What is the recommended dosage of torsemide (a loop diuretic) for patients with heart failure or cirrhosis?

Torsemide Dosing for Heart Failure and Cirrhosis

For heart failure, start with 10-20 mg once daily and titrate up to a maximum of 200 mg daily; for cirrhosis with ascites, start with 5-10 mg once daily (always combined with spironolactone) and do not exceed 40 mg daily. 1

Heart Failure Dosing

Initial Dosing

• Start with 10-20 mg orally once daily 2, 1
• The FDA-approved initial dose range is 10-20 mg, with flexibility based on severity of fluid retention 1
• Torsemide's 12-16 hour duration of action allows convenient once-daily dosing, compared to furosemide's 6-8 hour duration 2, 3

Dose Titration

• If diuretic response is inadequate, double the dose progressively until clinical improvement occurs 1
• Target weight loss of 0.5-1.0 kg daily during active diuresis 2, 3
• The usual daily maintenance dose ranges from 10-20 mg, though higher doses are frequently needed 2
• Maximum studied dose is 200 mg daily 2, 1

Monitoring Parameters

• Monitor daily weights, with patients adjusting their own doses based on weight changes and clinical signs of congestion 2
• Check renal function and electrolytes (particularly potassium and sodium) regularly during titration 2, 3
• Assess for signs of volume depletion, hypotension, or inadequate diuresis 3

Cirrhosis with Ascites Dosing

Initial Dosing

• Start with 5-10 mg once daily, always combined with an aldosterone antagonist (spironolactone) 2, 1
• The combination is essential because aldosterone antagonists are the mainstay of diuretic therapy in cirrhosis 2
• Torsemide is used at one-quarter the dose of furosemide due to its longer half-life and duration of action 2

Dose Titration

• If response is inadequate, double the dose progressively 1
• Maximum dose is 40 mg daily - doses above this have not been adequately studied in cirrhotic patients 1
• For combination therapy, maintain a ratio of spironolactone 100 mg to furosemide 40 mg (or torsemide 10 mg equivalent) 2

Critical Monitoring in Cirrhosis

• Stop or reduce diuretics if serum sodium falls below 125 mmol/L despite fluid restriction 2
• Discontinue if hepatic encephalopathy develops, acute kidney injury occurs (creatinine rise >0.3 mg/dL in 48 hours), or severe muscle cramps appear 2
• Monitor weight loss carefully: no limit with peripheral edema present, but restrict to 0.5 kg/day maximum without edema 2

Chronic Renal Failure Dosing

• Start with 20 mg once daily 1
• Torsemide maintains efficacy independent of renal function, making it advantageous in chronic kidney disease 3
• Titrate upward by doubling if response is inadequate, up to maximum of 200 mg daily 1

Key Advantages of Torsemide Over Furosemide

• Bioavailability is >80% with minimal first-pass metabolism, compared to furosemide's variable 10-90% bioavailability 4, 5
• Oral and intravenous doses are therapeutically equivalent due to high bioavailability 5
• Longer duration of action (12-16 hours vs 6-8 hours) allows once-daily dosing 2, 3
• Can be taken without regard to meals 5

Managing Diuretic Resistance

When maximum doses fail to achieve adequate diuresis:

• Add sequential nephron blockade with a thiazide diuretic (metolazone 2.5-10 mg or hydrochlorothiazide 25-100 mg) rather than exceeding maximum torsemide doses 2, 3
• Verify dietary sodium restriction is being followed (goal <5-6 g salt daily) 2, 3
• Discontinue NSAIDs, which block diuretic effects and worsen renal function 2, 3
• Consider switching from furosemide to torsemide in patients with apparent resistance, as torsemide may be more effective 2, 3

Common Pitfalls to Avoid

• Never use loop diuretics as monotherapy in heart failure - always combine with ACE inhibitors, beta-blockers, and aldosterone antagonists 2, 3
• Never use loop diuretics alone in cirrhosis - aldosterone antagonists must be the foundation of therapy 2
• Avoid excessive diuresis leading to hypovolemia, which increases risk of renal dysfunction and hypotension when initiating ACE inhibitors 2
• Do not use thiazides if eGFR <30 mL/min except when combined synergistically with loop diuretics 2

Adverse Effects Requiring Dose Adjustment

• Hypokalemia: reduce or stop loop diuretic 2
• Hyperkalemia: reduce or stop aldosterone antagonist 2
• Hyponatremia <125 mmol/L: reduce or discontinue diuretics, consider fluid restriction 2
• Rising creatinine or signs of prerenal azotemia: reduce dose or temporarily discontinue 2

Dosing Equivalence

The conversion ratio is furosemide 40 mg = bumetanide 1 mg = torsemide 10 mg 3, 6