Pharmacology - Prep U - Chapter 51

A patient is receiving acetazolamide in a sustained release form. The nurse would anticipate the onset of drug action in approximately which time frame?

2 hours Acetazolamide in sustained release form has an onset of action of 2 hours.

A client is receiving hydrochlorothiazide. The nurse would expect this drug to begin acting within which time frame?

2 hours Hydrochlorothiazide has an onset of action of 2 hours, peaking in 4 to 6 hours, and lasting approximately 6 to 12 hours.

The nurse should be aware that diuresis will peak how long after furosemide is administered?

30 minutes After IV administration, diuretic effects of furosemide occur within 5 minutes, peak within 30 minutes, and last about 2 hours.

A client receives a dose of furosemide intravenously at 8:00 AM. The nurse would expect this drug to exert is peak effects at which time?

8:30 AM Furosemide, when given intravenously, begins to act in 5 minutes, reaching peak effects in 30 minutes. In this case, this would be 8:30 AM.

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 client has edema of the lower extremities and abdomen. What is the reason to administer a stronger diuretic than a thiazide diuretic to this client?

A thiazide diuretic will be ineffective when immediate diuresis is needed. Thiazide diuretics are ineffective when immediate diuresis is required. A thiazide diuretic acts to reabsorb sodium, not potassium, in the distal convoluted tubule. A thiazide diuretic reaches its peak in 4 to 6 hours. A thiazide diuretic is excreted in 72 hours maximum.

A nurse is providing patient teaching for a 62-year-old woman who is taking triamterene. The nurse will teach the patient to avoid what in her diet?

Avocados

When describing the action of spironolactone, the nurse would explain that this drug acts by:

Blocking aldosterone in the distal tubule Spironolactone acts as an aldosterone antagonist blocking the actions of aldosterone in the distal tubule. Amiloride and triamterene block potassium secretion through the tubule. Carbonic anhydrase inhibitors slow the movement of hydrogen ions. Loop diuretics block the chloride pump.

Diuretics increase the production and output of urine. Which statement helps explain how diuretics achieve these effects?

Diuretics reduce the reabsorption of water in the kidneys. Diuretics increase urine production and output by reducing the reabsorption of water and electrolytes in the kidneys.

What type of diet should a patient taking diuretics have?

Eat potassium-rich or low-potassium diet as appropriate Provide potassium-rich or low-potassium diet as appropriate to maintain electrolyte balance and replace lost potassium or prevent hyperkalemia.

An elderly patient with a history of congestive heart failure has been admitted to hospital with failure to thrive and admission blood work reveals a hemoglobin level of 6.9 g/dL. The care team has consequently administered two units of packed red blood cells, but auscultation of the client's lungs now reveals diffuse crackles. Administration of what drug is likely to resolve the patient's pulmonary edema?

Furosemide Furosemide can be given intravenously to provide rapid relief from pulmonary edema. Mannitol is not normally used to treat pulmonary edema and neither HCTZ nor triamterene is used in the acute treatment of pulmonary edema.

A male client has cirrhosis of the liver that has caused ascites. The nurse knows that what condition may occur if diuretics are used to reduce the ascites?

Hepatic encephalopathy Diuretics are often used to manage edema and ascites in clients with hepatic impairment. These drugs must be used with caution, because diuretic-induced fluid and electrolyte imbalances may precipitate or worsen hepatic encephalopathy and coma.

A male client is prescribed potassium-sparing diuretics to treat his disease process. During his annual visit to the health care provider, he reports experiencing muscle weakness and tingling in his fingers. What does the nurse suspect is wrong with this client?

Hyperkalemia Potassium-sparing diuretics are contraindicated in clients with renal impairment because of the high risk of hyperkalemia.

A client who has been taking hydrochlorothiazide arrives at the clinic for his 1-month follow-up appointment. The client tells the nurse that he feels weaker since he began taking the drug. What should the nurse consider as a possible cause of these symptoms?

Hypokalemia Thiazides, such as hydrochlorothiazide, are potassium-losing diuretics, and their use can lead to hypokalemia. Symptoms of hypokalemia include muscle weakness, dysrhythmia, hypotension, anorexia, and and shallow respirations.

A health care provider has prescribed a loop diuretic for a client with hypertension. The client also has diabetes mellitus. What condition should the nurse monitor for in this client after administering the prescribed drug?

Increased blood glucose levels The nurse should monitor for increased blood glucose levels in the diabetic client receiving a loop diuretic. The blood glucometer test results for these clients may be elevated, or urine may test positive for glucose. Thiazide diuretic agents may cause gout attacks and sudden joint pain. The nurse need not monitor for a sudden increase in weight as the administration of loop diuretics to a diabetic client will not cause this effect.

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.

Which would the nurse expect to find in a client receiving acetazolamide?

Metabolic acidosis Metabolic acidosis is a relatively common and potentially dangerous effect that occurs when bicarbonate is lost due to the action of carbonic anhydrase inhibitors. Metabolic alkalosis would occur if bicarbonate were retained. No respiratory acid-base imbalances are associated with this drug.

