Chapter 51: Diuretic Agents

After teaching a patient about the action of spironolactone, the nurse determines that the teaching was successful when the patient states:

"I need to make sure I don't eat too many high potassium foods." The drug is a potassium sparing diuretic placing the patient at risk for hyperkalemia, especially if the patient consumes foods high in potassium. The patient should take the medication in the morning to prevent interfering with sleep by having to get up at night to void. The patient can take the drug with meals if GI upset occurs. Many salt substitutes contain potassium, which could increase the patient's risk for hyperkalemia.

A male client has cirrhosis and is receiving diuretic therapy. The nurse knows that what drug will help prevent metabolic alkalosis or hypokalemia in this client?

Spironolactone For clients with cirrhosis, diuretic therapy should be initiated in a hospital setting, with small doses and careful monitoring. To prevent hypokalemia and metabolic alkalosis, supplemental potassium or spironolactone may be needed.

The health care provider indicates that a client experiencing renal failure is not a candidate for therapy with potassium-sparing diuretics. How will the nurse respond when the client's family member asks why this is the case?

They may cause hyperkalemia. Potassium-sparing diuretics accumulate in renal insufficiency and present the risk for hyperkalemia. For this reason, health care practitioners typically avoid the drug in this population. Potassium-sparing diuretics decrease potassium excretion, and, by themselves, they are weak diuretics. Rebound edema may be a concern when a diuretic is discontinued, but it is not the reason this client is a poor candidate for a potassium-sparing diuretic.

A 49-year-old client reports frequent muscle cramps while on hydrochlorothiazide therapy. The nurse would advise the client to do which?

eat potassium-rich foods. The client is most likely experiencing muscle cramps due to potassium loss. Therefore, the nurse should advise the client to include potassium supplements in the diet. Drinking plenty of fluids or using calcium supplements will not reduce the occurrence of cramps. It is important to caution the client to avoid foods high in sodium because they could counteract the effects of drug therapy.

Which instruction would be most appropriate for a client who is taking a diuretic?

"It's okay to take it with food." Instructions for a client taking a diuretic include taking the drug with food or meals if gastrointestinal upset occurs, taking the dose early in the morning to prevent interfering with sleep, implementing safety precautions if dizziness or weakness is a problem, and ensuring adequate fluid intake to prevent fluid rebound. It is not necessary to lie down after taking the drug.

The health care provider orders furosemide for a pediatric client. The nurse knows that the established dose of the drug should not exceed how many milligrams per kilogram of body weight per day?

6 Furosemide is the loop diuretic used most often in children. Oral therapy is preferred when feasible, and doses greater than 6 mg/kg of body weight per day are not recommended.

A nurse demonstrates understanding of diuretics when identifying which medication as exerting its effect by inhibiting the enzyme carbonic anhydrase?

Acetazolamide Acetazolamide is a carbonic anhydrase inhibitor that exerts its effect by inhibiting the enzyme carbonic anhydrase. Furosemide is a loop diuretic. Hydrochlorothiazide is a thiazide diuretic. Spironolactone is a potassium-sparing diuretic.

After teaching a group of nursing students about diuretics, the instructor determines that the teaching was successful when the group identifies which as a loop diuretic?

Furosemide Furosemide (Lasix) is an example of a loop diuretic. Hydrochlorothiazide is a thiazide diuretic. Acetazolamide is a carbonic anhydrase inhibitor. Spironolactone is a potassium-sparing diuretic.

An older adult client has a complex medical history that includes heart failure, type 1 diabetes, and diabetic nephropathy. The nurse has questioned a health care provider's prescription for oral spironolactone because the client's health problems would contribute to a high risk of which adverse reaction?

Hyperkalemia The presence of renal insufficiency is also a contraindication to the use of spironolactone because use of spironolactone may cause hyperkalemia through the inhibition of aldosterone and the subsequent retention of potassium. A prescription for spironolactone does not put this client at a greatly increased risk of anemia, hypocalcemia, or acidosis since none of these conditions are associated with potassium.

A client is unconscious and experiencing increasing intracranial pressure. What type of diuretic will the client most likely be prescribed?

Osmotic diuretic An osmotic diuretic is used to reduce intracranial pressure related to a head injury. Loop diuretics, potassium-sparing diuretics, and thiazide diuretics do not reduce intracranial pressure.

A health care provider prescribes spironolactone, a potassium-sparing diuretic, for a client with cirrhosis. For which category of clients is the use of potassium-sparing diuretics contraindicated?

hyperkalemia The nurse should know that potassium-sparing diuretics are contraindicated in clients with hyperkalemia and are not recommended for children. Potassium-sparing diuretics should be used cautiously in clients with liver disease, diabetes, or gout, but presence of these conditions does not contraindicate the use of potassium diuretics.

