A patient with a documented severe reaction to sulfonamide drugs needs a loop diuretic. Which drug lacks a sulfonamide structure?
Ethacrynic acid
✓
Furosemide
Bumetanide
Torsemide
Correct Answer
Ethacrynic acid
Ethacrynic acid is the loop diuretic without a sulfonamide group, so it is the usual option when a true sulfonamide allergy rules out the others; it carries a notable risk of ototoxicity. Furosemide is a sulfonamide derivative. Bumetanide is also a sulfonamide derivative. Torsemide contains a sulfonylurea group and is contraindicated in sulfonylurea hypersensitivity.
Category: Loop Diuretics
Question 2
A patient with heart failure no longer responds to high doses of a loop diuretic. Which thiazide-like drug is often added so that sodium reabsorption is also blocked further along the nephron?
Mannitol
Metolazone
✓
Amiloride
Acetazolamide
Correct Answer
Metolazone
Metolazone blocks sodium reabsorption in the distal tubule, so adding it to a loop diuretic can overcome diuretic resistance; the combination can cause profound fluid and electrolyte loss and needs close monitoring. Mannitol is an osmotic diuretic used mainly for intracranial and intraocular pressure. Amiloride is a weak potassium-sparing diuretic, not a thiazide-like drug. Acetazolamide is a weak carbonic anhydrase inhibitor diuretic.
Category: Thiazide Diuretics
Question 3
Which teaching addresses a skin-related adverse effect of hydrochlorothiazide?
Apply a moisturizer after every bath
Avoid wearing wool clothing
Use sunscreen and limit sun exposure
✓
Bathe only in cool water
Correct Answer
Use sunscreen and limit sun exposure
Thiazide diuretics can cause photosensitivity reactions, so patients protect their skin with sunscreen, covering clothing and limited time in strong sun, and report rashes. Apply a moisturizer after every bath helps dry skin but does not address photosensitivity. Avoid wearing wool clothing is advice for eczema-prone skin. Bathe only in cool water has no link to thiazide adverse effects.
Category: Thiazide Diuretics
Question 4
An older adult taking hydrochlorothiazide who drinks large amounts of water becomes confused, nauseated and lethargic. Which laboratory result should the nurse check first?
Serum uric acid
Serum amylase
Serum albumin
Serum sodium
✓
Correct Answer
Serum sodium
Thiazides block sodium reabsorption and can cause hyponatremia, especially in older adults with a high water intake, and falling sodium causes nausea, confusion, lethargy and eventually seizures. Serum uric acid rises with thiazides but causes gout rather than confusion. Serum amylase is checked for pancreatitis, which presents with abdominal pain. Serum albumin reflects nutrition and liver function and does not explain these acute symptoms.
Category: Thiazide Diuretics
Question 5
Taking which drug together with hydrochlorothiazide adds to the risk of hypokalemia?
Prednisone
✓
Spironolactone
Amiloride
Lisinopril
Correct Answer
Prednisone
Corticosteroids such as prednisone increase potassium loss in the urine, so combining them with a thiazide intensifies electrolyte depletion. Spironolactone conserves potassium and offsets thiazide-induced loss. Amiloride also conserves potassium. Lisinopril lowers aldosterone and tends to raise potassium.
Category: Thiazide Diuretics
Question 6
Which over-the-counter drug should a patient taking spironolactone avoid unless the provider approves it, because it can raise serum potassium and weaken the diuretic effect?
Acetaminophen
Ibuprofen
✓
Loratadine
Docusate
Correct Answer
Ibuprofen
NSAIDs such as ibuprofen reduce kidney prostaglandins, which lowers potassium excretion and blunts diuresis, so together with spironolactone they raise the risk of hyperkalemia and kidney injury. Acetaminophen does not share these kidney effects. Loratadine is a nonsedating antihistamine without this interaction. Docusate is a stool softener without this interaction.
Category: Potassium-Sparing Diuretics
Question 7
A man taking spironolactone for heart failure reports tender swelling of both breasts. What should the nurse recognize?
Fluid retention from worsening heart failure
An allergic reaction to the drug
Gynecomastia, a known adverse effect of the drug
✓
A sign of low serum potassium
Correct Answer
Gynecomastia, a known adverse effect of the drug
Spironolactone blocks androgen receptors as well as aldosterone receptors, so it can cause gynecomastia, tender enlargement of male breast tissue; the nurse reports it, and the provider may switch to a more selective aldosterone blocker. Fluid retention from heart failure shows as weight gain, edema of dependent areas and crackles, not breast tenderness. An allergic reaction presents with rash, hives or swelling of the face and airway. Low serum potassium is not expected with spironolactone, which tends to raise potassium, and it does not cause breast changes.
