Lasix Disease Interactions

The use of loop diuretics is contraindicated in patients with anuria.

Loop diuretic therapy should be initiated in the hospital under strict observation in patients with liver cirrhosis and ascites. Sudden alteration of fluid and electrolyte balance may precipitate hepatic encephalopathy and coma in such patients, who are also at increased risk for the development of hypokalemia. Supplemental potassium and/or concomitant use of an aldosterone antagonist or potassium-sparing agent may help prevent hypokalemia and metabolic alkalosis. Loop diuretics should be withheld in patients with hepatic coma until the condition improves.

The use of loop diuretics, particularly at high dosages or during chronic therapy, is commonly associated with loss of electrolytes, including potassium, sodium, chloride, magnesium, and calcium. Potassium and magnesium depletion may lead to cardiac arrhythmias and cardiac arrest. Other electrolyte-related complications include metabolic alkalosis and hyponatremia, which are rarely life-threatening. Excessive diuresis, as indicated by rapid weight loss, may induce dehydration and hypovolemia, which can result in acute hypotension, orthostasis, circulatory collapse, vascular thrombosis and embolism, and abrupt reduction in glomerular filtration and renal blood flow. Severe dehydration is most likely to occur in the elderly and patients under prolonged sodium restriction. Therapy with loop diuretics should be administered cautiously in patients with or predisposed to fluid and electrolyte depletion, including patients with primary or secondary aldosteronism (may have low potassium levels); those with severe or prolonged diarrhea or vomiting; and those with poor nutritional status. Fluid and electrolyte abnormalities should be corrected before initiating therapy, and blood pressure as well as serum electrolyte concentrations monitored periodically and maintained at normal ranges during therapy. Patients should be advised to immediately report signs and symptoms of fluid or electrolyte imbalance, including dry mouth, thirst, weakness, lethargy, drowsiness, restlessness, muscle pains or cramps, muscular fatigue, hypotension, oliguria, tachycardia, arrhythmia, or gastrointestinal disturbances such as nausea and vomiting. Digitalized patients and patients with a history of ventricular arrhythmias should be monitored carefully, since the development of hypokalemia may be particularly dangerous in these patients. The risk of hypokalemia may be minimized by slow diuresis, a lower diuretic dosage, potassium supplementation, or combined use with a potassium-sparing diuretic. Similarly, to prevent excessive dehydration and hyponatremia, sodium intake should be liberalized if clinically feasible.

Tinnitus and hearing loss, both reversible and permanent, have been reported with the use of loop diuretics. Ototoxic effects have generally been associated with rapid intravenous or intramuscular injection, severe renal impairment, unusually high dosages (i.e. several times the usual recommended dosages), and/or concomitant use of other ototoxic agents. Therapy with loop diuretics should be administered cautiously in patients with preexisting vestibular and/or auditory impairment, since it may delay the recognition or confound the diagnosis of a drug-induced ototoxic effect. High-dose parenteral therapy should be administered as controlled infusion.

Impaired effectiveness and possible delayed excretion of loop diuretics may occur in patients with severe renal dysfunction. These individuals may require high dosages that are associated with an increased risk of electrolyte abnormalities (hyponatremia, hypochloremic alkalosis, hypokalemia, hypomagnesemia, hypocalcemia) and ototoxicity (tinnitus, hearing loss). Therapy with loop diuretics should be administered cautiously in patients with significantly impaired renal function. Prolongation of the dosing intervals may be appropriate to prevent drug accumulation. The patient should be monitored closely for the signs and symptoms of fluid or electrolyte imbalance, including dry mouth, thirst, weakness, lethargy, drowsiness, restlessness, muscle pains or cramps, muscular fatigue, hypotension, oliguria, tachycardia, arrhythmia, or gastrointestinal disturbances such as nausea and vomiting. Excessive diuresis should be avoided as it may induce dehydration and hypovolemia, which can result in an abrupt reduction in glomerular filtration and renal blood flow. If increasing azotemia and oliguria occur during treatment of severe progressive renal disease, or if renal function becomes progressively worse as indicated by rising BUN or serum creatinine levels, an interruption or discontinuation of therapy should be considered.

The use of furosemide has been associated with exacerbation or activation of systemic lupus erythematosus. Therapy with furosemide should be administered cautiously in patients with a history of lupus.

Loop diuretics may cause hyperglycemia, glycosuria, and alterations in glucose tolerance tests. Rarely, precipitation of diabetes mellitus has been reported. Therapy with loop diuretics should be administered cautiously in patients with diabetes mellitus, glucose intolerance, or a predisposition to hyperglycemia. Patients with diabetes mellitus should be monitored more closely during therapy, and their antidiabetic regimen adjusted accordingly.

Loop diuretics may decrease the rate of uric acid excretion. Hyperuricemia can occur but is usually asymptomatic and rarely leads to clinical gout except in patients with a history of gout or chronic renal failure. Therapy with loop diuretics should be administered cautiously in such patients.

The use of loop diuretics can cause urinary retention in patients with bladder emptying disorders, prostate hyperplasia, narrowing of the urethra. Caution and monitoring is recommended when using loop diuretics in these patients, especially when commencing therapy.