NCLEX Pharmacology: Cardiovascular Medications 1 — Questions and Answers

Question 1: A patient is prescribed metoprolol succinate. Which condition is this medication primarily used to treat?

Atrial fibrillation
Heart failure and hypertension (Correct answer)
Pulmonary hypertension
Deep vein thrombosis

Correct answer: Heart failure and hypertension

Metoprolol succinate is a beta-1 selective blocker used to treat heart failure, hypertension, and angina by reducing heart rate and myocardial oxygen demand.

Metoprolol succinate (Toprol XL) is a cardioselective beta-1 adrenergic blocker. It reduces heart rate, contractility, and blood pressure, making it effective for heart failure, hypertension, and stable angina. In heart failure, it reduces mortality by blocking the harmful chronic activation of the sympathetic nervous system. Nurses should monitor heart rate and blood pressure before administration and hold if HR < 60 or systolic BP < 90 mmHg.

Question 2: The nurse is administering digoxin. Which assessment finding requires holding the medication and notifying the provider?

Heart rate of 68 bpm
Heart rate of 54 bpm (Correct answer)
Blood pressure of 128/80 mmHg
Potassium level of 4.0 mEq/L

Correct answer: Heart rate of 54 bpm

Digoxin should be held if the apical heart rate is less than 60 bpm in adults. A rate of 54 indicates bradycardia and risk for digoxin toxicity.

Digoxin is a cardiac glycoside used for heart failure and atrial fibrillation. It increases vagal tone and slows AV node conduction, which can cause bradycardia. The standard nursing practice is to hold digoxin and notify the provider if the apical heart rate is below 60 bpm in adults. Signs of toxicity include nausea, vomiting, visual disturbances (yellow-green halos), and dysrhythmias. Hypokalemia increases the risk of toxicity.

Question 3: A patient taking warfarin has an INR of 4.8. Which action should the nurse take first?

Administer the next scheduled dose
Hold the warfarin and notify the provider (Correct answer)
Give vitamin K immediately without an order
Increase the warfarin dose to stabilize the INR

Correct answer: Hold the warfarin and notify the provider

An INR of 4.8 is supratherapeutic (therapeutic range 2–3 for most indications), indicating a high bleeding risk. The nurse should hold warfarin and notify the provider for further instructions.

Warfarin is a vitamin K antagonist used to prevent thromboembolic events. The therapeutic INR is typically 2.0–3.0 (or 2.5–3.5 for mechanical heart valves). An INR of 4.8 is significantly elevated and places the patient at high bleeding risk. The nurse should hold the medication and contact the provider. If serious bleeding occurs, vitamin K (phytonadione) and/or fresh frozen plasma may be administered as reversal agents. All bleeding precautions should be implemented.

Question 4: Which electrolyte imbalance most increases the risk of digoxin toxicity?

Hypernatremia
Hypokalemia (Correct answer)
Hypermagnesemia
Hypercalcemia

Correct answer: Hypokalemia

Hypokalemia (low potassium) increases the risk of digoxin toxicity because digoxin and potassium compete for the same binding sites on the Na+/K+ ATPase pump.

Digoxin inhibits the Na+/K+ ATPase pump. Potassium normally competes with digoxin for binding at this pump. When serum potassium is low (hypokalemia), digoxin binds more readily, increasing its effect and risk of toxicity. Diuretics commonly cause hypokalemia, so patients on both digoxin and diuretics require careful potassium monitoring. Signs of digoxin toxicity include nausea, vomiting, bradycardia, heart block, and visual changes. Normal potassium range: 3.5–5.0 mEq/L.

Question 5: A patient is starting lisinopril for hypertension. Which side effect should the nurse include in patient teaching?

Hypertrichosis
Dry, persistent cough (Correct answer)
Increased urination
Weight gain

Correct answer: Dry, persistent cough

ACE inhibitors like lisinopril commonly cause a dry, persistent cough due to accumulation of bradykinin. This is a known side effect and may require switching to an ARB.

Lisinopril is an ACE (angiotensin-converting enzyme) inhibitor used to treat hypertension, heart failure, and diabetic nephropathy. A common side effect is a dry, persistent, non-productive cough, occurring in up to 20% of patients, caused by accumulation of bradykinin. Patients who develop this cough are often switched to an angiotensin II receptor blocker (ARB). Other important side effects include hyperkalemia, hypotension (especially first-dose), and angioedema (a rare but life-threatening complication requiring immediate discontinuation).

Question 6: The nurse is caring for a patient receiving IV heparin. Which lab value is used to monitor heparin therapy?

PT/INR
aPTT (Correct answer)
Platelet count only
Bleeding time

Correct answer: aPTT

The aPTT (activated partial thromboplastin time) is used to monitor unfractionated heparin therapy. Therapeutic range is typically 60–100 seconds (1.5–2.5 times normal).

