increase blood pressure without notifying the prescriber may worsen the health condition of the patient. Administering the medication by decreasing the dose would still aggravate the symptoms of hypotension if the patient already has severe hypotension.

Nesiritide is recombinant human B-type natriuretic peptide. Insomnia, dysrhythmia, and abdominal pain are adverse effects of nesiritide. The drug decreases blood pressure and causes hypotension. It does not cause hypertension. Nesiritide does not have any effect on blood glucose concentrations; therefore, it does not cause hyperglycemia.

Valsartan is an angiotensin II receptor blocker. The elimination half-life of valsartan is 6 hours. The elimination half-life of lisinopril is 1 hour. The onset of action of valsartan is 2 hours. The duration of action of valsartan is 12 hours.

Patients with cardiac disease who have a marked limitation in physical activity are classified as class III according to the NYHA's functional classification for cardiac disease. They are comfortable at rest. Activities requiring minimal effort in such patients would cause fatigue, palpitation, dyspnea, or anginal pain. Patients with cardiac disease who have no limitation of physical activity are classified under class I of the NYHA's functional classification. Patients with cardiac disease who are comfortable at rest but in whom ordinary physical activities result in fatigue, palpitation, difficulty breathing, or anginal pain belong to class II of the NYHA's functional classification. Patients with cardiac disease resulting in an inability to perform any physical activity without discomfort are classified in class IV of the NYHA's functional classification. Symptoms of heart failure or anginal syndrome may be present even at rest.

Which patients with heart disease would be classified within class III of the New York Heart Association's (NYHA) functional classification for cardiac disease?

Patients with marked limitation of physical activity

What are the therapeutic effects of digoxin?

Positive inotropic, negative chronotropic, and negative dromotropic

Which medication will enhance the negative inotropic effect of digoxin?

Quinidine

Digoxin immune Fab is specifically prescribed for severe digoxin overdose and for the reversal of such life-threatening cardiotoxic effects as severe bradycardia, advanced heart block, ventricular tachycardia or fibrillation, and severe hyperkalemia. Atropine is used as an antidote for anticholinesterase inhibitor toxicity or poisoning. Epinephrine is considered a potent vasoconstrictor. Potassium supplements help in the production of electrolytes in the intracellular fluid.

Quinidine blocks calcium channels in the myocardium and enhances the negative inotropic effect of digoxin. Sucralfate decreases the oral absorption of digoxin and reduces the therapeutic effect of digoxin. Amiodarone and cyclosporine decrease digoxin clearance and increase digoxin levels in the body by 50%.

While assessing a patient who has heart failure, the nurse finds that the patient has been taking lisinopril for hypertension. Which drug in the patient's prescription should the nurse question?

Spironolactone

A patient with congestive heart failure is prescribed furosemide and milrinone by the primary health care provider. The nurse administers them simultaneously through the same intravenous line. What is a possible consequence of this nursing action?

Therapeutic effects of furosemide will not be seen in the patient.

Which statement is true about positive dromotropic medications?

They accelerate conduction in the heart.

Which are expected clinical manifestations of hypomagnesemia? Select all that apply.

Twitching Hyperactive reflexes

Which medication blocks angiotensin II receptors?

Valsartan

Cholestyramine interacts with digoxin by decreasing its absorption, which results in a reduced therapeutic effect. Quinidine, when given along with digoxin, blocks the calcium channels in the myocardium, resulting in enhanced bradycardic and negative inotropic effects of digoxin. Verapamil and cyclosporine decrease the clearance of digoxin, which then increases digoxin levels, resulting in digoxin toxicity.

Valsartan is an angiotensin II receptor blocker. It prevents angiotensin II from binding with angiotensin II receptors, thereby blocking the action of angiotensin II. Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor. Metoprolol is a beta blocker. Eplerenone is an aldosterone inhibitor.

Which medication is contraindicated for a patient with heart failure who is taking digoxin?

Verapamil

Headache, dizziness, nausea, blurred vision, and slowed pulse are symptoms of digoxin toxicity. Digoxin immune Fab should be administered to the patient to manage the digoxin toxicity. Digoxin immune Fab is an antibody that recognizes digoxin as an antigen and forms an antigen-antibody complex with the drug, thus inactivating the free digoxin. It prevents further complications. Milrinone, nesiritide, and dobutamine do not have any effect on serum digoxin concentrations. Therefore, these drugs are not useful for the management of digoxin toxicity. Milrinone is a phosphodiesterase inhibitor and is used in the treatment of heart failure. Nesiritide is a recombinant human B-type natriuretic peptide used to treat life-threatening heart failure. Dobutamine is a beta 1-selective vasoactive adrenergic drug used to treat heart failure.

Verapamil is contraindicated for use in heart failure, because it increases the serum digoxin level, enhances the bradycardic effects of digoxin, and aggravates the patient's heart condition. In addition, the action of verapamil can depress myocardial contractility, opposing the action of digoxin. Valsartan and furosemide are indicated in the treatment of heart failure to reduce peripheral vascular resistance and to promote diuresis, respectively. Phenytoin should not be restricted for use in heart failure, although it can be used as an antidysrhythmic agent, to affect ventricular contractions and not the sinoatrial node.

Digoxin must be administered only if the patient has a pulse rate between 60 and 100 beats/min. Hypokalemia and hypomagnesemia may precipitate digoxin toxicity, and thus electrolyte levels should be checked. If digoxin is concomitantly administered with any other drug in solution form, then its compatibility must be checked, because digoxin is incompatible with many of them. Unless otherwise specified, digoxin should be administered using an infusion pump; intravenous push should be used only if specified by the primary health care provider. Intake of high-fiber diet of foods such as bran interferes with the absorption of digoxin only if it is given orally. Diet has no effect when digoxin is administered parenterally.

When furosemide is administered simultaneously with milrinone through the same intravenous line, furosemide is precipitated. So, the therapeutic actions of furosemide are not seen. Furosemide does not increase the serum concentrations of milrinone, so toxic effects of milrinone will not be seen in the patient. Furosemide is precipitated while being administered, consequently making it unavailable to influence therapeutically. Milrinone would produce its therapeutic actions because it is not precipitated.

The nurse is monitoring an adult patient who has been administered digoxin. The nurse suspects that the patient is developing digoxin toxicity. For which symptoms will the nurse monitor the patient? Select all that apply.

anorexia vomiting visual disturbances

Which medication is used to treat supraventricular dysrhythmia?

digoxin