What are the recommended dosages for medications in pediatric patients?

Pediatric Medication Dosing Guidelines

Pediatric medication dosing requires weight-based or age-based calculations rather than simply using reduced adult doses, as children have unique physiological differences affecting drug pharmacokinetics and pharmacodynamics. 1

General Principles for Pediatric Dosing

Weight-Based Dosing

• For most medications, dosing should be calculated based on:
  • Weight (mg/kg) for children <2 years or drugs with high volume of distribution
  • Body Surface Area (BSA) for children >2 years or drugs with low volume of distribution 2

Age-Based Considerations

• Neonates (<3 months): Maximum dose of 30 mg/kg/day divided every 12 hours due to immature renal function 3
• Infants and young children: Often require higher mg/kg doses than adults due to higher metabolic rates
• Children >40 kg: May be dosed as adults for many medications 1

Specific Medication Classes and Dosing Examples

Antibiotics

• Amoxicillin:
  • Children <40 kg: 25-45 mg/kg/day divided every 8-12 hours
  • Mild/moderate infections: 25 mg/kg/day divided every 12 hours
  • Severe infections: 45 mg/kg/day divided every 12 hours 3

Antituberculosis Drugs

• Isoniazid:
  • Children: 10-15 mg/kg daily (maximum 300 mg)
  • Twice weekly: 20-30 mg/kg (maximum 900 mg) 1
• Rifampin:
  • Children: 10-20 mg/kg daily (maximum 600 mg) 1
• Pyrazinamide:
  • Children: 15-30 mg/kg daily (maximum 2.0 g) 1

Pulmonary Hypertension Medications

• Epoprostenol:
  • Starting dose: 1-2 ng·kg⁻¹·min⁻¹ IV
  • Maintenance: Usually 50-80 ng·kg⁻¹·min⁻¹ IV 1
• Treprostinil:
  • Starting dose: 2 ng·kg⁻¹·min⁻¹ IV/SC
  • Maintenance: Usually 50-80 ng·kg⁻¹·min⁻¹ IV/SC 1

Emergency Medications

• Atropine:
  • IV/IO: 0.02 mg/kg (minimum 0.1 mg, maximum 0.5 mg for children, 1.0 mg for adolescents)
  • May repeat every 5 minutes to maximum total dose of 1 mg for children, 2 mg for adolescents 1
• Lorazepam (status epilepticus):
  • IV/IM: 0.05-0.10 mg/kg (maximum 4 mg per dose)
  • May repeat every 10-15 minutes if needed 1

MDR-TB Medications

• Linezolid:
  • Children >12 years: 10 mg/kg once daily
  • Children <12 years: 10 mg/kg twice daily 1
• Clofazimine:
  • 2-3 mg/kg daily (maximum 100 mg) 1
• Delamanid:
  • Children ≥13 years and ≥35 kg: 100 mg twice daily
  • Children 6-12 years and 20-34 kg: 50 mg twice daily 1

Special Considerations

Renal Impairment

• For patients with impaired renal function:
  • GFR 10-30 mL/min: 500 mg or 250 mg every 12 hours
  • GFR <10 mL/min: 500 mg or 250 mg every 24 hours
  • Hemodialysis: Additional dose during and after dialysis 3

Cardiac Medications

• Endocarditis treatment (pediatric dosing):
  • Nafcillin/oxacillin: 200 mg/kg/day IV in 4-6 divided doses
  • Gentamicin: 3 mg/kg/day IV/IM in 3 equally divided doses
  • Vancomycin: 40 mg/kg/day IV in 2-3 equally divided doses 1

Common Pitfalls and Safety Considerations

1. Calculation errors: Use standardized weight-based dosing tools or double-check calculations 4

2. Decimal point errors: Always use leading zeros (0.1 mg not .1 mg) and avoid trailing zeros (1 mg not 1.0 mg)

3. Unit confusion: Clearly specify units (mg vs. mcg vs. mL)

4. Age-specific pharmacokinetics: Consider organ maturity, especially in neonates and infants 2

5. Formulation issues: Ensure appropriate concentration and formulation for pediatric administration 5

6. Medication errors: Highest risk with weight-based calculations, especially in emergency settings 4

By following these guidelines and considering the physiological differences between children and adults, clinicians can provide safe and effective medication dosing for pediatric patients.