Unfractionated heparin (UFH) works by enhancing antithrombin III activity, inhibiting thrombin and factor Xa. The aPTT is used to monitor its therapeutic effect. The therapeutic aPTT is generally 60–100 seconds or 1.5–2.5 times the control value. Normal aPTT is 25–40 seconds. PT/INR is used to monitor warfarin. Anti-Xa levels are used to monitor low-molecular-weight heparins (LMWH) like enoxaparin. Nurses should also monitor platelet counts to detect heparin-induced thrombocytopenia (HIT), a serious complication.

Question 7: A patient with atrial fibrillation is prescribed amiodarone. Which finding requires immediate provider notification?

Heart rate of 72 bpm
QTc interval of 520 milliseconds (Correct answer)
Blood pressure of 118/76 mmHg
Potassium of 4.2 mEq/L

Correct answer: QTc interval of 520 milliseconds

Amiodarone prolongs the QT interval. A QTc of 520 ms significantly exceeds the safe threshold (men >450 ms, women >470 ms) and raises risk for torsades de pointes, a life-threatening dysrhythmia.

Amiodarone is a class III antiarrhythmic that prolongs the QT interval by blocking potassium channels. A QTc >500 ms (or some protocols >480 ms) raises the risk of torsades de pointes (TdP), a polymorphic ventricular tachycardia that can degenerate into ventricular fibrillation. The nurse must monitor ECG continuously during IV amiodarone administration and report QTc prolongation. Other serious toxicities include pulmonary fibrosis, thyroid dysfunction (hypo or hyper), hepatotoxicity, and corneal microdeposits.

Question 8: Which teaching point is most important for a patient prescribed nitroglycerin sublingual tablets for angina?

Take the tablet with a full glass of water
Take up to 3 tablets every 5 minutes; call 911 if pain persists after the third tablet (Correct answer)
Store the tablets in a plastic weekly pill organizer
Take the tablet with food to avoid GI upset

Correct answer: Take up to 3 tablets every 5 minutes; call 911 if pain persists after the third tablet

For acute angina, nitroglycerin SL may be repeated every 5 minutes up to 3 doses. If pain is unrelieved after 3 tablets, the patient should call 911 as this may indicate MI.

Nitroglycerin (NTG) sublingual tablets are first-line for acute angina attacks. The standard protocol is: place one tablet under the tongue, wait 5 minutes; if no relief, take a second tablet; wait 5 more minutes; if still no relief, take a third tablet and call 911. After 3 tablets (15 minutes) without relief, MI must be suspected. Tablets should be stored in their original amber glass bottle, protected from light and heat, as they degrade quickly. Headache and hypotension are common side effects. Patients should sit or lie down when taking NTG to prevent falls.

Question 9: The nurse is administering amlodipine (Norvasc) to a patient. Which food should the nurse advise the patient to avoid?

Dairy products
Grapefruit juice (Correct answer)
Leafy green vegetables
Bananas

Correct answer: Grapefruit juice

Grapefruit juice inhibits CYP3A4 enzymes in the gut, increasing amlodipine blood levels and risk of hypotension and adverse effects.

Amlodipine is a dihydropyridine calcium channel blocker used for hypertension and angina. Grapefruit juice contains furanocoumarins that inhibit CYP3A4, an enzyme responsible for metabolizing many calcium channel blockers including amlodipine. This inhibition increases drug bioavailability, potentially causing excessive hypotension, reflex tachycardia, and edema. Patients should be taught to avoid grapefruit and grapefruit juice. Leafy greens are a concern for warfarin (vitamin K); bananas increase potassium and are a concern with certain medications; dairy is not specifically relevant to amlodipine.

Question 10: A nurse is educating a patient about taking atorvastatin (Lipitor). Which instruction is most important?

Take the medication with antacids to prevent GI upset
Report unexplained muscle pain or weakness immediately (Correct answer)
Avoid taking the medication if fasting cholesterol is normal
The medication can be stopped once cholesterol levels normalize

Correct answer: Report unexplained muscle pain or weakness immediately

Statins can cause myopathy or rhabdomyolysis, a serious condition involving muscle breakdown. Unexplained muscle pain, weakness, or dark urine should be reported immediately.

Atorvastatin is an HMG-CoA reductase inhibitor (statin) used to reduce LDL cholesterol and cardiovascular event risk. A major concern with statins is myopathy, ranging from mild myalgia to severe rhabdomyolysis, where extensive muscle breakdown releases myoglobin into the bloodstream and can cause acute kidney injury. Patients should report unexplained muscle pain, weakness, or tenderness, especially with dark (cola-colored) urine. CK (creatine kinase) levels are monitored. Statins are generally taken long-term even when cholesterol levels improve. Liver function tests are also monitored during therapy.

