What is the recommended dose of ceftriaxone (a third-generation cephalosporin antibiotic) for pediatric patients?

Ceftriaxone Pediatric Dosing

For most serious pediatric infections beyond the neonatal period, administer ceftriaxone 50-75 mg/kg/day once daily or divided every 12-24 hours, with a maximum of 2 grams daily for non-meningeal infections; for bacterial meningitis, use 100 mg/kg/day (maximum 4 grams daily) divided every 12-24 hours. 1

Neonatal Dosing (Age-Specific)

Critical contraindication: Never use ceftriaxone in hyperbilirubinemic neonates due to risk of bilirubin encephalopathy. 1

• ≤7 days postnatal age: 50 mg/kg/day given every 24 hours 1
• >7 days and ≤2000 g: 50 mg/kg/day given every 24 hours 1
• >7 days and >2000 g: 50-75 mg/kg/day given every 24 hours 1

Standard Pediatric Dosing by Infection Severity

Less Severe Infections

• Dose: 50-75 mg/kg/day given once daily or divided every 12-24 hours 1
• Indications: Cellulitis, uncomplicated pneumonia, pyelonephritis, sepsis, complicated intra-abdominal infections 1
• Maximum: 2 grams daily 1

Severe Infections

• Dose: 50-100 mg/kg/day given once daily or divided every 12-24 hours 1
• Indications: Severe pneumonia, hospitalized community-acquired pneumonia 1
• Use the higher end (80-100 mg/kg/day) for life-threatening infections, empyema, or documented resistant organisms 1

Bacterial Meningitis

• Dose: 100 mg/kg/day divided every 12-24 hours 1
• Maximum: 4 grams daily 1
• Duration: 10-14 days for pneumococcal meningitis 2
• Recent evidence supports once-daily dosing (100 mg/kg OD) over twice-daily dosing (50 mg/kg BD) for earlier achievement of CSF therapeutic targets 3

Pneumococcal Pneumonia with Penicillin Resistance

• Dose: 100 mg/kg/day given every 12-24 hours for adequate CNS penetration and treatment of resistant strains 1

Specific Infection Dosing

Gonococcal Infections (Weight <45 kg)

• Uncomplicated infections: 125 mg IM single dose 2
• Conjunctivitis: 25-50 mg/kg IV or IM single dose (maximum 250 mg) 1
• Bacteremia or arthritis: 50 mg/kg/day (maximum 1 gram) IM or IV once daily for 7 days 2
• Meningitis: 50 mg/kg/day (maximum 2 grams) IM or IV once daily for 10-14 days 2
• Children ≥45 kg: Use adult dosing regimens 2

Endocarditis (HACEK Organisms)

• Dose: 100 mg/kg/day IV/IM once daily 1
• Duration: 4 weeks for native valve, 6 weeks for prosthetic valve 1
• Maximum: Do not exceed adult dose of 4 grams daily 1

Gram-Negative Enteric Bacilli

• Dose: 100 mg/kg/day divided every 12 hours OR 80 mg/kg/day every 24 hours 1
• Maximum: 4 grams daily 1

Critical Dosing Considerations

Once-Daily vs. Divided Dosing

• Once-daily dosing provides equal efficacy to divided dosing for most infections 4
• For meningitis, recent pharmacokinetic modeling demonstrates 100 mg/kg once daily achieves superior CSF penetration compared to 50 mg/kg twice daily 3
• Once-daily dosing offers greater convenience for outpatient parenteral therapy 5

Common Pitfalls to Avoid

• Do not underdose severe infections: Always use 100 mg/kg/day for life-threatening infections, not the lower 50 mg/kg/day range 1
• Do not exceed maximum adult doses: Even when weight-based calculations suggest higher doses, cap at 2 grams for non-meningeal infections and 4 grams for meningitis 1
• Counsel families about IM injection pain: Intramuscular administration is painful and should be injected deep into large muscle mass 1

Administration Routes

• IV infusion: Typically administered over 30 minutes 6
• IM injection: Acceptable for outpatient therapy; use deep intramuscular injection into large muscle mass 1, 5
• Outpatient therapy: Once-daily IM dosing enables outpatient treatment of serious infections, potentially saving hundreds of hospitalization days 5

Pharmacokinetic Considerations

• Half-life in pediatric patients with meningitis: 4.3-4.6 hours 6
• CSF penetration: Achieves therapeutic concentrations in inflamed meninges (5.6-6.4 mcg/mL after 50-75 mg/kg IV) 6
• Protein binding: 85-95% bound to plasma proteins 6
• Elimination: 33-67% excreted unchanged in urine 6

Safety Profile

• Overall adverse event rate: Approximately 10% in clinical trials 7
• Most common adverse effects: Rash, fever, diarrhea, neutropenia (usually reversible upon discontinuation) 7, 4
• Serious adverse effects are rare and typically do not require discontinuation 7
• Clinical cure rates: 94-97% across multiple studies 7, 5, 8