What is the dose of ceftriaxone (Ceftriaxone) per weight?

Ceftriaxone Dosing by Weight in Pediatric Patients

The recommended dose of ceftriaxone for pediatric patients varies by indication, with standard dosing ranging from 50-100 mg/kg/day, administered once daily or divided every 12-24 hours, with a maximum of 4 g daily. 1

Age-Specific Dosing

• For neonates with postnatal age ≤7 days, ceftriaxone should be dosed at 50 mg/kg/day given every 24 hours 1
• For neonates with postnatal age >7 days and ≤2000 g, the dose remains 50 mg/kg/day given every 24 hours 1
• For neonates with postnatal age >7 days and >2000 g, the dose is 50-75 mg/kg/day given every 24 hours 1
• Ceftriaxone is contraindicated in hyperbilirubinemic neonates due to risk of bilirubin displacement 1

Indication-Specific Dosing

Severe Infections

• For bacterial meningitis: 100 mg/kg/day divided every 12-24 hours (maximum 4 g daily) 1, 2, 3
• For severe 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 given every 12-24 hours 1
• For sepsis: 50-75 mg/kg/day given every 12-24 hours 1

Moderate Infections

• For less severe infections: 50-75 mg/kg/day given once daily or divided every 12-24 hours 1
• For complicated intra-abdominal infections: 50-75 mg/kg/day given every 12-24 hours 1

Specific Pathogens

• For gram-negative enteric bacilli: 100 mg/kg/day divided every 12 hours or 80 mg/kg/day every 24 hours (up to 4 g daily) 4, 1
• For streptococcal infections: 100 mg/kg/day divided every 12 hours or 80 mg/kg/day every 24 hours (up to 4 g daily) 4

Pharmacokinetic Considerations

Ceftriaxone has favorable pharmacokinetic properties that allow for once-daily dosing in many cases:

• After a 50 mg/kg IV dose in pediatric patients with meningitis, the maximum plasma concentration reaches 216 mcg/mL with a half-life of 4.6 hours 5
• After a 75 mg/kg IV dose, the maximum plasma concentration increases to 275 mcg/mL 5
• CSF concentrations in patients with inflamed meninges average 5.6-6.4 mcg/mL, which is significantly above the MIC for most susceptible pathogens 5, 6

Special Considerations

• For gonococcal conjunctivitis in children weighing ≤45 kg, use 25-50 mg/kg body weight IV or IM as a single dose, not to exceed 250 mg IM 1
• For bacteremia or arthritis, 50 mg/kg/day given daily for 7 days is recommended 1
• For treatment of infective endocarditis caused by streptococci, ceftriaxone can be given as 100 mg/kg/day divided every 12 hours or 80 mg/kg/day every 24 hours (up to 4 g daily) 4

Administration Routes

• Ceftriaxone can be administered intravenously or intramuscularly 5
• Complete absorption occurs following IM administration with maximum plasma concentrations occurring between 2-3 hours post-dose 5
• Multiple IV or IM doses at 12-24 hour intervals result in 15-36% accumulation above single dose values 5

Clinical Evidence Supporting Once-Daily Dosing

Single daily dosing has been proven effective in multiple studies:

• A study of 57 pediatric patients with bacterial meningitis showed that after an initial loading dose of 100 mg/kg, a maintenance dose of 80 mg/kg as a single daily dose was effective with a 100% bacteriological cure rate 3
• Another study of 43 children with serious infections demonstrated a 98% bacteriological cure rate with single daily doses of 50-100 mg/kg 7
• CSF trough levels remain well above the MIC for most pathogens even 24 hours after dosing 6, 2

The evidence strongly supports that ceftriaxone's extended half-life allows for effective once-daily dosing in most pediatric infections, with appropriate dose adjustments based on the severity of infection and the suspected pathogen.