Question 11: Which assessment finding is a priority concern when a patient is receiving IV furosemide (Lasix) for heart failure?

Urine output of 200 mL/hour
Serum potassium of 2.8 mEq/L (Correct answer)
Weight loss of 1 lb in 24 hours
Blood pressure of 130/82 mmHg

Correct answer: Serum potassium of 2.8 mEq/L

Furosemide causes potassium loss (hypokalemia). A potassium of 2.8 mEq/L is below normal (3.5–5.0) and can cause life-threatening cardiac dysrhythmias, requiring immediate intervention.

Furosemide is a loop diuretic that inhibits the Na-K-2Cl cotransporter in the ascending loop of Henle, causing excretion of sodium, potassium, chloride, and water. Hypokalemia (K+ < 3.5 mEq/L) is a major complication. At 2.8 mEq/L, the patient is at risk for serious ventricular dysrhythmias, muscle weakness, and if taking digoxin, enhanced digoxin toxicity. Potassium replacement (oral or IV) and continuous cardiac monitoring are indicated. Nurses should also monitor for hyponatremia, dehydration, and ototoxicity with high IV doses.

Question 12: A patient is receiving IV dopamine. The nurse notes the infusion infiltrated the IV site. Which action is the priority?

Slow the infusion rate and continue monitoring
Stop the infusion and prepare to administer phentolamine locally (Correct answer)
Apply a warm compress to the site
Restart the IV with a larger gauge catheter

Correct answer: Stop the infusion and prepare to administer phentolamine locally

Dopamine extravasation causes severe vasoconstriction and local tissue necrosis. Phentolamine (an alpha-adrenergic blocker) should be infiltrated locally to counteract vasoconstriction and prevent tissue damage.

Dopamine is a catecholamine vasopressor used to treat cardiogenic shock and hypotension. At higher doses it activates alpha-1 receptors causing intense vasoconstriction. If it infiltrates subcutaneous tissue, it causes severe vasoconstriction and ischemic tissue necrosis. The antidote is phentolamine mesylate, an alpha-adrenergic blocking agent, injected locally into the affected area within 12 hours of extravasation. The infusion must be stopped immediately and a new IV started proximal to the site. IV dopamine should ideally be administered via a central line to prevent extravasation.

Question 13: A patient taking spironolactone should be monitored for which electrolyte imbalance?

Hypokalemia
Hyperkalemia (Correct answer)
Hyponatremia
Hypernatremia

Correct answer: Hyperkalemia

Spironolactone is a potassium-sparing diuretic that blocks aldosterone, causing sodium and water excretion while retaining potassium, which can lead to hyperkalemia.

Spironolactone is an aldosterone antagonist (potassium-sparing diuretic) used for heart failure, hypertension, and hyperaldosteronism. By blocking aldosterone receptors in the collecting duct, it prevents sodium reabsorption and potassium excretion. This can lead to hyperkalemia (elevated potassium > 5.0 mEq/L), which is dangerous because it can cause cardiac dysrhythmias. Nurses should monitor potassium levels regularly. ACE inhibitors and ARBs also raise potassium, so the combination with spironolactone requires close monitoring. Patients should avoid potassium supplements and high-potassium foods.

Question 14: The nurse is teaching a patient about clopidogrel (Plavix) after coronary stent placement. Which statement indicates further teaching is needed?

I will take this medication every day as prescribed
I can stop this medication if I develop a minor headache (Correct answer)
I will tell my dentist I am taking this blood thinner
I should avoid aspirin unless my cardiologist approves it

Correct answer: I can stop this medication if I develop a minor headache

Stopping clopidogrel early after coronary stent placement greatly increases the risk of stent thrombosis, a life-threatening event. Minor side effects do not justify stopping therapy without provider guidance.

Clopidogrel is an ADP receptor (P2Y12) antiplatelet agent used alongside aspirin (dual antiplatelet therapy, DAPT) after coronary stent placement. Premature discontinuation, even briefly, can cause acute stent thrombosis—a sudden blockage of the stent resulting in MI or death. Patients must continue therapy for the full prescribed duration (typically 6–12 months for drug-eluting stents). Any procedure requiring interruption must be coordinated with the cardiologist. Patients should inform all healthcare providers including dentists. Headache alone does not warrant stopping the medication.

Question 15: Which antihypertensive class is contraindicated in pregnancy due to risk of fetal renal damage?

Calcium channel blockers
ACE inhibitors (Correct answer)
Beta-blockers
Methyldopa

Correct answer: ACE inhibitors

ACE inhibitors are teratogenic and contraindicated in pregnancy (especially 2nd and 3rd trimesters) due to risk of fetal renal dysplasia, oligohydramnios, and neonatal death.