Category: Potassium-Sparing Diuretics
Question 8
How does amiloride conserve potassium?
It blocks aldosterone receptors
It inhibits carbonic anhydrase
It blocks the loop's sodium-potassium-chloride carrier
It blocks sodium channels in the collecting tubule
✓
Correct Answer
It blocks sodium channels in the collecting tubule
Amiloride, like triamterene, directly blocks epithelial sodium channels in the late distal and collecting tubule, so less sodium enters the cells and less potassium is secreted in exchange. It blocks aldosterone receptors describes spironolactone and eplerenone. It inhibits carbonic anhydrase describes acetazolamide. It blocks the loop's sodium-potassium-chloride carrier describes loop diuretics, which increase potassium loss.
Category: Potassium-Sparing Diuretics
Question 9
Before infusing mannitol, the nurse sees crystals in the vial. What should the nurse do?
Warm the vial to dissolve the crystals before use
✓
Refrigerate the vial until the crystals clear
Give the drug, since crystals are harmless
Dilute the drug with sterile water first
Correct Answer
Warm the vial to dissolve the crystals before use
Mannitol can crystallize when cool; warming and shaking the vial dissolves the crystals, the solution is then allowed to cool before use, and it is discarded if crystals remain. Refrigerate the vial until the crystals clear would make crystallization worse. Give the drug, since crystals are harmless is unsafe because infused crystals can damage vessels and organs. Dilute the drug with sterile water first does not dissolve crystals and is not how mannitol is prepared.
Category: Osmotic Diuretics
Question 10
A patient taking acetazolamide has a low serum bicarbonate level. Which respiratory change shows the body compensating for it?
Slow, shallow breathing
Faster, deeper breathing
✓
Long pauses between breaths
Wheezing on exhalation
Correct Answer
Faster, deeper breathing
Acetazolamide makes the kidneys lose bicarbonate, producing metabolic acidosis, and the lungs compensate by breathing faster and deeper to blow off carbon dioxide. Slow, shallow breathing retains carbon dioxide, the lungs' response to alkalosis rather than acidosis. Long pauses between breaths do not compensate for acidosis and suggest a problem with respiratory control. Wheezing on exhalation reflects narrowed airways, not acid-base compensation.
Category: Carbonic Anhydrase Inhibitors
Question 11
Hydrochlorothiazide is often combined with triamterene in a single product. What does the triamterene add?
It prevents sulfonamide allergy
It lowers blood glucose
It reduces potassium loss
✓
It prevents uric acid buildup
Correct Answer
It reduces potassium loss
Triamterene is a potassium-sparing diuretic that offsets the potassium wasting caused by the thiazide, though the combination can still cause hyperkalemia, especially with kidney impairment or diabetes. It prevents sulfonamide allergy is wrong because hydrochlorothiazide remains a sulfonamide. It lowers blood glucose is wrong because triamterene has no glucose-lowering action. It prevents uric acid buildup is wrong because triamterene does not reverse the thiazide rise in uric acid.
Category: Potassium-Sparing Diuretics
Question 12
Which daily weight instruction gives a patient taking a diuretic the most reliable picture of fluid change?
After breakfast, on any available scale
At bedtime, wearing street clothes
Only on days the ankles look swollen
Same time, same scale, similar clothing
✓
Correct Answer
Same time, same scale, similar clothing
Weighing under identical conditions, usually in the morning after voiding, makes day-to-day changes reflect fluid rather than food, clothing or a different scale, and a rapid gain is reported. After breakfast, on any available scale adds food weight and scale error. At bedtime, wearing street clothes adds the day's intake and clothing weight. Only on days the ankles look swollen misses fluid gain before edema becomes visible.
Category: Diuretic Nursing Care
Question 13
Which findings in a patient receiving furosemide suggest excessive fluid loss?
Dizziness on standing and dry mucous membranes
✓
Crackles and neck vein distention
Weight gain and ankle edema
Bounding pulse and high blood pressure
Correct Answer
Dizziness on standing and dry mucous membranes
Overdiuresis lowers blood volume, which causes orthostatic dizziness, thirst, dry mucous membranes and poor skin turgor, and the nurse holds further doses and notifies the provider. Crackles and neck vein distention point to fluid overload. Weight gain and ankle edema also point to fluid overload. Bounding pulse and high blood pressure reflect excess volume, not deficit.