The pharmacology instructor is discussing the differences among the various diuretic agents. Which would the instructor cite as a difference between spironolactone and hydrochlorothiazide?

Potassium losses are greater with hydrochlorothiazide than with spironolactone. Unlike hydrochlorothiazide, sprionolactone is a potassium-sparing diuretic. To avoid the risk of hyperkalemia, patients receiving potassium-sparing diuretics should not be given supplemental potassium. Both diuretics act in the distal tubule of the nephron.

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.

Why would potassium-sparing diuretics be contraindicated for clients experiencing renal failure?

They may cause hyperkalemia. Potassium-sparing diuretics are contraindicated in the presence of renal insufficiency because their use may cause hyperkalemia because of the kidneys' ineffective filtration abilities. The remaining options would not result from impaired renal failure.

A hospital client demonstrating peripheral edema has been prescribed furosemide. How should the nurse best determine the extent of the client's desired fluid loss?

Weigh the client daily. The nurse should measure and record weights to assist in determining the amount of mobilization of excess fluid. This is a more accurate gauge of changes in fluid status than skin turgor, urine osmolarity, or chest auscultation.

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 nurse notes that a newly admitted client is currently prescribed both a loop diuretic as well as a thiazide diuretic. The nurse understands what primary rationale for the concurrent use of these two drugs?

increased diuretic effect When an inadequate diuretic response occurs with one drug, people sometimes take two potassium-losing diuretics concurrently. The combination of a loop and a thiazide diuretic has synergistic effects because the drugs act in different segments of the renal tubule. Thus, the rationale for this particular combination is not rooted in prevention of potassium imbalances, increased adherence, or maintenance of a normal heart rate.

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.

The nurse is teaching a 62-year-old client about hydrochlorothiazide, which the health care provider has prescribed for treatment of hypertension. What statement, made by the client, suggests that the client understands the teaching?

"I will need to stand slowly." Diuretics, including hydrochlorothiazide, can cause orthostatic hypotension. Rising slowly to a standing position can reduce the risk of falls. Patients taking diuretics should restrict sodium intake to avoid the need for higher doses, which increase the likelihood of adverse effects. Taking diuretics with food can help avoid the GI irritation frequently associated with these drugs.

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.

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

"You will lose less potassium with spironolactone than with furosemide." Spironolactone promotes retention of sodium and water and excretion of potassium by stimulating the sodium-potassium exchange mechanism in the distal tubule. The client will not have greater potassium losses, water losses, or sodium losses with spironolactone rather than furosemide.

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.

A male client is critically ill with a diagnosis of congestive heart failure exacerbated by a myocardial infarction. The nurse understands that what fast-acting diuretics would be appropriate for the health care provider to order? (Select all that apply.)

Bumetanide Furosemide Fast-acting, potent diuretics such as furosemide and bumetanide are the most likely diuretics to be used in critically ill clients (e.g., those with pulmonary edema).

The nurse is monitoring the results of laboratory testing for a client receiving chlorthalidone. What finding would be a cause for concern?

Hypercalcemia Chlorthalidone is a thiazide-like diuretic that may lead to hypercalcemia (due to decreased calcium excretion), hyperuricemia (increased levels of uric acid due to decreased uric acid secretion), and hypokalemia. Anemia is not associated with this drug.

A 91-year-old client, who is being prepared for discharge, has been prescribed the diuretic spironolactone. While teaching the client about the drug, what major adverse effect should the nurse be sure to mention?

Hyperkalemia The major adverse effect of potassium-sparing diuretics such as spironolactone is hyperkalemia. Clients receiving these drugs should not be given potassium supplements and should not be encouraged to eat foods high in potassium.

Upon her visit to the primary care provider's office, a female client presents with 14 pounds of additional weight since her visit 3 weeks ago. Her lower extremities are quite swollen, and her facial features are puffy. The provider prescribes a diuretic and requests a follow-up visit in 3 days. Two days later, the client contacts the office and is so dyspneic that she is hard to understand over the phone. An ambulance is dispatched, and she is admitted to the hospital for rapid diuresing. Which diuretic will most likely be the initial drug of choice?

Loop diuretic Loop diuretics are the diuretics of choice when rapid effects are required.

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.

A client is receiving hydrochlorothiazide. The nurse would expect to administer this drug by which route?

Oral Hydrochlorothiazide is only available as an oral preparation. Only chlorothiazide can be given by intravenous infusion.

An older adult client has a complex medical history that includes heart failure, type 1 diabetes, and diabetic nephropathy. The nurse has questioned a 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 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 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.

A male client has been ordered spironolactone (Aldactone) for hypertension. Which statement by the client indicates a need for further education?

"I will take the medication when my blood pressure is elevated." Spironolactone (Aldactone) should be taken daily to decrease blood pressure, not only when blood pressure is elevated. Spironolactone (Aldactone) is a potassium-sparing diuretic; therefore, no additional potassium is needed. Adverse reactions include gynecomastia, headache, diarrhea, and cramping. It is important that the client weigh himself daily.

