Furosemide is used in the management of edema associated with heart failure, nephrotic syndrome, and hepatic cirrhosis. IV furosemide also may be used as an adjunct in the treatment of acute pulmonary edema.
Careful etiologic diagnosis should precede the use of any diuretic. Because the potent diuretic effect of furosemide may result in severe electrolyte imbalance and excessive fluid loss, hospitalization of the patient during initiation of therapy is advisable, especially for patients with hepatic cirrhosis and ascites or chronic renal failure. In prolonged diuretic therapy, intermittent use of the drug for only a few days each week may be advisable. Furosemide may be administered cautiously for additive effect with most other diuretics; however, since furosemide and other loop diuretics (e.g., ethacrynic acid) act in a similar manner, there is no rationale for using these drugs together.
Furosemide is used in the management of edema associated with heart failure. Most experts state that all patients with symptomatic heart failure who have evidence for, or a history of, fluid retention generally should receive diuretic therapy in conjunction with moderate sodium restriction, an agent to inhibit the renin-angiotensin-aldosterone (RAA) system (e.g., angiotensin-converting enzyme [ACE] inhibitor, angiotensin II receptor antagonist, angiotensin receptor-neprilysin inhibitor [ARNI]), a β-adrenergic blocking agent (β-blocker), and in selected patients, an aldosterone antagonist. Some experts state that because of limited and inconsistent data, it is difficult to make precise recommendations regarding daily sodium intake and whether it should vary with respect to the type of heart failure (e.g., reduced versus preserved ejection fraction), disease severity (e.g., New York Heart Association [NYHA] class), heart failure-related comorbidities (e.g., renal dysfunction), or other patient characteristics (e.g., age, race). The American College of Cardiology Foundation (ACCF) and American Heart Association (AHA) state that limiting sodium intake to 1.5 g daily in patients with ACCF/AHA stage A or B heart failure may be reasonable. While data currently are lacking to support recommendation of a specific level of sodium intake in patients with ACCF/AHA stage C or D heart failure, ACCF and AHA state that limiting sodium intake to some degree (e.g., less than 3 g daily) in such patients may be considered for symptom improvement.
Diuretics play a key role in the management of heart failure because they produce symptomatic benefits more rapidly than any other drugs, relieving pulmonary and peripheral edema within hours or days compared with weeks or months for cardiac glycosides, ACE inhibitors, or β-blockers. However, since there are no long-term studies of diuretic therapy in patients with heart failure, the effects of diuretics on morbidity and mortality in such patients are not known. Although there are patients with heart failure who do not exhibit fluid retention in the absence of diuretic therapy and even may develop severe volume depletion with low doses of diuretics, such patients are rare and the unique pathophysiologic mechanisms regulating their fluid and electrolyte balance have not been elucidated.
Most experts state that loop diuretics (e.g., bumetanide, ethacrynic acid, furosemide, torsemide) are the diuretics of choice for most patients with heart failure. If resistance to diuretics occurs, IV administration of a diuretic or concomitant use of 2 or more diuretics (e.g., a loop diuretic and metolazone, a loop diuretic and a thiazide diuretic) may be necessary; alternatively, short-term administration of a drug that increases blood flow (e.g., a positive inotropic agent such as dopamine) may be necessary. ACCF and AHA state that IV loop diuretics should be administered promptly to all hospitalized heart failure patients with substantial fluid overload to reduce morbidity. In addition, ACCF and AHA state that low-dose dopamine infusions may be considered in combination with loop diuretics to augment diuresis and preserve renal function and renal blood flow in patients with acute decompensated heart failure, although data are conflicting and additional study and experience are needed. For additional information,
Furosemide may be administered IV as an adjunct in the treatment of acute pulmonary edema; however, the drug should be used cautiously when pulmonary edema is a complication of cardiogenic shock associated with acute myocardial infarction because diuretic-induced hypovolemia may reduce cardiac output.
Hepatic and Renal Disease
Furosemide also may be used cautiously in the management of edema associated with the nephrotic syndrome and in patients with hepatic cirrhosis, but such edema is frequently refractory to treatment. When metabolic alkalosis may be anticipated, a potassium-rich diet, potassium supplements, or potassium-sparing diuretics may be necessary before and during furosemide therapy to mitigate or prevent hypokalemia in cirrhotic, nephrotic, or digitalized patients.
(See Cautions: Fluid, Electrolyte, Cardiovascular, and Renal Effects.)
Large oral or IV doses of furosemide have been employed as an adjunct to other therapy, including peritoneal dialysis or hemodialysis, in patients with acute or chronic renal failure. In some patients, the use of furosemide may delay the need for dialysis, increase the intervals between dialyses, shorten the period of hospitalization, or permit a slightly more liberal fluid intake.
Furosemide may be used orally for the management of hypertension, especially when complicated by heart failure or renal disease. Furosemide has been used as monotherapy or in combination with other classes of antihypertensive agents. In most patients, hypertension not controllable by thiazides alone probably will not respond adequately to furosemide alone. Because of established clinical benefits (e.g., reductions in overall mortality and in adverse cardiovascular, cerebrovascular, and renal outcomes), ACE inhibitors, angiotensin II receptor antagonists, calcium-channel blockers, and thiazide diuretics generally are considered the preferred drugs for the initial management of hypertension in adults. However, loop diuretics (e.g., furosemide) may be required in place of thiazide diuretics in patients with renal impairment. In addition, loop diuretics may be particularly useful in patients with heart failure and reduced left ventricular ejection fraction (LVEF) who have evidence of fluid retention; although thiazide diuretics provide more persistent antihypertensive effects, a loop diuretic is the preferred diuretic in most patients with heart failure. For information on antihypertensive therapy for patients with chronic kidney disease or heart failure,
For further information on the role of diuretics in antihypertensive therapy and information on overall principles and expert recommendations for treatment of hypertension,
IV furosemide has been found useful as an adjunct to hypotensive agents in the treatment of hypertensive crises, especially when associated with acute pulmonary edema or renal failure. In addition to producing a rapid diuresis, furosemide enhances the effects of other hypotensive drugs and counteracts the sodium retention caused by some of these agents.
Furosemide has been used IV alone or with 0.9% sodium chloride injection or sodium sulfate to increase renal excretion of calcium in patients with hypercalcemia. Oral furosemide has been suggested for maintenance.