Maximum Dose of Furosemide (Lasix)
The maximum recommended oral dose of furosemide (Lasix) is 600 mg per day for adults with clinically severe edematous states, though doses should be carefully titrated based on response and monitored for adverse effects. 1
Dosing Guidelines by Patient Population
Adults with Edema
- Initial dose: 20-80 mg as a single dose
- Titration: May increase by 20-40 mg every 6-8 hours until desired diuretic effect is achieved
- Maximum daily dose: 600 mg/day 1
- Administration strategy: Most effective when given on 2-4 consecutive days each week rather than continuously 1
Adults with Hypertension
- Initial dose: 80 mg/day, usually divided into 40 mg twice daily
- Titration: Adjust according to blood pressure response
Pediatric Patients
- Initial dose: 2 mg/kg body weight as a single dose
- Titration: May increase by 1-2 mg/kg no sooner than 6-8 hours after previous dose
- Maximum recommended dose: 6 mg/kg body weight 1
Geriatric Patients
- Lower initial doses recommended
- More careful monitoring required due to increased risk of dehydration and orthostatic hypotension 2
Special Clinical Scenarios
Cirrhosis with Ascites
- Maximum dose: 160 mg/day 3
- Often used in combination with spironolactone in a 40:100 mg ratio 3
- Discontinue if severe hyponatremia (serum sodium <125 mmol/L), acute kidney injury, worsening hepatic encephalopathy, or incapacitating muscle cramps develop 3
Heart Failure
- Standard maximum: 600 mg/day 1
- In refractory heart failure: High-dose furosemide (≥500 mg/day) has been used successfully with careful monitoring 4
- Highest reported dose in refractory cases: Up to 8 g/day in exceptional circumstances 4
Renal Failure
- Patients on hemodialysis: Doses up to 1000-2000 mg/day have been used to maintain residual diuresis 5
- Acute renal failure: Total daily dose should not exceed 100 mg in children 6
Monitoring Requirements
When using high doses of furosemide (>80 mg/day) for prolonged periods:
- Regular clinical observation
- Laboratory monitoring of electrolytes (especially potassium, sodium)
- Renal function tests
- Assessment for adverse effects 1
Important Precautions
Discontinue furosemide if:
- Serum sodium falls below 125 mmol/L
- Acute kidney injury develops
- Severe hypokalemia occurs (<3 mmol/L)
- Incapacitating muscle cramps develop 3
Potential adverse effects with high doses:
- Ototoxicity (tinnitus, hearing loss)
- Electrolyte imbalances
- Dehydration
- Gout 4
Clinical Pearls
- When doses exceed 80 mg/day, careful monitoring becomes particularly important 1
- In patients with cirrhosis, the combination of furosemide with spironolactone (100 mg:40 mg ratio) is more effective than either agent alone 3
- For patients with diuretic resistance, continuous infusion may be more effective than bolus dosing 2
- Periodic reevaluation of clinical status and diuretic requirements is critical for optimal management 7
While very high doses (>600 mg/day) have been reported in the literature for refractory cases, these should only be considered in specialized settings with close monitoring and when standard maximum doses have failed to achieve the desired clinical response.