What is the recommended dosage and administration of Furosemide (Lasix) for patients with edema or hypertension?

Furosemide Dosage and Administration for Edema and Hypertension

For patients with edema or hypertension, the recommended initial oral dose of furosemide is 20-80 mg given as a single dose, with subsequent dosing adjusted based on clinical response. 1

Dosing for Edema

Adults

• Initial dose: 20-80 mg orally as a single dose 1
• If needed, the same dose can be administered 6-8 hours later or increased 1
• Dose may be increased by 20-40 mg increments, given no sooner than 6-8 hours after the previous dose 1
• Once optimal response is determined, administer the individualized dose once or twice daily (e.g., 8 AM and 2 PM) 1
• In severe edematous states, doses may be carefully titrated up to 600 mg/day 1
• For efficient and safe mobilization of edema, consider giving furosemide on 2-4 consecutive days each week 1

Pediatric Patients

• Initial dose: 2 mg/kg body weight as a single dose 1
• If response is inadequate, may increase by 1-2 mg/kg no sooner than 6-8 hours after previous dose 1
• Maximum recommended dose: 6 mg/kg body weight 1

Heart Failure with Congestion

• For acute heart failure or decompensated heart failure in diuretic-naïve patients: 20-40 mg IV furosemide 2
• For patients already on chronic diuretic therapy: initial IV dose should be at least equivalent to their oral dose 2
• Loop diuretics are recommended for patients with evidence of congestion or fluid retention 3
• Maintenance diuretics should be considered in patients with history of congestion to prevent recurrent symptoms 3
• Treatment goal: eliminate clinical evidence of fluid retention using the lowest effective dose to maintain euvolemia 3

Dosing for Hypertension

Adults

• Initial dose: 80 mg daily, usually divided into 40 mg twice a day 1
• Adjust dosage according to blood pressure response 1
• If response is inadequate, add other antihypertensive agents 1
• When adding furosemide to existing antihypertensive regimen, reduce dosage of other agents by at least 50% to prevent excessive blood pressure drop 1

Geriatric Patients

• Start at the lower end of the dosing range for both edema and hypertension 1
• Careful monitoring is required due to increased risk of dehydration and electrolyte imbalances 1

Administration Considerations

Intravenous Administration

• For acute heart failure with congestion: 20-40 mg IV bolus initially 3, 2
• In patients with volume overload, dose may be increased based on renal function and history of chronic oral diuretic use 3
• Total furosemide dose should remain <100 mg in first 6 hours and <240 mg during first 24 hours 3
• Consider a bolus of 0.5-2 mg/kg IV furosemide at the end of albumin infusions for patients with edema and hypoalbuminemia 3

Monitoring Requirements

• Regular monitoring of symptoms, urine output, renal function, and electrolytes is essential 2
• Consider bladder catheterization to accurately monitor urinary output in acute settings 3, 2
• When doses exceed 80 mg/day for prolonged periods, careful clinical observation and laboratory monitoring are particularly advisable 1

Special Considerations

Diuretic Resistance

• Diuretic resistance can occur with high doses (≥80 mg furosemide twice daily) 4
• Strategies to overcome resistance include:
  • Escalation of loop diuretic dose 3
  • Intravenous administration (bolus or continuous infusion) 3, 5
  • Combination of different diuretic classes 3

Combination Therapy

• Thiazides in combination with loop diuretics may be useful in cases of diuretic resistance 3
• For volume-overloaded heart failure, thiazides (hydrochlorothiazide 25 mg) and aldosterone antagonists (spironolactone, eplerenone 25-50 mg) can be used with loop diuretics 3

Potential Adverse Effects

• Hypokalaemia, hyponatraemia, hyperuricaemia 3
• Hypovolaemia and dehydration 3
• Neurohormonal activation 3
• May increase hypotension following initiation of ACEI/ARB therapy 3
• Patients with hypotension (SBP <90 mmHg), severe hyponatremia, or acidosis are unlikely to respond well to diuretic treatment 2

Caution

• High doses of diuretics may lead to hypovolemia, hyponatremia, and increase the likelihood of hypotension when initiating ACE inhibitors or ARBs 2
• Diuretics should not be used in isolation but always combined with other guideline-directed medical therapy for heart failure that reduces hospitalizations and prolongs survival 3