40 Questions
Which area of the kidney returns 60% to 70% of sodium and water from the filtered fluid back to the bloodstream?
Proximal convoluted tubule (proximal tubule)
Which drug class accelerates the rate of urine formation and results in the removal of sodium and water?
Diuretics
Where does the initial filtering of blood take place in the kidney?
Glomerulus
What is the main structural unit of the kidney where diuretics exert their effect?
Nephron
What is the reason for patients taking furosemide (Lasix) to avoid prolonged exposure to the sun?
The drug can cause photosensitivity
What adverse effect can furosemide (Lasix) have on patients?
Orthostatic hypotension
Why should patients not stop taking furosemide (Lasix) without consulting their health care provider?
To avoid potential health risks
How often should patients weigh themselves while taking furosemide (Lasix)?
Once a day
What dietary recommendation should be given to patients taking furosemide (Lasix)?
Eat foods rich in potassium
What is the potential consequence of stopping furosemide (Lasix) without consulting a health care provider?
Experiencing adverse health effects
What should patients do if they experience a weight gain or loss of approximately 3 lb while taking furosemide (Lasix)?
Report it
What is the potential consequence of prolonged exposure to the sun while taking furosemide (Lasix)?
Developing photosensitivity
What is the recommended action for patients experiencing orthostatic hypotension while taking furosemide (Lasix)?
Consult a health care provider
What is the recommended frequency for patients to report a weight gain or loss while taking furosemide (Lasix)?
Approximately 3 lb
What is the reason for encouraging patients taking furosemide (Lasix) to eat foods rich in potassium?
To prevent potassium deficiency
What is the rationale behind patients weighing themselves once a day while taking furosemide (Lasix)?
To monitor for weight gain or loss
Which part of the nephron returns 60% to 70% of sodium and water from filtered fluid?
Proximal tubule
Where do loop diuretics act to inhibit chloride and sodium resorption?
Ascending limb of the loop of Henle
What is the primary mechanism of action of loop diuretics?
Inhibition of chloride and sodium resorption
What is the main clinical use of loop diuretics?
Treating edema
Which of the following is a potential adverse effect of loop diuretics?
Hypokalemia
With which of the following drug types can interactions occur when using loop diuretics?
NSAIDs
How do potassium-sparing diuretics interfere with sodium and water retention?
Competitively bind to aldosterone receptors
What is the main effect of potassium-sparing diuretics on sodium and water excretion?
Promote excretion of sodium and water
Which conditions are spironolactone and triamterene indicated for?
Hyperaldosteronism, hypertension, and heart failure
What is a potential adverse effect of potassium-sparing diuretics?
Hyperkalemia
Which of the following can increase the risk of lithium toxicity when used with loop diuretics?
Loop diuretics
What is the effect of loop diuretics on renal prostaglandins?
Increase renal prostaglandins
Which electrolyte imbalance is most commonly associated with thiazide and thiazide-like diuretics?
Hypokalemia
At what level of creatinine clearance does Metolazone remain effective?
10-20 mL/min
What should be monitored in patients with diabetes taking thiazide or loop diuretics?
Blood sugar levels
What is a potential adverse effect of potassium-sparing diuretics?
Hyperkalemia
What should patients prescribed furosemide (Lasix) be instructed to do regarding sun exposure?
Avoid prolonged sun exposure
What is the most common adverse electrolyte finding resulting from the administration of furosemide (Lasix)?
Hypokalemia
What is the primary mechanism of action of thiazide and thiazide-like diuretics?
Inhibit tubular reabsorption of sodium and chloride ions
What should be monitored in patients prescribed diuretics with digitalis preparation?
Digitalis toxicity
What is the main clinical use of loop diuretics?
Reduction of peripheral edema
What should patients do if they experience orthostatic hypotension while taking furosemide (Lasix)?
Change positions slowly
What is the rationale behind patients weighing themselves once a week while taking furosemide (Lasix)?
To monitor for fluid overload
What is the effect of loop diuretics on renal prostaglandins?
Inhibit their production
Study Notes
Loop and Potassium-Sparing Diuretics: Mechanism of Action and Clinical Considerations
- Proximal tubule returns 60% to 70% of sodium and water from filtered fluid
- 20% to 25% of sodium resorbed in ascending loop of Henle, and 5% to 10% in distal tubule
- Loop diuretics act directly on ascending limb of loop of Henle to inhibit chloride and sodium resorption
- Loop diuretics increase renal prostaglandins, leading to blood vessel dilation and reduced peripheral vascular resistance
- Loop diuretics are useful in treating edema
- Loop diuretics can cause adverse effects such as dizziness, headache, and hypokalemia
- Drug interactions with loop diuretics can occur with NSAIDs and vancomycin
- Use of loop diuretics with lithium can increase the risk of lithium toxicity
- Potassium-sparing diuretics interfere with Na-K exchange and competitively bind to aldosterone receptors
- Potassium-sparing diuretics block sodium and water retention and promote excretion of sodium and water
- Spironolactone and triamterene are indicated for hyperaldosteronism, hypertension, and heart failure
- Adverse effects of potassium-sparing diuretics include CNS effects, urinary frequency, and hyperkalemia
Thiazide and Thiazide-Like Diuretics
- Mechanism of action: Inhibit tubular resorption of Na, Cl, and K ions in distal convoluted tubules, resulting in excretion of H2O, Na, and Cl, and to a lesser extent, K
- Drug effects: Lower peripheral vascular resistance, depletion of Na and H2O (and K), should not be used if creatinine clearance is less than 30-50, Metolazone remains effective to a creatinine clearance of 10 mL/min
- Indications: Hypertension (one of the most prescribed group of drugs for this)
- Adverse effects: Dizziness, headache, blurred vision, anorexia, nausea, vomiting, diarrhea, impotence, jaundice, leukopenia, hypokalemia, hyperglycemia, hyperuricemia, hypochloremic alkalosis
- Preform: History and physical exam, assess baseline fluid volume state, I+O, serum electrolytes, take in the AM to avoid sleep disturbance
- Nursing implications: Monitor serum K levels during therapy, all diuretics monitor K, maintain proper nutritional and fluid volume, diuretics with digitalis preparation should be taught to monitor for digitalis toxicity, patients with diabetes taking thiazide or loop diuretics should monitor blood sugar and watch for elevated levels
- Nursing implications (Cont.): Change positions slowly and rise slowly, log daily weight, follow-up visits and lab work, monitor for hyperkalemia with potassium-sparing diuretics
- Nursing implications (Cont.): Monitor for therapeutic effects: Reduction of edema, fluid volume overload, improvement in manifestations of heart failure, reduction of hypertension, return to normal intraocular pressures
- Case study: Loop diuretics provide rapid diuresis due to their rapid onset of action and are effective for patients with reduced kidney function (creatinine clearance below 25 mL/min)
- Case study: Patients receiving furosemide (Lasix) should be assessed for cross-sensitivity to sulfonamides
- Case study: The most common electrolyte finding resulting from the administration of furosemide (Lasix) is hypokalemia
- Case study: Discharge teaching for patients prescribed furosemide (Lasix) should include instructions to avoid prolonged sun exposure, weigh themselves once a week and report a gain or loss of more than 1 lb
Test your knowledge of loop, thiazide, and potassium-sparing diuretics with this quiz. Learn about their mechanisms of action, clinical considerations, indications, adverse effects, and nursing implications. Master the essential information for using these diuretics in clinical practice.
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