Category: Loop Diuretics
Question 14
Why are patients taking loop diuretics taught to avoid alcohol?
It blocks absorption of the diuretic
It worsens the drop in blood pressure on standing
✓
It raises serum potassium levels
It makes the drug crystallize in urine
Correct Answer
It worsens the drop in blood pressure on standing
Alcohol dilates blood vessels and adds to diuretic-induced orthostatic hypotension, increasing the risk of dizziness and falls. It blocks absorption of the diuretic is not a recognized effect of alcohol. It raises serum potassium levels is wrong because alcohol does not offset diuretic potassium loss in this way. It makes the drug crystallize in urine is not a loop diuretic concern.
Category: Loop Diuretics
Question 15
In which part of the nephron does acetazolamide mainly act?
Thick ascending limb
Distal convoluted tubule
Proximal convoluted tubule
✓
Collecting duct
Correct Answer
Proximal convoluted tubule
Carbonic anhydrase in the proximal tubule is needed to reclaim filtered bicarbonate, so inhibiting it leaves sodium bicarbonate and water in the tubule. Thick ascending limb is where loop diuretics act. Distal convoluted tubule is where thiazides act. Collecting duct is where potassium-sparing diuretics act.
Category: Carbonic Anhydrase Inhibitors
Question 16
Which patient taking amiloride has the greatest risk of hyperkalemia?
A young adult with normal kidney function
A patient who also takes furosemide
A patient recovering from repeated vomiting
A patient with diabetes and impaired kidney function
✓
Correct Answer
A patient with diabetes and impaired kidney function
Amiloride and triamterene carry a boxed warning for hyperkalemia, and the risk is highest with kidney impairment, diabetes and older age, or when other potassium-raising drugs are added. A young adult with normal kidney function clears potassium well. A patient who also takes furosemide has a loop diuretic that increases potassium loss. A patient recovering from repeated vomiting tends to lose potassium.
Category: Potassium-Sparing Diuretics
Question 17
During mannitol therapy, which laboratory value is monitored along with electrolytes and kidney function to guide treatment?
Serum osmolarity
✓
Serum amylase
Prothrombin time
Hemoglobin A1C
Correct Answer
Serum osmolarity
Mannitol works by raising the osmotic pressure of plasma, so serum osmolarity, fluid balance, electrolytes and renal, cardiac and pulmonary status are monitored and the drug is adjusted or stopped if values climb too high. Serum amylase is used to assess the pancreas. Prothrombin time measures clotting and warfarin effect. Hemoglobin A1C reflects long-term glucose control.
Category: Osmotic Diuretics
Question 18
A rebound rise in intracranial pressure after mannitol is more likely in which patient?
One who has normal kidney function
One whose blood-brain barrier is damaged
✓
One who receives the drug through a filter
One whose serum sodium is normal
Correct Answer
One whose blood-brain barrier is damaged
When the blood-brain barrier is disrupted, mannitol can pass into brain tissue and later draw water back in, so pressure may climb again after the infusion ends. One who has normal kidney function excretes mannitol efficiently. One who receives the drug through a filter is receiving it as directed, which prevents crystal infusion. One whose serum sodium is normal has no added rebound risk from that value.
Category: Osmotic Diuretics
Question 19
Which food should a patient taking furosemide avoid because it adds to the drug's potassium loss?
Bananas
Plain yogurt
Black licorice
✓
Fresh spinach
Correct Answer
Black licorice
Real black licorice contains glycyrrhizin, which acts like aldosterone and increases potassium loss in the urine, so with a loop diuretic it raises the risk of hypokalemia; patients are taught to avoid it. Bananas, plain yogurt and fresh spinach are potassium-rich foods that help offset the potassium a loop diuretic removes.
Category: Loop Diuretics
Question 20
A patient who takes furosemide and digoxin reports nausea and yellow-green halos around lights. Which laboratory result would best explain these symptoms?
High serum sodium
Low serum calcium
High blood glucose
Low serum potassium
✓
Correct Answer
Low serum potassium
Loop diuretics wash potassium out in the urine, and low potassium lets digoxin act more strongly on the sodium-potassium pump, so toxicity with nausea and visual changes can appear; the nurse checks potassium and the digoxin level and notifies the provider. High serum sodium does not increase digoxin effect. Low serum calcium does not raise the risk of digoxin toxicity; high calcium is the level that adds to it. High blood glucose does not alter digoxin action.
Category: Diuretic Nursing Care