What are the dosing guidelines for diuretics, such as furosemide (Lasix) and bumetanide, in pediatric patients?

Pediatric Diuretic Dosing Guidelines

For pediatric patients requiring diuretic therapy, furosemide should be dosed at 0.5-2 mg/kg per dose intravenously or orally up to six times daily, with a maximum of 10 mg/kg per day based on the degree of edema and diuresis achieved. 1

Furosemide Dosing by Route and Age

Intravenous Administration

• Neonates and Infants:

  • Initial dose: 1 mg/kg given slowly under close medical supervision 2
  • If response inadequate: May increase by 1 mg/kg no sooner than 2 hours after previous dose 2
  • Maximum dose: 6 mg/kg/day (general pediatrics); 1 mg/kg/day for premature infants 2
  • Administration rate: Infuse over 5-30 minutes to avoid hearing loss 1

• Children:

  • Initial dose: 1 mg/kg body weight 2
  • Titration: May increase by 1 mg/kg if needed, no sooner than 2 hours after previous dose 2
  • Maximum dose: 6 mg/kg/day 2

Oral Administration

• Initial dose: 2 mg/kg body weight as a single dose 3
• Titration: If response inadequate, may increase by 1-2 mg/kg no sooner than 6-8 hours after previous dose 3
• Maximum dose: 6 mg/kg/day 3
• Maintenance therapy: For stable patients, 2-5 mg/kg/day in combination with a thiazide or potassium-sparing diuretic 1

Special Considerations for Specific Conditions

Congenital Nephrotic Syndrome

• Consider IV bolus of furosemide (0.5-2 mg/kg) at the end of each albumin infusion 1
• For severe edema: Start with 0.5-2 mg/kg/dose up to six times daily (maximum 10 mg/kg/day) 1
• High doses (>6 mg/kg/day) should not be given for periods longer than 1 week 1

Critically Ill Infants Post-Cardiac Surgery

• Continuous infusion: 0.1 mg/kg/hour shows better hemodynamic stability with fewer fluctuations in urine output 4
• Intermittent dosing: 1 mg/kg every 4 hours produces slightly higher absolute urine output but with greater hemodynamic fluctuations 4

Infants with Normal Renal Function

• Lower initial doses may be appropriate (0.5 mg/kg) as studies show significant diuresis even at this dose 5
• The lowest mean furosemide urinary excretion rate associated with significant diuresis was found to be 0.58 ± 0.33 μg/kg/min 6

Monitoring Requirements

• Fluid status: Regular assessment of hydration, edema, and weight
• Electrolytes: Monitor for hypokalemia, hyponatremia, and hypochloremic alkalosis
• Renal function: Assess diuresis and estimated glomerular filtration rate 1
• Blood pressure: Avoid furosemide in patients with hypotension or hypovolemia 7
• Hearing: High doses or rapid administration increase risk of ototoxicity 1

Important Precautions

• Diuretics should be used with caution and only in cases of intravascular fluid overload (evidenced by good peripheral perfusion and high blood pressure) 1
• Furosemide must be stopped in the case of anuria 1
• In premature infants, doses should not exceed 1 mg/kg/day due to increased risk of side effects 2
• Long-term use in infants with low birth weight increases risk of nephrocalcinosis 8
• Infants may show dehydration 3 hours after furosemide administration, requiring careful monitoring and possible fluid replacement 5

Combination Therapy

• For stable patients, furosemide can be given with a thiazide or potassium-sparing diuretic 1
• When using potassium-sparing diuretics, ENaC blockers like amiloride are preferable to spironolactone in nephrotic syndrome 1
• Spironolactone can be used at 1 mg/kg/dose up to 3.3 mg/kg/day (maximum 100 mg/day) 1

Alternative Loop Diuretics

• Bumetanide:
  • More potent than furosemide (40:1 potency ratio)
  • Dosing range: 0.005-0.1 mg/kg every 24 hours 8
  • Half-life in neonates: 1.74-7.0 hours (longer than in adults) 8

By following these dosing guidelines and monitoring protocols, diuretic therapy can be safely and effectively administered to pediatric patients while minimizing the risk of adverse effects.