Question

A nurse is administering a diuretic that inhibits reabsorption of sodium and chloride ions in the distal and proína tubules and in the loop Henle. Which of the following might the nurse be administering? A Mannitol (Osmitrol) B. Spironolactone (Aldactone) Chlorothiazide (Diuni) D. Furosemide (Las)

Answer 1

D . Furosemide (Lasix)

  Loop or high-ceiling diuretics, including furosemide, bumetanide, and torsemide, reversibly inhibit the sodium-potassium-two chloride cotransporter at the luminal thick ascending limb of the loop of Henle, therefore inhibiting the reabsorption of sodium, potassium, and chloride ions.

Therapeutics

Loop diuretics are indicated for acute pulmonary edema and the treatment of hypertension, without or with other antihypertensive drugs. They are also indicated for chronic renal failure and for edema caused by congestive heart failure, renal disease and hepatic disease. Additional uses include treatment of hypercalcemia (given with isotonic saline); severe hyponatremia (given with hypertonic saline); and to treat drug overdose by inducing a diuresis. The diuretic effect of loop diuretics in increased by thiazide diuretics. This can be helpful in some cases, in which greater diuresis is required. In fact, low-dose combinations of diuretics may offer an advantage over use of a single drug in certain cases Ellison (2001). This can be due to preventing compensatory changes to one drug. Compensatory changes lead to a reduced effect of a single drug over time.

Contraindications

Anuria

Allergy to sulfonylureas or sulfonamides, depending on the drug

Excessive sodium and volume depletion

Postmenopausal women with osteoporosis

Adverse Effects

Dizziness, headache, nausea and vomiting, asthenia, hyperglycemia, excessive urination, hyperuricemia, hypokalemia, thirst, hypovolemia, sexual impotence, arthralgia, dyspepsia, cough. By virtue of the fact that loop diuretics may cause hypokalemia, hypocalcemia or hypomagnesemia, the drugs may be associated with changes on the electrocardiogram and arrhythmias including torsades de pointes.

These adverse effects are generally dose-related.

Ototoxicity has been reported especially with high doses of loop diuretics, due to inhibition of the Na+/K+/2Cl−symporter in the inner ear with resulting effects on the endolymph. Ethacrynic acid is the most ototoxic and other loop diuretics are preferred over this drug unless all other loop diuretics are contraindicated. Loop diuretics should be used with caution with other drugs that are established as ototoxic.

Furosemide is a highly effective and quick-acting diuretic whose action, like all of the examined loop diuretics, is associated with blocking reabsorption of ions in the ascending bend of Henle’s loop. It is used for edema syndrome of various origins, edema of the lungs and brain, chronic renal insufficiency, some forms of hypertonic crises, and poisoning by barbiturates and other compounds excreted mainly with urine.

In a number of cases, furosemide has proven more effective than other diuretics. Besides a diuretic effect, it also dilates peripheral vessels. It is frequently used in combination with other antihypertensive drugs. Synonyms of this drug are lazix, lazizix, franil, urosemide, and many others.