A health care provider has prescribed triamterene to a male client with renal disease. The client informs the nurse that he is taking potassium supplements to address some heart problems. The nurse would be alert for:

increased risk of hyperkalemia. The nurse should inform the client about the increased risk of hyperkalemia as the effect of the interaction between triamterene, which is a potassium-sparing diuretic, and potassium supplements. When the client is administered loop diuretics with anticoagulants or thrombolytics, there will be increased risk of bleeding. When the client is administered digitalis with loop diuretics, there is an increased risk of arrhythmias. Decreased diuretic effect, in this case decreased effect of triamterene, will occur when a potassium-sparing diuretic such as triamterene is administered with NSAIDs, salicylates, and anticoagulants.

A patient with a longstanding diagnosis of chronic renal failure has experienced a significant decline in urine output in recent days, prompting him to seek care at a local clinic. A nurse at the clinic has suggested to a colleague that the administration of a diuretic such as hydrochlorothiazide may improve the patient's urine output. How should the colleague best respond to this suggestion?

"Actually, patients with renal failure usually can't take hydrochlorothiazide." Renal disease and severe renal impairment contraindicate the use of hydrochlorothiazide. HCTZ affects the kidneys, not the bladder, and is not administered intravenously.

When describing where bumetanide acts, what would the nurse include?

Loop of Henle Bumetanide is a loop diuretic that blocks the chloride pump in the ascending loop of Henle. It also has a similar effect in the descending loop and in the distal convoluted tubule.

A client is diagnosed with increased intracranial pressure. Which would the nurse expect to be ordered?

Mannitol Mannitol is a powerful osmotic diuretic that is used to treat increased intracranial pressure. It is given intravenously and begins to work in 30 to 60 minutes. Furosemide, amiloride, and bumetanide are not indicated for the treatment of increased intracranial pressure.

The nurse is caring for a client who is experiencing elevated intracranial pressure following neurosurgery. The health care provider orders an osmotic diuretic to reduce pressure. Which medication would the nurse expect to be ordered?

Mannitol Mannitol is an osmotic diuretic used frequently in cases of increased ICP. Bumetanide and ethacrynic acid are loop diuretics, and spironolactone is a potassium-sparing diuretic.

What would contraindicate the use of indapamide?

Renal disease Indapamide would be contraindicated in a client with severe renal disease, which may prevent the diuretic from working or precipitate a crisis stage due to blood flow changes brought about by the diuretic. Indapamide would be used cautiously in clients with diabetes, systemic lupus erythematosus, or gout.

A client asks, "Why is my prescription being switched from furosemide to spironolactone?" What is the nurse's best response?

"You will lose less potassium with spironolactone than with furosemide." By inhibiting the effects of aldosterone in the distal tubules, spironolactone promotes potassium retention. The client will not have greater potassium losses, water losses, or sodium losses with spironolactone rather than furosemide.

A patient receives furosemide intravenously at 9 AM. The nurse would expect to assess peak effects of the drug at which time?

9:30 AM Furosemide, when given IV, peaks in 30 minutes; the nurse would see peak drug action at approximately 9:30 AM.

A nurse is caring for a client with acute renal failure. The health care provider has prescribed a diuretic therapy for the client to promote dieresis. What intervention should the nurse perform to prevent the inconvenience caused by increased urination?

Administer the drug early in the day. The nurse should administer the drug early in the day to prevent any nighttime sleep disturbance caused by increased urination when caring for a client receiving a diuretic therapy for acute renal failure. The nurse need not ask the client to decrease fluid intake, gradually increase the drug dosage, or encourage the client to exercise as these are not appropriate interventions and will not help in reducing the discomfort caused by increased urination.

After teaching a group of students about loop diuretics, the instructor determines that the teaching has been successful when the students identify which agent as the safest for use in the home?

Furosemide Furosemide is less powerful than bumetanide and torsemide and therefore has a larger margin of safety for home use (see the Critical Thinking Scenario in this chapter for additional information about using furosemide in heart failure). Ethacrynic acid is used less frequently in the clinical setting because of the improved potency and reliability of the newer drugs.

A client is admitted to the emergency department with pulmonary edema. What diuretic does the nurse expect the health care provider to prescribe to achieve rapid therapeutic effect?

Loop diuretic Loop diuretics are the diuretics of choice when rapid effects are required, such as in the treatment of pulmonary edema. The health care provider is, therefore, less likely to prescribe one of the other medications at this time.