ACE inhibitors (e.g., lisinopril, enalapril) and ARBs are contraindicated in pregnancy, particularly after the first trimester. They block angiotensin II, which is critical for fetal renal development. Exposure can cause fetal hypotension, renal tubular dysplasia, oligohydramnios (reduced amniotic fluid due to decreased fetal urine output), pulmonary hypoplasia, and neonatal death. The FDA classifies them as Category D (2nd/3rd trimester). Safe alternatives for hypertension in pregnancy include methyldopa, labetalol, and nifedipine. Methyldopa has the most safety data in pregnancy.

Question 16: A patient receiving alteplase (tPA) for acute ischemic stroke develops sudden severe headache and changes in consciousness. The nurse should prioritize which action?

Administer an analgesic for the headache
Stop the infusion immediately and notify the provider (Correct answer)
Slow the infusion and obtain a blood pressure
Continue the infusion and document the findings

Correct answer: Stop the infusion immediately and notify the provider

Sudden severe headache and altered consciousness during tPA suggest intracranial hemorrhage, a life-threatening complication. The infusion must be stopped immediately and the provider notified.

Alteplase is a thrombolytic (tissue plasminogen activator) used in acute ischemic stroke within 3–4.5 hours of symptom onset. Its most feared complication is intracranial hemorrhage (ICH), occurring in approximately 6% of patients. Signs include sudden severe headache ('thunderclap'), decreased LOC, new neurological deficits, hypertension, and bradycardia (Cushing's triad). Immediate actions: stop the infusion, notify the provider and stroke team, prepare for emergent CT scan, and have reversal agents ready (cryoprecipitate, fresh frozen plasma). No blood thinners for 24 hours after tPA per protocol.

Question 17: A patient is prescribed carvedilol for heart failure. Which statement about this medication is accurate?

It is a selective beta-1 blocker only
It blocks both alpha-1 and beta receptors (Correct answer)
It increases heart rate to improve cardiac output
It is used only for acute heart failure exacerbations

Correct answer: It blocks both alpha-1 and beta receptors

Carvedilol is a non-selective beta-blocker that also blocks alpha-1 adrenergic receptors. This dual blockade reduces heart rate, contractility, and peripheral vascular resistance.

Carvedilol (Coreg) is a third-generation beta-blocker with additional alpha-1 receptor blocking activity. By blocking both receptors, it reduces heart rate, myocardial contractility, and peripheral vascular resistance, making it effective for heart failure and hypertension. Unlike selective beta-1 blockers (metoprolol), its alpha-blockade provides additional vasodilation. It improves mortality in chronic stable heart failure with reduced ejection fraction (HFrEF). It should be started at low doses and titrated gradually, and should not be started during acute decompensated heart failure. Blood pressure and heart rate monitoring are essential.

Question 18: A nurse is caring for a patient on a heparin infusion who develops a platelet count drop from 280,000 to 62,000 over 5 days. What condition does this suggest?

Disseminated intravascular coagulation (DIC)
Heparin-induced thrombocytopenia (HIT) (Correct answer)
Aplastic anemia
Idiopathic thrombocytopenic purpura (ITP)

Correct answer: Heparin-induced thrombocytopenia (HIT)

A platelet drop of >50% occurring 5–10 days after starting heparin is classic for HIT, an immune-mediated reaction that paradoxically causes thrombosis despite low platelets.

Heparin-induced thrombocytopenia (HIT) is an immune-mediated adverse reaction to heparin where antibodies form against the heparin-platelet factor 4 (PF4) complex. Despite low platelets, HIT causes a prothrombotic state (HIT is also called 'white clot syndrome' due to white platelet-rich thrombi). The classic presentation: platelet count drops 50% or more, occurring 5–10 days after heparin initiation. Management: immediately discontinue ALL forms of heparin (including flushes), and start a direct thrombin inhibitor (argatroban or bivalirudin). Warfarin must not be started until platelets recover. Lab: HIT antibody ELISA test, serotonin release assay.

Question 19: Which patient should the nurse question before administering a prescribed dose of IV metoprolol?

Patient with hypertension
Patient with acute asthma exacerbation (Correct answer)
Patient with stable angina
Patient with sinus tachycardia

Correct answer: Patient with acute asthma exacerbation

Beta-blockers like metoprolol can cause bronchoconstriction and are relatively contraindicated in patients with reactive airway diseases such as asthma or COPD.

Although metoprolol is a beta-1 selective blocker, at higher doses it can lose selectivity and block beta-2 receptors in the bronchi. Beta-2 receptor blockade causes bronchoconstriction, which is dangerous in patients with asthma or COPD. In an acute asthma exacerbation, beta-2 receptors are needed for bronchodilation (e.g., albuterol works via beta-2 agonism). Administering a beta-blocker can worsen bronchospasm and precipitate respiratory failure. The nurse should hold the medication and clarify with the provider. Cardioselective beta-blockers may be used cautiously in mild/stable COPD when the cardiac benefit outweighs the risk.

