Pharmacology Ch 51 (2)

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 Rationale: 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.

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

"It's okay to take it with food." Rationale: 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.

What would be a contraindication to the use of carbonic anhydrase inhibitors?

Allergy to sulfonamides Rationale: Carbonic anhydrase inhibitors are sulfonamides, and as such are contraindicated in patients with an allergy to sulfonamides. Carbonic anhydrase inhibitors are used cautiously in patients with adrenocortical insufficiency, respiratory acidosis, and COPD because these conditions could be exacerbated by the use of the drug.

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 Rationale: The nurse will advise the patient to avoid foods high in potassium, which include apricots, avocados, bananas, cantaloupe, fish, honeydew, kiwi, meat, milk, oranges, potatoes, poultry, prunes, spinach, sweet potatoes, tomatoes, winter squash, and yams. Triamterene achieves its diuretic effect by inhibiting transport of sodium in the distal tubules independent of aldosterone. This mechanism causes increased loss of sodium, water, bicarbonate, and calcium and promotes retention of potassium and magnesium. Hyperkalemia can be a serious adverse effect of the drug.

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 Rationale: 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.

When describing the action of chlorothiazide, what would a nurse include?

Blocking of the chloride pump Rationale: Chlorothiazide, a thiazide diuretic, blocks the chloride pump. Carbonic anhydrase inhibitors such as acetazolamide block the action of carbonic anhydrase. Spironolactone, a potassium-sparing diuretic, acts as an aldosterone antagonist. Amiloride and triamterene, potassium-sparing diuretics, block potassium secretion through the tubule.

A 75-year-old client is diagnosed with atrial fibrillation and chronic congestive heart failure. The health care provider orders a combination of digoxin and diuretics to treat the client's diseases. Recent laboratory results indicate that the client's potassium level is 2 mEq/L. This client is at risk for which problem?

Digoxin toxicity Rationale: When digoxin and diuretics are given concomitantly, the risk of digoxin toxicity is increased due to diuretic-induced hypokalemia.

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

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 Rationale: 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 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 Rationale: 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.

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 Rationale: 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.

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. Rationale: 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.

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 Rationale: 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.

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

cause a greater diuresis Rationale: High-ceiling diuretics are those that cause a greater degree of diuresis than other diuretics. The term high ceiling only refers to the amount of diuresis produced. Loop diuretics may have more adverse effects in comparison to potassium-sparing diuretics but this has no connection to the term high ceiling. Loop diuretics achieve their effect with a relatively small dose. Loop diuretics do cause a loss of potassium but so do thiazide and thiazide-like diuretics.

A client, prescribed digoxin and furosemide, is at risk for developing which adverse effect?

digoxin toxicity Rationale: When digoxin and diuretics are used concomitantly, the risk of digoxin toxicity is increased. The client is at risk for hypokalemia, not hyperkalemia. The client is not at risk for hyperglycemia or tachycardia.

A nurse is caring for a 78-year-old patient with renal insufficiency and chronic heart failure who is receiving rapid infusions of high-dose furosemide. It will be a priority for the nurse to monitor for:

ototoxicity Rationale: Ototoxicity can occur with rapid intravenous administration, especially in patients with poor renal function and in those receiving high doses of furosemide. Although usually transient, ototoxicity may result in permanent damage. Rapid infusions of high-dose furosemide would not place the patient at risk for hepatic encephalopathy. Excessive diuresis from furosemide can result in dehydration and vascular thrombosis, but they would not be the priority in this case.

What substance is reabsorbed in the ascending limb of the loop of Henle?

sodium Rationale: 30% of all filtered sodium is reabsorbed by the ascending loop of Henle.

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

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 Rationale: Because in acute settings with high doses they can produce a loss of fluid of up to 20 lb/d, loop diuretics are the drugs of choice when a rapid and extensive diuresis is needed.

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. Rationale: 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.