Perfusion and Renal Elimination
6.9 Diuretics
Diuretics
Diuretics are used to decrease blood pressure and to decrease symptoms of fluid overload, such as edema. There are many classifications of diuretics. We will discuss loop, thiazide, and potassium-sparing diuretics. Other diuretics, such as osmotic diuretics, are used to decrease fluid from cerebrospinal fluid and the brain.
Diuretics cause diuresis (increased urine flow) by inhibiting sodium and water reabsorption from the kidney tubules. By eliminating excess water, blood volume and blood pressure, as well as preload, are decreased.
Diuretics are often used in combination with other antihypertensive agents to reduce a client’s blood pressure.
Furosemide
Mechanism of Action
Loop diuretics inhibit absorption of sodium and chloride in the Loop of Henle and proximal and distal tubules, thus causing fluid loss, along with sodium, potassium, calcium, and magnesium losses. Loop diuretics are very potent diuretics and are used when a client has an exacerbation of fluid overload.
Indications for Use
Furosemide is used to treat clients with edema, and clients with hypertension. IV furosemide is used to urgently treat pulmonary edema.
Nursing Considerations Across the Lifespan
The onset of diuresis following oral administration is within 1 hour. The peak effect occurs within the first or second hour. The duration of diuretic effect is 6 to 8 hours. When possible, loop diuretics should be administered in the morning, and evening doses should be avoided (unless urgent) so that sleep is not disturbed.
Nurses should continually monitor for dehydration and electrolyte imbalances that can occur with excessive diuresis, such as dryness of mouth, thirst, weakness, lethargy, drowsiness, restlessness, muscle pains or cramps, muscular fatigue, hypotension, oliguria, tachycardia, arrhythmia, or gastrointestinal disturbances such as nausea and vomiting.
Use cautiously in the geriatric population who have decreased renal function. Kidney function should be monitored closely for all clients because this is a potent medication that works within the kidney tubules.
Monitor the client closely for hypokalemia if furosemide is used concomitantly with digoxin. Hypokalemia may increase the risk of digoxin toxicity.
Adverse/Side Effects
Adverse effects include dehydration, hypotension, and electrolyte imbalances such as hypokalemia. Health care providers may add potassium to a client’s scheduled medication list to decrease risk of hypokalemia. If using IV route, the administration must be given slowly to reduce the risk of the client developing ototoxicity.[1]
Client Teaching & Education
Advise clients to change position slowly, as they may experience orthostatic changes. Clients should also report weight gain of more than three pounds in a day to their healthcare provider. Clients should also be encouraged to enjoy potassium-rich foods during loop diuretic drug therapy.[2]
Furosemide Medication Card
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