Question 20: A patient taking simvastatin is prescribed clarithromycin for a respiratory infection. The nurse should recognize this combination places the patient at risk for:

Decreased antibiotic effectiveness
Increased statin levels and rhabdomyolysis (Correct answer)
Hypertensive crisis
Reduced anticoagulation effect

Correct answer: Increased statin levels and rhabdomyolysis

Clarithromycin inhibits CYP3A4, which metabolizes simvastatin. This inhibition increases statin blood levels dramatically, raising the risk of myopathy and rhabdomyolysis.

Simvastatin is metabolized by the CYP3A4 enzyme system. Clarithromycin is a potent CYP3A4 inhibitor, meaning it blocks the enzyme that breaks down simvastatin. This leads to markedly elevated statin plasma levels and a substantially increased risk of myopathy and rhabdomyolysis. This is a significant drug interaction that requires either temporary statin suspension during antibiotic therapy or switching to an antibiotic that does not inhibit CYP3A4 (e.g., azithromycin, which has minimal CYP3A4 inhibition). Nurses should review drug interactions before administering combination regimens.

Question 21: A patient on continuous IV nitroglycerin infusion develops a headache. What is the appropriate nursing response?

Stop the infusion immediately
Administer acetaminophen as ordered and continue monitoring (Correct answer)
Reposition the patient and increase the infusion rate
Obtain an ECG and notify the provider

Correct answer: Administer acetaminophen as ordered and continue monitoring

Headache is the most common side effect of nitroglycerin due to cerebral vasodilation. Acetaminophen can be administered for relief while the infusion continues as prescribed.

Nitroglycerin causes vasodilation of venous and arterial blood vessels, including cerebral vessels. Headache is the most frequently reported side effect and is an expected, not dangerous, response. It does not require stopping the infusion. Acetaminophen is the analgesic of choice (avoid NSAIDs due to cardiovascular effects). The nurse should document the complaint, administer prescribed analgesics, and continue monitoring blood pressure. Headaches often diminish with continued therapy. The nurse should differentiate this from more serious neurological symptoms that could indicate other complications.

Question 22: A patient is prescribed sacubitril/valsartan (Entresto) for heart failure. Which medication combination is absolutely contraindicated with this drug?

Loop diuretics
ACE inhibitors (Correct answer)
Beta-blockers
Aldosterone antagonists

Correct answer: ACE inhibitors

Sacubitril/valsartan (an ARNI) must not be combined with ACE inhibitors due to risk of life-threatening angioedema. A 36-hour washout period is required when switching.

Sacubitril/valsartan (Entresto) is an angiotensin receptor-neprilysin inhibitor (ARNI). The sacubitril component inhibits neprilysin, which breaks down natriuretic peptides and bradykinin. When combined with an ACE inhibitor (which also raises bradykinin by inhibiting its breakdown), bradykinin accumulates excessively, dramatically increasing the risk of life-threatening angioedema. Therefore, a 36-hour washout period after stopping an ACE inhibitor is mandatory before starting Entresto. Entresto improves mortality in HFrEF and is recommended in guidelines as a replacement for ACE inhibitors or ARBs in eligible patients.

Question 23: The nurse is administering IV vancomycin. The patient develops flushing, erythema, and hypotension during the infusion. What action should the nurse take?

Stop the infusion and administer epinephrine
Slow the infusion rate and administer diphenhydramine (Correct answer)
Continue the infusion and document findings
Discontinue vancomycin and change to a different antibiotic

Correct answer: Slow the infusion rate and administer diphenhydramine

This describes 'Red Man Syndrome,' a non-immune-mediated reaction caused by too-rapid vancomycin infusion. Slowing the rate and giving diphenhydramine typically resolves symptoms.

Red Man Syndrome is a common adverse reaction to vancomycin infusion, characterized by flushing, erythema (redness), pruritus of the face/neck/chest, and hypotension. It is not a true allergic reaction but is caused by mast cell degranulation and histamine release triggered by rapid infusion. Management includes slowing or temporarily stopping the infusion and administering diphenhydramine (antihistamine). Vancomycin should be infused over at least 60 minutes (or longer for doses > 1 g). This is distinct from anaphylaxis, which requires epinephrine. Premedicating with diphenhydramine can prevent recurrence in susceptible patients.

Question 24: A patient with coronary artery disease is prescribed aspirin 81 mg daily. Which is the primary purpose of this therapy?

