How many times stronger is Torsemide than Furosemide (Lasix)

From the Guidelines

Torsemide is approximately 2-4 times stronger than Furosemide (Lasix) in terms of its diuretic effect.

Key Points

• The maximum daily dose of Torsemide is 200 mg, while that of Furosemide is 600 mg 1.
• The duration of action of Torsemide is 12-16 hours, compared to 6-8 hours for Furosemide 1.
• The initial daily dose of Torsemide is 10-20 mg, while that of Furosemide is 20-40 mg 1.
• The potency of Torsemide compared to Furosemide can be estimated based on their equivalent doses, with Torsemide being approximately 2-4 times more potent 1.

Comparison of Loop Diuretics

• The following loop diuretics have different potencies and durations of action:
  • Bumetanide: 10 mg maximum daily dose, 4-6 hours duration of action 1
  • Furosemide: 600 mg maximum daily dose, 6-8 hours duration of action 1
  • Torsemide: 200 mg maximum daily dose, 12-16 hours duration of action 1

Clinical Implications

• The choice of loop diuretic and its dose should be individualized based on the patient's clinical response and renal function 1.
• Close monitoring of renal function and electrolyte levels is essential when using loop diuretics, especially in patients with heart failure or renal impairment 1.

The FDA Drug Labels for torsemide (PO), furosemide (PO) do not address this question.

From the Research

Comparison of Torsemide and Furosemide

• Torsemide and furosemide are both loop diuretics used to treat heart failure and edema, but their potency and efficacy can differ.
• According to a study published in 2009 2, torsemide demonstrated decreased mortality compared with furosemide in patients with heart failure.
• However, a more recent study from 2025 3 found that a dose equivalence of approximately 4:1 (torsemide:furosemide) resulted in similar natriuresis, suggesting that torsemide may be about 4 times stronger than furosemide in terms of diuretic effect.
• Another study from 2023 4 compared the effects of torsemide and furosemide on all-cause mortality in patients hospitalized with heart failure and found no significant difference between the two groups.
• A study from 2003 5 found that torsemide improved functional and social limitation in primary care patients with chronic heart failure, but did not reduce hospitalizations.
• In terms of pharmacokinetics, a study from 1995 6 found that torsemide was more rapidly absorbed and had greater bioavailability than furosemide.

Key Findings

• Torsemide may be approximately 4 times stronger than furosemide in terms of diuretic effect 3.
• Torsemide has been shown to have improved efficacy and safety compared to furosemide in some studies 2, 5.
• However, other studies have found no significant difference between torsemide and furosemide in terms of mortality or hospitalizations 3, 4.
• The choice between torsemide and furosemide should be based on individual patient needs and clinical judgment.