What is the recommended dose of Monocef (ceftriaxone) for pediatric patients?

Monocef (Ceftriaxone) Pediatric Dosing

For most pediatric infections, ceftriaxone should be dosed at 50-75 mg/kg/day given once daily, with severe infections requiring 50-100 mg/kg/day and meningitis requiring 100 mg/kg/day divided every 12 hours (maximum 4 g daily). 1

Age-Specific Dosing for Neonates

• Neonates ≤7 days old: 50 mg/kg/day given every 24 hours 1
• Neonates >7 days and ≤2000 g: 50 mg/kg/day given every 24 hours 1
• Neonates >7 days and >2000 g: 50-75 mg/kg/day given every 24 hours 1
• Critical contraindication: Never use ceftriaxone in hyperbilirubinemic neonates due to risk of bilirubin displacement 1

Weight-Based Dosing Algorithm

Children <45 kg

Uncomplicated infections (urethritis, cervicitis, pharyngitis, proctitis):

• Single dose of 125 mg IM 2

Bacteremia or arthritis:

• 50 mg/kg IM or IV once daily for 7 days (maximum 1 g) 2, 1

Meningitis:

• 50 mg/kg IM or IV once daily for 10-14 days (maximum 2 g) 2
• Alternative dosing: 100 mg/kg/day divided every 12-24 hours (maximum 4 g daily) 1

Children ≥45 kg

• Use adult dosing regimens 2

Indication-Specific Dosing

Severe Infections (Pneumonia, Sepsis)

• Standard dose: 50-100 mg/kg/day given once daily or divided every 12-24 hours 1
• For critically ill children: Current evidence supports 100 mg/kg once daily as adequate for most patients 3
• For augmented renal clearance or less-susceptible pathogens: Consider 50 mg/kg twice daily to improve target attainment 3

Bacterial Meningitis

• Recommended dose: 100 mg/kg/day divided every 12-24 hours (maximum 4 g daily) 1
• CSF penetration: Achieves concentrations 480-5,600 times above the MIC of causative bacteria 4
• Duration: 10-14 days depending on pathogen and clinical response 1

Community-Acquired Pneumonia

• 50-100 mg/kg/day given once daily or divided every 12-24 hours 1
• For pneumococcal pneumonia with penicillin resistance: 100 mg/kg/day every 12-24 hours 1

Complicated Intra-Abdominal Infections

• 50-75 mg/kg/day given every 12-24 hours 1

Gonococcal Infections

Conjunctivitis (children ≤45 kg):

• 25-50 mg/kg IV or IM single dose (maximum 250 mg) 1

Uncomplicated infections:

• 125 mg IM single dose 2

Bacteremia, arthritis, or meningitis:

• 50 mg/kg/day (maximum 1 g) for 7 days 2
• Extend to 10-14 days for meningitis 2

Pharmacokinetic Considerations

• Half-life in pediatric patients: 4.2-4.6 hours in children with meningitis 4, but can range from 6.6-16.8 hours in neonates 5
• Peak concentrations: 216 mcg/mL after 50 mg/kg IV dose, 275 mcg/mL after 75 mg/kg IV dose 6
• Protein binding: 95% at low concentrations, decreasing to 85% at higher concentrations 6
• Once-daily dosing is effective for most serious pediatric infections due to the long half-life 7, 8

Critical Dosing Pitfalls to Avoid

1. Never exceed adult maximum doses: Pediatric doses should not exceed 4 g daily even when weight-based calculations suggest higher amounts 1

2. Do not use lower dosing ranges for severe sepsis: Use 80-100 mg/kg/day rather than 50 mg/kg/day for critically ill patients 1

3. Avoid ceftriaxone in hyperbilirubinemic neonates: Risk of kernicterus from bilirubin displacement 1

4. Consider twice-daily dosing for:

   • Patients with estimated GFR >80 mL/min/1.73 m² 3
   • Areas with high prevalence of less-susceptible pathogens (MIC ≥0.5 mg/L) 3
   • Meningitis cases requiring sustained CSF concentrations 1

5. Adjust for specific pathogens:

   • If staphylococcal infection suspected: Add flucloxacillin 50 mg/kg every 6 hours plus gentamicin 7.5 mg/kg daily 1
   • If Listeria concern: Add ampicillin 50 mg/kg every 6 hours 1

Administration Routes

• Both IM and IV routes are acceptable 2, 6
• IM injection is painful; counsel patients accordingly 1
• IV doses should be infused over 30 minutes for optimal pharmacokinetics 6