Sulbactam Dosing in Pediatric Patients
The recommended dose of sulbactam in children is 100 mg/kg/day (as part of ampicillin-sulbactam 300 mg/kg/day in a 2:1 ratio), administered intravenously in equally divided doses every 6 hours, with a maximum total sulbactam dose not exceeding 4 grams per day. 1
Standard Pediatric Dosing Algorithm
For Children ≥1 Year of Age with Normal Renal Function
- Standard dose: Ampicillin-sulbactam 300 mg/kg/day IV divided every 6 hours (which provides 200 mg/kg/day ampicillin + 100 mg/kg/day sulbactam) 1
- This represents the FDA-approved dosing for pediatric patients and is supported by the American Heart Association guidelines 2, 3
- Maximum daily sulbactam: 4 grams per day regardless of weight 1
- Weight-based cap: Children weighing ≥40 kg should receive adult dosing (1.5-3 g every 6 hours) 1
Administration Details
- Route: Intravenous infusion over 15-30 minutes 1
- Frequency: Every 6 hours (q6h) for most infections 1
- Duration: Typically should not exceed 14 days of IV therapy; most children transition to oral antimicrobials after initial IV treatment 1
Infection-Specific Dosing Modifications
For Endocarditis (Native or Prosthetic Valve)
- Dose: 300 mg/kg/day IV divided into 4-6 equally divided doses 2, 3
- Duration: 4-6 weeks for native valve endocarditis 2
- Combination therapy: Must be combined with gentamicin 3 mg/kg/day IV/IM in 3 divided doses 2
For Complicated Intra-Abdominal Infections
- Dose: 200 mg/kg/day of ampicillin-sulbactam given every 6 hours 3
- Note this is lower than the standard 300 mg/kg/day, reflecting the specific guideline recommendation for this indication 3
For Community-Acquired Pneumonia (Empiric Therapy)
- Optimal dose: 75 mg/kg q.i.d. (four times daily) may be superior to 45 mg/kg t.i.d. for empiric coverage of Streptococcus pneumoniae (MIC90 = 2 μg/mL) and Haemophilus influenzae (MIC90 = 4 μg/mL) 4
- This higher frequency achieves better pharmacodynamic target attainment (50% fT>MIC) 4
Renal Impairment Adjustments
Dosing must be reduced in pediatric patients with renal dysfunction, following the same principles as adults:
- CrCl ≥30 mL/min/1.73m²: Standard dosing every 6-8 hours 1
- CrCl 15-29 mL/min/1.73m²: Reduce frequency to every 12 hours 1
- CrCl 5-14 mL/min/1.73m²: Reduce frequency to every 24 hours 1
The ratio of ampicillin to sulbactam remains constant (2:1) regardless of renal function 1
Pharmacokinetic Considerations
Age-Related Factors
- Age does not significantly affect pharmacokinetics in children aged 1-12 years 5, 4
- Mean half-life: approximately 0.77-0.89 hours for ampicillin and 0.81-0.88 hours for sulbactam across pediatric age groups 5, 6
- Peak serum concentrations are dose-proportional: 30 mg/kg achieves approximately 82-102 μg/mL for sulbactam and 177-200 μg/mL for ampicillin 5, 7
Urinary Excretion
- Both ampicillin and sulbactam are primarily renally excreted 5
- Urinary recovery rates: 50-75% for both components within 6 hours 7, 6
- Sulbactam shows slightly higher urinary recovery (72-73%) compared to ampicillin (52-57%) 6
Critical Pitfalls to Avoid
Underdosing in Severe Infections
- Do not use doses below 300 mg/kg/day for serious infections requiring hospitalization 1
- For multidrug-resistant organisms (particularly Acinetobacter species), even higher sulbactam doses may be needed, though pediatric data for high-dose regimens (>100 mg/kg/day sulbactam) are limited 3, 8
Intramuscular Administration
- Safety and efficacy of IM administration in pediatric patients have NOT been established 1
- Always use IV route in children 1
Exceeding Maximum Daily Dose
- Never exceed 4 grams of sulbactam per day, even in adolescents or children >40 kg 1
- This safety limit applies regardless of infection severity 1
Inappropriate Duration
- Avoid IV therapy exceeding 14 days without compelling indication 1
- Transition to oral therapy when clinically appropriate, as was done in clinical trials 1