To reduce fever associated with MI
To inhibit platelet aggregation and prevent clot formation (Correct answer)
To reduce LDL cholesterol levels
To decrease myocardial oxygen demand

Correct answer: To inhibit platelet aggregation and prevent clot formation

Low-dose aspirin inhibits thromboxane A2 production by irreversibly blocking COX-1, reducing platelet aggregation and lowering the risk of arterial thrombosis and MI.

Aspirin irreversibly inhibits COX-1 (cyclooxygenase-1), blocking the synthesis of thromboxane A2 in platelets. Thromboxane A2 promotes platelet aggregation and vasoconstriction. By inhibiting this pathway, low-dose aspirin (81 mg) reduces platelet clumping and the formation of arterial blood clots, lowering the risk of MI and ischemic stroke in patients with CAD or prior cardiovascular events. Since platelets cannot regenerate COX-1 (they lack nuclei), the effect lasts the lifetime of the platelet (~7–10 days). Aspirin does not significantly affect LDL cholesterol or myocardial oxygen demand.

Question 25: A patient is receiving IV dobutamine for acute heart failure. Which hemodynamic effect does the nurse anticipate?

Increased peripheral vascular resistance
Increased cardiac contractility and cardiac output (Correct answer)
Decreased heart rate and blood pressure
Decreased renal perfusion

Correct answer: Increased cardiac contractility and cardiac output

Dobutamine is a beta-1 agonist that increases cardiac contractility (positive inotropic effect), increasing cardiac output without significantly raising peripheral vascular resistance.

Dobutamine is a synthetic catecholamine that primarily stimulates beta-1 adrenergic receptors, producing a strong positive inotropic effect (increased contractility) and moderate chronotropic effect (mild increase in heart rate). Unlike dopamine, dobutamine tends to decrease peripheral vascular resistance (afterload reduction), improving cardiac output without significantly raising blood pressure. It is used in acute decompensated heart failure and cardiogenic shock when augmenting pump function is the priority. Continuous cardiac monitoring is required as it can cause tachycardia and dysrhythmias. Blood pressure and urinary output are key monitoring parameters.

Question 26: The nurse is caring for a patient receiving IV adenosine for supraventricular tachycardia (SVT). Which action is most important before administration?

Obtain a 12-lead ECG and wait for physician confirmation
Ensure a large bore IV is placed in the antecubital fossa and flush rapidly (Correct answer)
Administer the medication over 5 minutes for best effect
Place the patient in Trendelenburg position

Correct answer: Ensure a large bore IV is placed in the antecubital fossa and flush rapidly

Adenosine has an extremely short half-life (~10 seconds). It must be given as a rapid IV push followed immediately by a fast flush to ensure it reaches central circulation before it degrades.

Adenosine is used for acute termination of SVT. It works by transiently blocking AV node conduction, interrupting the reentrant circuit. Because its half-life is approximately 5–10 seconds, it must be administered via rapid IV push directly into a large bore antecubital or more proximal IV line, followed immediately by a rapid saline flush (20 mL fast push) to ensure the drug reaches the central circulation before it is degraded. A distal hand/foot IV is inadequate. A brief period of asystole or bradycardia is expected after administration. Continuous cardiac monitoring is mandatory. Warn the patient they may experience a brief sensation of chest pressure or flushing.

Question 27: A patient is taking warfarin and reports starting to take herbal St. John's Wort. The nurse understands this interaction will likely cause:

Increased warfarin levels and bleeding risk
Decreased warfarin levels and increased clotting risk (Correct answer)
No significant change in warfarin levels
Increased risk of warfarin-induced hepatotoxicity

Correct answer: Decreased warfarin levels and increased clotting risk

St. John's Wort induces CYP2C9 and P-glycoprotein, which accelerates warfarin metabolism, reducing plasma levels and decreasing anticoagulant effect, increasing clotting risk.

St. John's Wort (Hypericum perforatum), commonly used for depression, is a potent inducer of CYP450 enzymes (particularly CYP2C9 and CYP3A4) and P-glycoprotein. Warfarin is primarily metabolized by CYP2C9. Enzyme induction increases warfarin metabolism, lowering plasma concentrations and decreasing INR. This subtherapeutic anticoagulation increases the risk of thromboembolic events such as stroke or PE. This interaction can be clinically significant within days of starting St. John's Wort. Nurses must ask patients about herbal supplements and advise against self-managing supplements while on warfarin without provider oversight.

Question 28: A patient prescribed metformin is scheduled for a CT scan with IV contrast. What is the nurse's priority action?

Hold the metformin on the day of the procedure and 48 hours after (Correct answer)
Administer metformin as usual and monitor blood glucose during the scan
Double the metformin dose to prevent contrast-induced hyperglycemia
Cancel the scan as contrast is absolutely contraindicated with metformin

Correct answer: Hold the metformin on the day of the procedure and 48 hours after

IV contrast can cause acute kidney injury, reducing metformin excretion and increasing the risk of lactic acidosis. Metformin is held before/on the day of contrast and resumed 48 hours after if kidney function is normal.

