Ceftriaxone Dosage per Kilogram
For most pediatric infections, ceftriaxone is dosed at 50-75 mg/kg/day, while bacterial meningitis requires 100 mg/kg/day (maximum 4 grams daily), administered either once daily or divided every 12 hours.
Standard Pediatric Dosing by Indication
General Infections (Non-Meningitis)
- Skin/soft tissue infections: 50-75 mg/kg once daily or divided every 12 hours 1
- Pneumonia: 50-100 mg/kg/day every 12-24 hours 1, 2
- Sepsis (older children): 50 mg/kg daily 3
- Intra-abdominal infections: 50-75 mg/kg/day every 12-24 hours 4
- Maximum daily dose: 2 grams for non-meningitis infections 5
Severe Infections Requiring Higher Doses
- Meningitis: 100 mg/kg/day (maximum 4 grams daily) 6, 7
- Typhoid fever: 80 mg/kg daily 3
- Dysentery (second-line): 50-80 mg/kg daily 3
Single-Dose Indications
- Acute otitis media: 50 mg/kg IM single dose (maximum 1 gram) 5
- Uncomplicated gonorrhea: 250 mg IM single dose (adults) 5
Neonatal Dosing (≤28 Days)
Critical caveat: Ceftriaxone is contraindicated in premature neonates and in any neonate requiring calcium-containing IV solutions due to precipitation risk 5.
For neonates who can receive ceftriaxone:
- Age ≤7 days: 50 mg/kg/day every 24 hours 9, 6
- Age >7 days and ≤2000g: 50 mg/kg/day every 24 hours 9, 6
- Age >7 days and >2000g: 50-75 mg/kg/day every 24 hours 9, 6
- Infant sepsis/meningitis: 50 mg/kg daily (can increase to 100 mg/kg for meningitis after initial dose) 3, 6
Administer IV doses over 60 minutes in neonates to reduce bilirubin encephalopathy risk 5.
Dosing Frequency: Once vs. Twice Daily
The evidence supports both regimens are effective, but with nuances:
- Once-daily dosing (100 mg/kg) achieves higher peak CSF concentrations and reaches therapeutic targets faster in meningitis 8, 10
- Twice-daily dosing (50 mg/kg every 12 hours) maintains more consistent CSF levels throughout the dosing interval 8
- For empirical meningitis treatment, 100 mg/kg once daily is preferred based on pharmacokinetic modeling showing 88% probability of target attainment at 24 hours versus 53% for divided dosing 8
Administration Guidelines
Intravenous
- Standard infusion time: 30 minutes for children and adults 5
- Neonates: Infuse over 60 minutes 5
- Concentration: 10-40 mg/mL (lower concentrations acceptable) 5
Intramuscular
- Concentration: 250 mg/mL or 350 mg/mL 5
- Inject into large muscle mass with aspiration to avoid vascular injection 5
Important Clinical Caveats
Calcium Interactions
- Never mix with calcium-containing solutions (Ringer's, Hartmann's, parenteral nutrition) 5
- In non-neonates, can give sequentially if lines flushed thoroughly between infusions 5
- No interaction with oral calcium products 5
Renal/Hepatic Impairment
- No dose adjustment needed for renal or hepatic dysfunction up to 2 grams daily in adults 5
- Pediatric patients with severe renal impairment may require monitoring but typically no adjustment 6
Maximum Doses
Duration of Therapy
- Meningitis: 7-14 days (or up to 21 days for neonatal meningitis) 3, 6
- Most infections: Continue at least 2 days after symptom resolution, typically 4-14 days 5
- Streptococcus pyogenes: Minimum 10 days 5
Pathogen-Specific Considerations
The dosing recommendations above cover common pathogens (S. pneumoniae, H. influenzae, N. meningitidis) with MICs ≤1-4 mg/L. For S. aureus meningitis (MIC 4 mg/L), neither standard regimen achieves adequate CSF concentrations—vancomycin or alternative therapy is required 8.