What to do for a patient with congestive heart failure (CHF) on furosemide (Lasix) 80mg twice daily (bid) intravenously (IV) with a dropping glomerular filtration rate (GFR)?

From the Guidelines

For a patient with congestive heart failure on furosemide (Lasix) 80mg IV twice daily who has a declining GFR, I recommend reducing the furosemide dose and considering a switch to a combination diuretic approach, as this strategy is supported by the most recent and highest quality guidelines, such as those from the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines 1.

Key Considerations

• Decrease the furosemide to 40mg IV twice daily and add metolazone 2.5-5mg orally once daily, given 30 minutes before the morning furosemide dose, as this combination often provides better diuresis while using less furosemide, which is important as declining kidney function can both reduce furosemide effectiveness and increase toxicity risk 1.
• Monitor the patient's fluid status, daily weights, electrolytes (particularly potassium, sodium, and magnesium), and renal function closely - initially daily, then every 2-3 days once stable, to ensure the patient maintains adequate hydration without overhydration, aiming for a gradual weight loss of 1-2 pounds daily until euvolemic.
• If diuresis remains inadequate, consider adding spironolactone 25mg daily if potassium allows, or consulting nephrology for possible ultrafiltration, as the declining GFR indicates worsening cardiorenal syndrome, where heart failure and kidney dysfunction exacerbate each other, requiring careful balancing of diuresis needs against kidney protection 1.

Rationale

• The use of diuretics in heart failure is well-established, with loop diuretics like furosemide being preferred for most patients due to their effectiveness in reducing fluid retention 1.
• However, the development of a declining GFR in a patient on furosemide indicates a need to reassess the diuretic strategy to avoid further renal impairment while still managing fluid overload effectively.
• Combination diuretic therapy, including the addition of metolazone, can enhance diuresis while potentially reducing the required dose of loop diuretics, thus mitigating some of the risks associated with high-dose loop diuretic therapy, such as ototoxicity and nephrotoxicity 1.
• Close monitoring of the patient's condition, including fluid status, electrolytes, and renal function, is crucial to adjust the diuretic regimen as needed and to prevent complications such as dehydration, electrolyte imbalances, and worsening renal function 1.

From the FDA Drug Label

Adults: Parenteral therapy with Furosemide Injection should be used only in patients unable to take oral medication or in emergency situations and should be replaced with oral therapy as soon as practical. Therapy should be individualized according to patient response to gain maximal therapeutic response and to determine the minimal dose needed to maintain that response. Close medical supervision is necessary When furosemide is given for prolonged periods, careful clinical observation and laboratory monitoring are particularly advisable.

The patient with congestive heart failure on furosemide (Lasix) 80mg twice daily intravenously with a dropping glomerular filtration rate (GFR) should be closely monitored.

• Dose adjustment may be necessary to prevent further decline in GFR.
• Alternative treatments or additional therapies should be considered to manage the patient's condition.
• Laboratory monitoring should be continued to assess the patient's response to treatment and adjust the dose as needed 2.
• The use of high-dose parenteral therapy requires careful consideration of the potential risks, including water and electrolyte depletion 2.

From the Research

Patient Management

For a patient with congestive heart failure (CHF) on furosemide (Lasix) 80mg twice daily (bid) intravenously (IV) with a dropping glomerular filtration rate (GFR), several considerations must be taken into account:

• The use of high-dose furosemide has been shown to be effective in treating refractory congestive heart failure, with improvements in symptoms and survival 3.
• However, high-dose furosemide can also lead to a decline in renal function, as seen in the patient's dropping GFR.
• The addition of an A1 adenosine receptor antagonist, such as BG9719, to furosemide therapy may help protect against the decline in renal function while promoting natriuresis 4.
• ACE inhibition has been shown to persistently prevent fluid accumulation and improve functional capacity in patients with congestive heart failure, and may be considered as an adjunct to furosemide therapy 5.
• The method of furosemide administration, whether by bolus injection or continuous infusion, may also impact diuresis and neurohormonal activation, although one study found that bolus administration was equally effective as continuous infusion in patients with severe heart failure 6.

Treatment Options

Treatment options for the patient may include:

• Continuing or adjusting the current furosemide regimen, potentially adding an A1 adenosine receptor antagonist or ACE inhibitor to help protect renal function and improve symptoms.
• Considering alternative diuretic therapies or adjunctive treatments to help manage the patient's congestive heart failure and declining GFR.
• Monitoring the patient's renal function and adjusting the treatment plan as needed to minimize further decline in GFR.

Key Considerations

Key considerations in managing the patient's care include:

• Close monitoring of renal function and adjustment of the treatment plan as needed.
• Consideration of the potential benefits and risks of high-dose furosemide therapy, as well as the potential benefits of adding an A1 adenosine receptor antagonist or ACE inhibitor to the treatment regimen.
• The importance of individualizing treatment to the patient's specific needs and response to therapy, as demonstrated by studies showing that some patients with congestive heart failure can be controlled on relatively low doses of furosemide 7.