Metformin is renally excreted and does not cause lactic acidosis under normal circumstances. However, IV iodinated contrast can impair renal function (contrast-induced nephropathy). If kidneys fail to excrete metformin, it accumulates, potentially causing lactic acidosis — a serious, potentially fatal metabolic complication. Current guidelines recommend holding metformin at the time of contrast administration and for 48 hours afterward. Before restarting, renal function (serum creatinine/eGFR) should be confirmed to be stable. This is a standard pre-procedure protocol that the nurse should know and communicate to the patient.

Question 29: A patient with heart failure is prescribed torsemide. How does torsemide differ from hydrochlorothiazide?

Torsemide is a thiazide diuretic; hydrochlorothiazide is a loop diuretic
Torsemide is a loop diuretic with greater efficacy and better oral bioavailability in heart failure (Correct answer)
Torsemide retains potassium while hydrochlorothiazide wastes potassium
Torsemide is used only for hypertension, not fluid overload

Correct answer: Torsemide is a loop diuretic with greater efficacy and better oral bioavailability in heart failure

Torsemide is a loop diuretic that inhibits the Na-K-2Cl cotransporter in the loop of Henle. It has superior oral bioavailability (~80%) compared to furosemide and is more effective in patients with heart failure and gut edema.

Torsemide is a loop diuretic (inhibits Na-K-2Cl cotransporter in the ascending loop of Henle), providing powerful diuresis. In heart failure, gut edema can impair absorption of furosemide (which has variable oral bioavailability of 40–80%). Torsemide has more consistent oral bioavailability (~80%), longer duration of action, and comparable efficacy. It also has some aldosterone antagonist properties. Hydrochlorothiazide is a thiazide diuretic that acts in the distal convoluted tubule and has weaker diuretic effect—less effective for severe fluid overload. Both thiazides and loop diuretics waste potassium. Monitoring potassium and renal function is required with torsemide.

Question 30: A patient is started on ivabradine (Corlanor) for heart failure. Which baseline assessment is most important before administering this medication?

Blood pressure
Heart rate (Correct answer)
Respiratory rate
Oxygen saturation

Correct answer: Heart rate

Ivabradine specifically inhibits the If (funny) current in the SA node to reduce heart rate. It is indicated only for patients in sinus rhythm with resting HR ≥70 bpm; bradycardia is a contraindication.

Ivabradine (Corlanor) is a selective inhibitor of the hyperpolarization-activated cyclic nucleotide–gated (HCN) channel responsible for the cardiac pacemaker current (If) in the SA node. By reducing the rate of spontaneous SA node depolarization, it lowers heart rate without affecting contractility or blood pressure. It is indicated for HFrEF in patients with a resting HR ≥70 bpm on maximally tolerated beta-blocker doses, in normal sinus rhythm. Bradycardia (HR < 60) and sick sinus syndrome are contraindications. Visual disturbances (phosphenes/luminous phenomena) are a known side effect. Cardiac rhythm must be confirmed as sinus before use.

Question 31: The nurse is caring for a patient who overdosed on a calcium channel blocker. Which intervention is most appropriate for severe cardiovascular toxicity?

Administer IV magnesium sulfate
Administer IV calcium gluconate and high-dose insulin-euglycemic therapy (Correct answer)
Administer IV atropine as the first-line antidote
Administer IV sodium bicarbonate to reverse toxicity

Correct answer: Administer IV calcium gluconate and high-dose insulin-euglycemic therapy

Calcium channel blocker overdose is treated with IV calcium (restores channel function) and high-dose insulin therapy (improves myocardial glucose utilization and contractility), alongside vasopressors as needed.

Severe calcium channel blocker (CCB) overdose can cause life-threatening bradycardia, heart block, and cardiogenic shock. Management includes: (1) IV calcium chloride or gluconate to overcome the receptor blockade effect; (2) high-dose insulin-euglycemic therapy (HIET) — insulin at 1 unit/kg/hr IV with dextrose — improves cardiac contractility by shifting myocardial metabolism to glucose; (3) vasopressors (norepinephrine, epinephrine) for hypotension; (4) lipid emulsion therapy as rescue in severe refractory cases; (5) transcutaneous/transvenous pacing for bradycardia. Sodium bicarbonate is used for sodium channel blocker (tricyclic antidepressant) overdose. Atropine is often ineffective in severe CCB overdose.

Question 32: A nurse is preparing to administer IV labetalol for a hypertensive emergency. Which assessment is most important immediately after administration?

