What is the role of furosemide in treating abdominal swelling?

Role of Furosemide in Treating Abdominal Swelling (Ascites)

Furosemide is a second-line diuretic that should be used in combination with spironolactone for the treatment of ascites in cirrhosis, starting at 40 mg/day and titrating up to a maximum of 160 mg/day as needed. 1

First-Line Treatment Approach for Ascites

Ascites in cirrhosis requires a structured approach to management:

1. Initial Assessment:

   • Determine if ascites is tense (requiring paracentesis) or mild-moderate
   • Evaluate for underlying cirrhosis and its severity

2. Standard Treatment Protocol:

   • Sodium restriction: 88 mmol/day (2000 mg/day) 1
   • Diuretic therapy:
     • Primary agent: Spironolactone 50-100 mg/day (can increase to 400 mg/day) 1
     • Secondary agent: Furosemide 20-40 mg/day (can increase to 160 mg/day) 1, 2
   • Dosing schedule: Single morning dosing to maximize compliance 1
   • Titration: Increase doses every 3-5 days until adequate natriuresis and weight loss 1

3. For Tense Ascites:

   • Initial large-volume paracentesis (LVP) followed by diuretic therapy 1
   • Albumin infusion (6-8 g per liter of fluid removed) for paracentesis >5L 1

Specific Role of Furosemide in Ascites Management

Furosemide works at the ascending limb of the loop of Henle by inhibiting chloride reabsorption 3. In ascites management:

• Always used as adjunct: Spironolactone is more effective than furosemide alone in cirrhotic ascites 4
• Optimal ratio: Maintain 100 mg spironolactone:40 mg furosemide ratio to maintain normal potassium levels 1
• Delivery mechanism: Furosemide requires active secretion via organic acid pump to reach its site of action 3
• Response prediction: Urinary sodium excretion correlates with urinary furosemide concentration, not plasma levels 3

Monitoring and Dose Adjustments

• Electrolyte management:

  • Hypokalemia: Reduce or temporarily withhold furosemide 1
  • Hyperkalemia: Reduce or stop spironolactone 1

• When to stop diuretics:

  • Severe hyponatremia (<120-125 mmol/L)
  • Acute kidney injury (serum creatinine >2.0 mg/dL)
  • Hepatic encephalopathy
  • Severe muscle spasms 1

• Target weight loss:

  • With peripheral edema: No specific limit but carefully monitor
  • Without peripheral edema: 0.5 kg/day 1

Special Considerations

• Refractory ascites: Defined as unresponsive to sodium restriction and maximum diuretic doses (spironolactone 400 mg/day and furosemide 160 mg/day) 1

• Alternative administration: Continuous furosemide infusion may achieve better natriuresis in some patients with poor response to oral therapy 5

• Albumin combination: For select patients with severe hypoalbuminemia and diuretic resistance, combining furosemide with albumin may enhance diuretic efficacy 6

• Pharmacokinetic considerations: Patients with cirrhotic ascites may have altered furosemide kinetics, including doubled elimination half-life and volume of distribution 7

Pitfalls to Avoid

1. Never use furosemide as monotherapy for ascites - significantly less effective than spironolactone in cirrhotic patients 4

2. Avoid NSAIDs in patients with ascites - can reduce sodium excretion, induce azotemia, and convert diuretic-sensitive patients to diuretic-resistant 1, 4

3. Don't rely on serial paracentesis alone for diuretic-sensitive patients - address the underlying sodium retention 1

4. Avoid rapid dose escalation - allow 3-5 days between dose increases to prevent electrolyte abnormalities 1

5. Don't discharge patients without follow-up - patients should be seen within approximately one week of discharge 1