Can furosemide (Lasix) 20 mg orally daily improve leg edema in a patient with mild congestive heart failure (CHF) and impaired renal function on long-term dialysis?

From the Guidelines

Yes, Lasix (furosemide) 20 mg orally daily can potentially help improve leg edema in a patient with mild congestive heart failure (CHF) who is on long-term dialysis, though its effectiveness may be limited. For dialysis patients, loop diuretics like Lasix can still work between dialysis sessions by promoting additional fluid removal through urination if the patient has residual kidney function 1. The medication works by inhibiting sodium and chloride reabsorption in the kidneys' loop of Henle, increasing urine output and reducing fluid retention. However, the response depends significantly on the patient's remaining kidney function - those with minimal or no residual function may see little benefit. Some key points to consider when using diuretics in patients with heart failure include:

• Diuretics provide relief from the symptoms and signs of pulmonary and systemic venous congestion in patients with HF 1
• The dose requirement must be tailored to the individual patient’s needs and requires careful clinical monitoring 1
• It is essential to monitor potassium, sodium, and creatinine levels during diuretic therapy 1 For dialysis patients with leg edema, a comprehensive approach is often needed, including:
• Sodium restriction
• Elevation of legs when sitting
• Compression stockings
• Ensuring adequate fluid removal during dialysis sessions The nephrologist should be consulted before starting Lasix, as they may need to adjust the dialysis prescription accordingly, and potassium levels should be monitored since electrolyte imbalances can occur even in dialysis patients taking diuretics 1. The most recent and highest quality study 1 supports the use of loop diuretics like furosemide in the treatment of HF, but also highlights the importance of individualizing treatment and monitoring for potential side effects. Overall, while Lasix may be beneficial in improving leg edema in patients with mild CHF on dialysis, its use should be carefully considered and monitored in the context of the patient's overall treatment plan.

From the FDA Drug Label

Edema Furosemide tablets are indicated in adults and pediatric patients for the treatment of edema associated with congestive heart failure, cirrhosis of the liver, and renal disease, including the nephrotic syndrome. The usual initial dose of Furosemide tablets is 20 to 80 mg given as a single dose. The dose may be raised by 20 or 40 mg and given not sooner than 6 to 8 hours after the previous dose until the desired diuretic effect has been obtained.

The dose of 20 mg orally daily of furosemide (Lasix) may improve leg edema in a patient with mild congestive heart failure (CHF). However, the patient's impaired renal function on long-term dialysis should be considered, and the dose may need to be adjusted based on the patient's response.

• The patient's renal function should be closely monitored.
• The dose may be increased if necessary, but careful clinical observation and laboratory monitoring are advisable, especially when doses exceeding 80 mg/day are given for prolonged periods 2.
• Furosemide is indicated for the treatment of edema associated with congestive heart failure, and the initial dose of 20 to 80 mg can be used in adults 2.

From the Research

Furosemide Dosage and Administration

• The effectiveness of furosemide in improving leg edema in patients with mild congestive heart failure (CHF) and impaired renal function on long-term dialysis is not directly addressed in the provided studies.
• However, a study from 1995 3 suggests that a conventional dose of furosemide in combination with distally active diuretics can induce a prompt weight loss exceeding 30 kg with stable renal function in a patient with CHF.

Diuretic Resistance and Its Implications

• Diuretic resistance is a major cause of recurrent hospitalizations in patients with chronic heart failure and predicts death 4.
• Pathophysiological mechanisms of diuretic resistance include an inappropriately high daily salt intake, hyponatremia or hypokalemic, hypochloremic metabolic alkalosis, and reflex activation of the renal nerves 4.

Comparison of Diuretics

• A study from 2021 5 suggests that torasemide has advantages over furosemide in terms of pharmacological properties, reduction of hospitalizations, functional progress, and improvement in the quality of life of patients with heart failure.
• The safety profile of torasemide is more favorable, as it is associated with a reduced risk of hypokalemia compared to furosemide 5.

Subcutaneous Furosemide

• A systematic review from 2025 6 summarizes the current evidence for subcutaneous furosemide in patients with heart failure, suggesting that novel pH-neutral preparations of subcutaneous furosemide achieved similar diuresis, natriuresis, and bioavailability to intravenous furosemide.
• Subcutaneous conventional furosemide was associated with substantial skin irritation and skin infections requiring treatment with antibiotics 6.

Diuretic Treatment in Acute Decompensation of Advanced CHF

• A randomized controlled trial from 2020 7 compared bolus intermittent vs. continuous infusion of furosemide in patients with acute decompensation of advanced chronic heart failure, suggesting that continuous infusion of intravenous furosemide was associated with better decongestion.