Blood glucose level
Blood pressure and heart rate every 5 minutes (Correct answer)
Serum potassium level
Temperature and respiratory rate

Correct answer: Blood pressure and heart rate every 5 minutes

IV labetalol rapidly lowers blood pressure and also blocks beta receptors causing bradycardia. Frequent BP and HR monitoring (every 5 minutes) is essential to prevent excessive hypotension or bradycardia.

IV labetalol is a combined alpha-1 and non-selective beta blocker used in hypertensive emergencies. It lowers both blood pressure and heart rate. After IV bolus or infusion initiation, the nurse must monitor BP and HR every 5 minutes because the drug can cause severe hypotension and bradycardia. The goal in hypertensive emergencies is controlled, gradual reduction of MAP by no more than 25% in the first hour to avoid ischemia. The patient should be in a supine position and connected to continuous cardiac monitoring. Excessive drops in BP can precipitate ischemic stroke, MI, or acute kidney injury.

Question 33: Which dietary recommendation should the nurse provide to a patient taking potassium-sparing diuretics?

Increase potassium-rich foods such as bananas and oranges
Avoid excess potassium-rich foods to prevent hyperkalemia (Correct answer)
Increase sodium intake to offset the sodium-wasting effect
Follow a high-protein diet to offset fluid losses

Correct answer: Avoid excess potassium-rich foods to prevent hyperkalemia

Potassium-sparing diuretics (spironolactone, triamterene, amiloride) retain potassium. Adding potassium-rich foods risks hyperkalemia, which can cause dangerous cardiac dysrhythmias.

Potassium-sparing diuretics — spironolactone (aldosterone antagonist), triamterene, and amiloride (ENaC blockers) — prevent potassium excretion in the distal nephron. Since these drugs already cause potassium retention, patients should avoid excessive dietary potassium to prevent hyperkalemia (K+ > 5.0 mEq/L). High-potassium foods include bananas, oranges, potatoes, avocados, and salt substitutes (which often contain potassium chloride). Hyperkalemia can cause muscle weakness, peaked T waves on ECG, and potentially fatal ventricular arrhythmias. The nurse should educate patients to read food labels and discuss diet with their provider.

Question 34: A patient newly prescribed enalapril asks why the provider chose this medication over another blood pressure drug. The nurse's best response is:

ACE inhibitors are the cheapest available antihypertensives
ACE inhibitors provide additional protection against kidney damage in diabetic patients (Correct answer)
ACE inhibitors are the only class safe to use in pregnancy
ACE inhibitors work best when combined with sodium-rich diets

Correct answer: ACE inhibitors provide additional protection against kidney damage in diabetic patients

ACE inhibitors reduce intraglomerular pressure by dilating the efferent arteriole. This provides renoprotective benefit in diabetic nephropathy by reducing proteinuria and slowing progression of kidney disease.

ACE inhibitors (e.g., enalapril, lisinopril) are preferred in patients with hypertension and diabetes because they reduce intraglomerular hypertension by preferentially dilating the efferent arteriole of the glomerulus. This decreases protein filtration (proteinuria) and slows progression to diabetic nephropathy. They are also beneficial in heart failure with reduced ejection fraction (HFrEF) and post-MI with reduced ejection fraction. They are NOT safe in pregnancy (teratogenic to fetal kidneys in 2nd/3rd trimester). ACE inhibitors should be taken on a low-sodium diet since sodium retention diminishes their antihypertensive effect.

Question 35: A patient on amiodarone therapy needs teaching about long-term monitoring. Which priority assessment should be included in teaching?

Monthly complete blood counts
Annual thyroid function tests, pulmonary function, and ophthalmologic exams (Correct answer)
Quarterly bone density scans
Weekly liver enzymes only

Correct answer: Annual thyroid function tests, pulmonary function, and ophthalmologic exams

Amiodarone contains iodine and has a very long half-life (40–55 days). It can cause thyroid dysfunction, pulmonary toxicity, hepatotoxicity, and corneal microdeposits, requiring multispecialty annual monitoring.

Amiodarone is approximately 37% iodine by weight and has an exceptionally long half-life of 40–55 days (tissue accumulation for months). Long-term toxicities include: (1) Thyroid: both hypothyroidism and hyperthyroidism (monitor TFTs every 6 months); (2) Pulmonary: interstitial pneumonitis/fibrosis (monitor with PFTs and chest X-ray annually); (3) Hepatic: elevated liver enzymes, hepatitis (monitor LFTs); (4) Ocular: corneal microdeposits in most patients, optic neuropathy (rare but serious — annual ophthalmologic exam); (5) Dermatologic: photosensitivity, blue-gray skin discoloration. Patients should use sunscreen and regular follow-up with multiple specialties is warranted.

NCLEX Pharmacology: Cardiovascular Medications 1

A patient is prescribed metoprolol succinate.
Which condition is this medication primarily used to treat?

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