Is there a clinical benefit to using furosemide (loop diuretic) and torasemide (loop diuretic) together in patients with fluid overload?

From the Guidelines

There is generally no clinical benefit to using furosemide and torsemide together in patients with fluid overload, and this combination is not recommended in routine clinical practice. When managing fluid overload, it's preferable to optimize the dose of a single loop diuretic rather than combining two medications from the same class. Both furosemide and torsemide work through the same mechanism - inhibiting the sodium-potassium-chloride cotransporter in the ascending loop of Henle - so using them together provides little additional benefit beyond what could be achieved by increasing the dose of either agent alone 1.

Key Considerations

• If a patient shows resistance to one loop diuretic, the better approach would be to either increase the dose of the current medication, switch to the alternative loop diuretic, or add a thiazide diuretic (like hydrochlorothiazide or metolazone) to achieve sequential nephron blockade 1.
• This sequential blockade approach targets different segments of the nephron and can overcome diuretic resistance more effectively than combining two loop diuretics.
• Additionally, using two loop diuretics simultaneously may increase the risk of adverse effects such as electrolyte imbalances, particularly hypokalemia, as well as dehydration, hypotension, and kidney injury.

Clinical Evidence

• A study published in the Journal of Hepatology in 2018 found that the response rate, the rapidity of ascites mobilisation, and the incidence of diuretic-induced complications were similar in patients treated with either torasemide alone or a combination of anti-mineralocorticoids with furosemide 1.
• The 2016 ESC guidelines for the diagnosis and treatment of acute and chronic heart failure recommend using diuretics as a cornerstone in the treatment of patients with AHF and signs of fluid overload and congestion, but do not support the use of two loop diuretics together 1.

Recommendations

• Optimize the dose of a single loop diuretic rather than combining two medications from the same class.
• Consider adding a thiazide diuretic to achieve sequential nephron blockade if a patient shows resistance to a loop diuretic.
• Monitor patients closely for adverse effects when using diuretics, particularly electrolyte imbalances and kidney injury.

From the Research

Clinical Benefit of Using Furosemide and Torasemide Together

• The use of furosemide and torasemide together in patients with fluid overload has been explored in various studies, with some indicating potential benefits of torasemide over furosemide in certain patient populations 2, 3.
• A study published in 2009 found that torsemide demonstrated decreased mortality compared with furosemide in patients with heart failure, as well as decreased hospitalizations and improved New York Heart Association functional classifications 2.
• Another study published in 2020 found that torasemide had a significant effect on increasing urine volume and improving ejection fraction compared with furosemide in heart failure patients 3.
• However, other studies have found no significant difference between torasemide and furosemide in terms of mortality, edema improvement, weight loss, heart rate, and reducing systolic/diastolic blood pressure 4, 3.

Mechanisms of Diuretic Resistance

• Diuretic resistance, which implies a failure to increase fluid and sodium output sufficiently to relieve volume overload, is a major cause of recurrent hospitalizations in patients with chronic heart failure 5.
• The use of multiple diuretics, including loop diuretics like furosemide and torasemide, may be a strategy to overcome diuretic resistance 5.
• However, the concurrent use of diuretics that block different nephron segments may be necessary to achieve optimal diuresis in severely diuretic-resistant patients with heart failure 5.

Comparative Effects of Furosemide and Torasemide

• A systematic review and meta-analysis of randomized controlled trials found that torasemide caused a significant reduction in brain natriuretic peptide level and edema, but no significant difference in glomerular filtration rate, water extraction, and sodium excretion compared with furosemide 4.
• Another study found that oral torasemide had a significant lower hospital stay and superior effect in improving ejection fraction compared with furosemide in heart failure patients 3.
• However, more studies are needed to clarify the effects of torasemide and furosemide in different patient populations and to determine the optimal treatment strategy for patients with heart failure 6.