A nurse understands that loop diuretics are considered high ceiling diuretics because they:

cause a greater diuresis. High ceiling diuretics are those that cause a greater degree of diuresis than other diuretics.

A patient is switched from furosemide (Lasix) to spironolactone (Aldactone). The patient asks the nurse why she has been switched to a new medicine. What is the best answer that will provide patient education regarding the change?

"You will lose less potassium with spironolactone than with furosemide." Spironolactone promotes retention of sodium and water and excretion of potassium by stimulating the sodium-potassium exchange mechanism in the distal tubule. The patient will not have greater potassium losses, water losses, or sodium losses with spironolactone rather than furosemide.

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.

A client who is allergic to sulfonamide would use what diuretic cautiously?

Hydrochlorothiazide There is a known cross-sensitivity of some sulfonamide-allergic clients to sulfonamide nonantibiotics, such as thiazides.

A nurse is preparing to administer a diuretic that antagonizes the action of aldosterone. Which drug would the nurse be most likely to administer?

Spironolactone Spironolactone is a potassium-sparing diuretic that exerts its diuretic effect by antagonizing the action of aldosterone. Furosemide is a loop diuretic when given with lithium increases the risk for lithium toxicity. Hydrochlorothiazide given with anesthetics increases the anesthetic effectiveness. Acetazolamide when given with primidone for seizures, decreases the primidone effectiveness.

A nurse obtains an allergy history from a client based on the understanding that which class is associated with a cross-sensitivity reaction with sulfonamides?

Thiazide diuretics A cross-sensitivity reaction may occur with the thiazide diuretics and sulfonamides. For clients who take carbonic anhydrase inhibitors during treatment for glaucoma, contact the primary health care provider immediately if eye pain is not relieved or if it increases. When a client with epilepsy is being treated for seizures, a family member of the client should keep a record of all seizures witnessed and bring this to the primary health care provider at the time of the next visit. Contact the primary health care provider immediately if the number of seizures increases. Potassium-sparing diuretics can lead to hyperkalemia and is most likely to occur in clients with an inadequate fluid intake and urine output, those with diabetes or renal failure, older adults, and those who are severely ill, and teach the client to avoid the use of salt substitutes containing potassium. Osmotic diuretics such as mannitol or urea for treatment of increased intracranial pressure caused by cerebral edema, perform neurologic assessments (response of the pupils to light, level of consciousness, or response to a painful stimulus) in addition to vital signs at the time intervals ordered by the primary health care provider.

Which diuretic will most likely be the initial drug of choice when a client demonstrates dyspnea related to pulmonary edema?

furosemide Loop diuretics, like furosemide, are the diuretics of choice when rapid effects are required since they produce extensive diuresis for short periods, after which the kidney tubules regain their ability to reabsorb sodium. Thiazide diuretics, like hydrochlorothiazide, are the drugs of choice for most clients who require diuretic therapy, especially for long-term management of heart failure and hypertension. In clients with heart failure and inadequate renal function, the addition of spironolactone, a potassium-sparing diuretic, allows smaller doses of loop diuretics and potassium supplements to be administered as spironolactone reduces urinary potassium loss. Osmotic diuretics, like mannitol, are useful in managing oliguria or anuria, and it may prevent acute renal failure (ARF) during prolonged surgery, trauma, or infusion of cisplatin, an antineoplastic agent.

The nurse is caring for a 68-year-old female client with type 1 diabetes mellitus whose health care provider has ordered hydrochlorothiazide. As a consequence of taking the diuretic, the client may need to:

increase her insulin dose. One adverse effect of potassium-losing diuretics, such as the thiazides, is hyperglycemia. Clients with diabetes mellitus may require larger doses of hypoglycemic agents (e.g., insulin) while taking these diuretics to control blood sugar levels. Decreasing potassium intake is inappropriate for clients taking thiazides because it increases the risk of hypokalemia. Increasing sodium intake would lessen the effectiveness of the diuretic.

An adult client with multiple chronic health problems has been prescribed furosemide in the management of hypertension. When reviewing this client's current medication administration record, what drug should signal the nurse to a potentially increased risk of hypokalemia?

prednisone Corticosteroids increase the risk of hypokalemia in clients who are taking furosemide. Vitamin D, calcium supplements, and nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen do not have this effect.

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.

An adult client with a diagnosis of hypertension has been prescribed oral furosemide. What goal should the nurse identify when planning this client's medication teaching session?

The client will identify strategies for limiting sodium intake. The reason for furosemide use should guide client teaching. In most instances, it is necessary to initiate measures to limit sodium intake. Key considerations should include not adding salt to food during preparation or at the dinner table, reading food labels carefully to be aware of hidden sources of sodium, and avoiding processed or high-sodium foods. Blood glucose monitoring is not indicated, and there is no need for increased fluid intake. Renal anatomy and physiology are not priority teaching points.