Can a 26‑kg child receive a single intramuscular dose of 1300 mg ceftriaxone (50 mg/kg) for treatment?

Can You Give 1300 mg of Ceftriaxone as a Single Dose to a 26-kg Child?

Yes, you can administer 1300 mg (50 mg/kg) of ceftriaxone as a single intramuscular or intravenous dose to a 26-kg child for specific indications, particularly gonococcal bacteremia, arthritis, or disseminated infection, where this dosing is explicitly recommended by CDC guidelines. 1, 2

Weight-Based Dosing Calculation

• For a 26-kg child, the calculation is straightforward: 50 mg/kg × 26 kg = 1300 mg, which falls well below the maximum single dose of 2 grams for non-meningeal infections. 2, 3

• This dose is appropriate for children weighing <45 kg with gonococcal bacteremia or arthritis, where CDC guidelines specifically recommend 50 mg/kg IM or IV once daily for 7 days (maximum 1 g per day). 1, 2

Indication-Specific Guidance

Gonococcal Infections (Bacteremia/Arthritis)

• The CDC explicitly recommends 50 mg/kg IM or IV once daily for children <45 kg with gonococcal bacteremia, arthritis, or disseminated infection, making 1300 mg appropriate for this 26-kg patient. 1, 2

• Treatment duration is 7 days, extended to 10-14 days if meningitis is documented. 1, 2

Other Serious Non-Meningeal Infections

• For serious miscellaneous infections (pneumonia, sepsis, osteomyelitis, pyelonephritis), the FDA-approved dosing is 50-75 mg/kg/day, which can be given once daily or divided every 12 hours, with a maximum of 2 grams daily. 3, 2

• A single 1300-mg dose (50 mg/kg) is within the recommended range and has been extensively studied in pediatric populations. 4, 5, 6

Meningitis (Different Dosing)

• For bacterial meningitis, the dose is 100 mg/kg/day (which would be 2600 mg for this child), not 50 mg/kg, so 1300 mg would be inadequate for CNS infections. 1, 2, 3

Evidence Supporting Once-Daily Dosing at 50 mg/kg

• Multiple pediatric studies demonstrate that 50 mg/kg once daily achieves adequate trough concentrations exceeding the MIC of common pathogens (H. influenzae, S. aureus, E. coli, S. pneumoniae) for non-CNS infections. 4, 5

• A study of 35 children treated with 50 mg/kg once daily showed that all but one patient had trough levels exceeding the MIC of the infecting organism, with a satisfactory clinical response in all evaluable patients. 5

• Another study of 201 children receiving 50-80 mg/kg once daily reported an overall clinical cure rate of 94% and bacteriologic cure rate of 97% for serious infections including pneumonia, cellulitis, osteomyelitis, and pyelonephritis. 6

• Recent pharmacokinetic modeling in critically ill children confirms that 100 mg/kg once daily provides adequate exposure for susceptible pathogens (MIC ≤0.5 mg/L) in most patients, with 50 mg/kg twice daily recommended only for highly resistant organisms or augmented renal clearance. 7

Route of Administration

• Both intramuscular and intravenous routes are acceptable for this dose. 1, 2, 3

• Intramuscular injection should be administered deep into a large muscle mass, and families should be counseled that IM injection can be painful. 2

• For IV administration, the dose should be infused over 30-60 minutes in pediatric patients to reduce adverse effects. 3, 7

Maximum Dose Considerations

• The 1300-mg dose is well below the pediatric maximum of 2 grams daily for non-meningeal infections and 4 grams daily for meningitis. 2, 3

• CDC and AAP guidelines emphasize that pediatric doses should not exceed adult doses even when weight-based calculations suggest higher amounts. 2

Critical Contraindications

• Do not use ceftriaxone in hyperbilirubinemic neonates, especially premature infants, due to risk of bilirubin encephalopathy. 2, 3

• Do not mix with calcium-containing solutions in neonates ≤28 days due to risk of fatal ceftriaxone-calcium precipitation. 3

• For neonates requiring IV administration, infuse over 60 minutes to reduce bilirubin displacement risk. 3

Practical Algorithm for 26-kg Child

1. Confirm indication: Is this for gonococcal bacteremia/arthritis (50 mg/kg once daily for 7 days) or another serious infection (50-75 mg/kg/day once daily or divided)?

2. Calculate dose: 50 mg/kg × 26 kg = 1300 mg (appropriate single dose)

3. Verify not meningitis: If CNS infection suspected, use 100 mg/kg/day (2600 mg), not 1300 mg

4. Choose route: IM (deep into large muscle, counsel about pain) or IV (infuse over 30-60 minutes)

5. Plan duration: 7 days for gonococcal infections; 7-14 days for other serious infections depending on clinical response

6. Add chlamydia coverage: If gonococcal infection, add azithromycin 1 g orally (or 20 mg/kg for children <45 kg) as single dose if Chlamydia trachomatis not excluded. 1, 3

Common Pitfalls to Avoid

• Do not underdose meningitis: 1300 mg is inadequate for CNS infections; use 100 mg/kg/day (2600 mg for this child). 1, 3

• Do not forget chlamydia coverage: Gonococcal infections require concurrent antichlamydial therapy if chlamydia not ruled out. 1, 3

• Do not use in neonates with hyperbilirubinemia: Ceftriaxone displaces bilirubin from albumin, risking kernicterus. 2, 3

• Do not mix with calcium in neonates: Fatal precipitates can form; this is less of a concern in older children but still avoid Y-site calcium administration. 3