“Metoprolol.”

✅ Metoprolol slows the sinus rate and decreases AV nodal conduction, which helps reduce the ventricular rate in rapid atrial fibrillation.

✅ In atrial fibrillation with a fast ventricular response, rate control is often achieved with medications that slow conduction through the AV node.

✅ Metoprolol is a beta blocker, so it is effective for lowering heart rate when the client is hemodynamically stable.

✅ By reducing the ventricular response, it can improve symptoms such as palpitations, dyspnea, and decreased cardiac output.

✅ This makes metoprolol an appropriate medication for rapid atrial fibrillation with HR 150/min.

“Verapamil.”

✅ Verapamil is a non-dihydropyridine calcium channel blocker that decreases heart rate and slows AV nodal conduction.

✅ It also has vasodilatory effects by lowering systemic vascular resistance, but its key role here is rate control.

✅ In rapid atrial fibrillation, verapamil can help slow the ventricular response and improve hemodynamic tolerance.

✅ This drug is especially useful when the clinical goal is to control rate rather than immediately cardiovert the rhythm.

✅ Therefore, verapamil is a correct option for reducing heart rate in this client.

“Diltiazem.”

✅ Diltiazem decreases vascular resistance and produces a slight decrease or no change in resting heart rate chronically, while IV diltiazem prolongs AV nodal conduction and is effective for rapid supraventricular rhythms.

✅ The FDA labeling notes that diltiazem can reduce heart rate and slow AV nodal conduction, which is exactly what is needed in rapid atrial fibrillation.

✅ It is a common medication used to control the ventricular response when the atria are fibrillating rapidly.

✅ By slowing AV conduction, it helps prevent the ventricles from responding to every chaotic atrial impulse.

✅ For that reason, diltiazem is also a correct medication choice in this question.

“Nitroglycerin.”

✅ Nitroglycerin is a vasodilator used for angina and does not treat atrial fibrillation by slowing AV nodal conduction.

✅ It may reduce chest pain, but it will not reliably correct the arrhythmia or control the ventricular rate.

“Prazosin.”

✅ Prazosin is an alpha-1 blocker used mainly for hypertension and does not manage rapid atrial fibrillation.

✅ It can lower blood pressure, but it does not provide the AV nodal slowing needed for this rhythm.

🌟 Spironolactone is a potassium-sparing diuretic, so the priority safety concern is hyperkalemia.

🌟 The FDA labeling specifically recommends monitoring serum potassium within one week of initiation and regularly thereafter.

🌟 Clients with heart failure often take other medications that can also raise potassium, increasing the risk of dangerous dysrhythmias.

🌟 Because elevated potassium can become life-threatening, potassium monitoring is more important than routine teaching about timing of the dose.

🌟 For this reason, the priority intervention is to regularly check serum potassium.

“Educate to administer at bedtime.”

🌟 Diuretics are usually better taken earlier in the day to reduce nocturia rather than at bedtime.

🌟 This teaching is not the priority compared with preventing hyperkalemia.

“Monitor the urine specific gravity.”

🌟 Urine specific gravity can provide hydration information, but it is not the main safety issue with spironolactone therapy.

🌟 The greater concern is the drug’s effect on potassium retention.

“Encourage a potassium rich diet.”

🌟 A potassium-rich diet can worsen hyperkalemia in a client taking spironolactone.

🌟 This instruction would be unsafe rather than therapeutic.

💠 Niacin commonly causes flushing, including warmth, redness, itching, and tingling of the skin.

💠 FDA labeling identifies flushing as one of the most common adverse effects and notes that it often decreases after several weeks of consistent therapy.

💠 Teaching the client about this effect beforehand helps reduce anxiety and improves adherence to therapy.

💠 Clients are often told to avoid hot drinks or alcohol near the time of dosing because these can worsen the flushing response.

💠 Therefore, the most important teaching here is that niacin often causes facial flushing.

“This medication can cause vitamin D deficiency.”

💠 Niacin is not known for causing vitamin D deficiency as a standard teaching point.

💠 The hallmark counseling issue is flushing, not vitamin depletion.

“This medication is also known as vitamin 89.”

💠 Niacin is also known as vitamin B3, not “vitamin 89.”

💠 This statement is factually incorrect and should not be taught.

“This medication can discolor your urine.”

💠 Urine discoloration is not the classic teaching point associated with niacin.

💠 The major expected adverse effect is flushing of the face and upper body.

🟣 Ezetimibe lowers cholesterol by inhibiting the absorption of cholesterol in the small intestine.

🟣 It acts at the brush border of the small intestine and decreases delivery of intestinal cholesterol to the liver.

🟣 This reduces hepatic cholesterol stores and helps increase clearance of cholesterol from the blood.

🟣 Its mechanism is different from statins, which reduce cholesterol synthesis rather than intestinal absorption.

🟣 For this reason, the correct explanation is that ezetimibe inhibits cholesterol absorption in the GI tract.

“Inhibits the synthesis of cholesterol in the liver.”

🟣 This describes the mechanism of statins, not ezetimibe.

🟣 Ezetimibe works in the intestine, not by blocking hepatic cholesterol synthesis.

“Increases the excretion of cholesterol in the gallbladder.”

🟣 Ezetimibe does not primarily work by pushing cholesterol out through the gallbladder.

🟣 Its main action is reducing intestinal uptake of cholesterol.

“Increases the conversion of LDL to HDL cholesterol.”

🟣 Ezetimibe does not convert LDL into HDL.

🟣 It lowers LDL mainly by reducing the amount of cholesterol absorbed from the gut.

