What is the recommended dose of ampicillin (Ampicillin)/sulbactam (Sulbactam) for pediatric patients?

Recommended Dose of Ampicillin-Sulbactam for Pediatric Patients

For pediatric patients 1 year of age or older, the recommended dose of ampicillin-sulbactam is 300 mg/kg/day (based on total ampicillin + sulbactam content) administered intravenously in equally divided doses every 6 hours, which corresponds to 200 mg ampicillin/100 mg sulbactam per kg per day. 1

Dosing by Age and Weight

Infants and Children ≥1 Year of Age

• Standard dosing: 300 mg/kg/day IV divided every 6 hours (q6h), representing the total drug content 1

  • This translates to 200 mg ampicillin/100 mg sulbactam per kg per day 1
  • Alternative guideline recommendation: 100-200 mg ampicillin/kg/day divided every 6 hours 2

• Children weighing ≥40 kg: Should be dosed according to adult recommendations (1.5-3 g every 6 hours), with a maximum sulbactam dose not exceeding 4 grams per day 1

Infants <1 Year of Age

• Dosing: 100-150 mg ampicillin/kg/day divided every 6 hours 2
• Note: The FDA label specifically states that safety and efficacy have not been established for intramuscular administration in pediatric patients 1

Administration Guidelines

Route and Infusion Details

• Intravenous administration only for the recommended pediatric dosing 1
• Administer by slow IV injection over at least 10-15 minutes, or as an IV infusion over 15-30 minutes when diluted in 50-100 mL of compatible diluent 1

Duration of Therapy

• Standard course: Should not routinely exceed 14 days of IV therapy 1
• In clinical trials, most children transitioned to oral antimicrobials following initial IV treatment 1
• Average treatment duration in clinical studies was 7 days, with a range of 8-23 days depending on infection severity 3, 4

Special Clinical Contexts

Culture-Negative Endocarditis

• Native valve endocarditis: 300 mg/kg/day IV in 4-6 equally divided doses for 4-6 weeks 2
• This represents a higher frequency of administration (every 4-6 hours) compared to standard dosing 2

Renal Impairment

• Dosing frequency must be reduced in patients with impaired renal function 1
• The ampicillin-to-sulbactam ratio remains constant regardless of renal function 1
• Adjust dosing intervals based on creatinine clearance, following the same principles as ampicillin monotherapy 1

Pharmacokinetic and Safety Considerations

Drug Concentrations and Efficacy

• The 300 mg/kg/day dosing (75 mg/kg q.i.d.) achieves adequate plasma concentrations to cover common pathogens in community-acquired pneumonia 5
• Peak serum concentrations range from 177-200 mcg/mL for ampicillin and 82-102 mcg/mL for sulbactam 6
• Clinical cure rates of 95-100% have been demonstrated across various pediatric infections at these doses 3, 4

Safety Profile

• The combination is well-tolerated in pediatric patients 6
• Side effects are minimal, with rash occurring in <2% of patients and rarely requiring discontinuation 3
• Diarrhea may occur but is generally mild 7

Common Pitfalls to Avoid

• Do not confuse the total drug dose with the ampicillin component alone: The 300 mg/kg/day represents the combined ampicillin + sulbactam content, not just ampicillin 1
• Do not exceed 4 grams/day of sulbactam in any pediatric patient, regardless of weight 1
• Do not use intramuscular administration as the standard route in pediatrics, as safety and efficacy have not been established 1
• Do not extend IV therapy beyond 14 days routinely without reassessing the need for continued parenteral treatment 1