Diltiazem

🔷 Diltiazem decreases vascular resistance and also slows AV nodal conduction, which can reduce heart rate.

🔷 This combination makes it different from the dihydropyridine calcium channel blockers that mainly act on blood vessels.

🔷 Because it provides both vasodilation and rate-slowing effects, diltiazem fits both parts of the question.

🔷 Its AV nodal action is why it is often used for rate control in certain supraventricular arrhythmias.

🔷 Therefore, diltiazem is a correct answer.

Verapamil.

🔷 Verapamil lowers systemic vascular resistance, showing its vasodilatory effect on blood vessels.

🔷 It also slows AV nodal conduction and decreases heart rate, which makes it useful in rate control.

🔷 This means verapamil affects both the vasculature and the cardiac conduction system.

🔷 That profile is characteristic of the non-dihydropyridine calcium channel blockers.

🔷 For that reason, verapamil is also correct.

Felodipine.

🔷 Felodipine is a dihydropyridine calcium channel blocker that mainly causes vasodilation.

🔷 It does not significantly reduce heart rate the way diltiazem and verapamil do.

Nifedipine.

🔷 Nifedipine mainly acts on vascular smooth muscle and is more associated with vasodilation than AV nodal slowing.

🔷 It is not the best answer when the question asks for both vasodilation and reduced heart rate.

Amlodipine.

🔷 Amlodipine is also a dihydropyridine calcium channel blocker with predominant vasodilatory effects.

🔷 It does not reliably produce the heart-rate lowering effect seen with diltiazem and verapamil.

🟡 Dimercaprol is indicated for poisoning with arsenic, gold, and mercury.

🟡 FDA labeling specifically states that it is effective in acute mercury poisoning, especially if therapy begins early.

🟡 Dimercaprol works as a chelating agent, binding certain heavy metals so they can be removed from the body.

🟡 Because mercury is a heavy metal and listed directly in the drug indication, it is the correct answer here.

🟡 This makes mercury poisoning the most appropriate condition to treat with dimercaprol.

Diazepam.

🟡 Diazepam overdose is not treated with dimercaprol because diazepam is not a heavy metal.

🟡 Benzodiazepine toxicity is managed differently, often with supportive care and sometimes flumazenil in selected cases.

Digoxin.

🟡 Digoxin toxicity is not treated with dimercaprol.

🟡 The specific antidote for serious digoxin toxicity is digoxin immune Fab, not a heavy-metal chelator.

Morphine.

🟡 Morphine overdose is an opioid poisoning, not a heavy-metal poisoning.

🟡 The reversal agent for opioid toxicity is naloxone, not dimercaprol.

🟤 Procainamide is an antiarrhythmic, so the clearest sign that it is working is restoration of normal sinus rhythm on the ECG.

🟤 The FDA source specifically references its use in conversion of atrial fibrillation to normal sinus rhythm.

🟤 A therapeutic response should reflect improvement in the dysrhythmia itself, not just a secondary value like blood pressure.

🟤 Because the drug is being infused to manage an arrhythmia, ECG evidence of sinus rhythm is the most direct indicator of effectiveness.

🟤 Therefore, the therapeutic finding is that the ECG shows normal sinus rhythm.

“The client's peripheral edema has reduced in severity.”

🟤 Reduced edema would suggest improvement in fluid balance, not direct correction of an arrhythmia.

🟤 Procainamide is not being given to treat peripheral edema.

“The client's total cholesterol is within the normal range.”

🟤 Cholesterol levels are unrelated to whether procainamide is correcting an acute dysrhythmia.

🟤 This finding does not evaluate antiarrhythmic effectiveness.

“The client's blood pressure is within the normal range.”

🟤 A normal blood pressure can be helpful, but it does not prove the arrhythmia has resolved.

🟤 The best therapeutic evidence is ECG confirmation of normal sinus rhythm.

“Dizziness and orthostatic hypotension.”

🌈 IV furosemide can cause orthostatic hypotension because it promotes rapid diuresis and intravascular volume loss.

🌈 The FDA labeling lists orthostatic hypotension among cardiovascular adverse reactions and dizziness among central nervous system reactions.

🌈 These effects are especially important after IV administration, when diuresis and blood pressure changes may occur more quickly.

🌈 Clients may become lightheaded when standing because their circulating volume has decreased.

🌈 For this reason, dizziness and orthostatic hypotension are correct adverse effects of IV furosemide.

“Onset of tinnitus and hearing loss.”

🌈 Furosemide can cause ototoxicity, including tinnitus and hearing loss, especially with rapid injection or high doses.

🌈 The FDA labeling specifically warns that tinnitus and reversible or irreversible hearing impairment have been reported.

🌈 This adverse effect is more likely in clients with renal impairment or when other ototoxic drugs are also being used.

🌈 Because the question asks about IV administration, this is especially relevant since rapid IV dosing raises the risk.

🌈 Therefore, tinnitus and hearing loss are also correct answers.

“Increased appetite and weight gain.”

🌈 Furosemide is a loop diuretic, so it more commonly causes fluid loss, not weight gain from increased appetite.

🌈 This statement does not match the expected adverse-effect profile of IV furosemide.

“Hyperkalemia and volume overload.”

🌈 Furosemide typically causes hypokalemia, not hyperkalemia, and it is used to treat fluid overload, not cause it.

🌈 This option reverses the expected pharmacologic effects of the medication.

“Muscle spasms due to hypernatremia.”

🌈 Furosemide can contribute to electrolyte loss, but hypernatremia is not the classic adverse effect named here.

🌈 The more expected concern is volume depletion and losses such as hypokalemia, not hypernatremia-driven spasms in this form.