What is the appropriate Augmentin (amoxicillin‑clavulanate) dose for an 11‑year‑old child weighing about 35 kg with ruptured appendicitis?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: February 19, 2026View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

Augmentin Dosing for Pediatric Ruptured Appendicitis

Direct Answer

Augmentin (amoxicillin-clavulanate) is not recommended as first-line therapy for ruptured appendicitis in an 11-year-old child weighing 35 kg; preferred regimens include piperacillin-tazobactam, carbapenems, or ceftriaxone plus metronidazole. 1


Why Augmentin Is Not Preferred for This Indication

  • The Surgical Infection Society and Infectious Diseases Society of America explicitly recommend against using ampicillin-sulbactam (the IV equivalent of oral Augmentin) as a preferred regimen for complicated appendicitis in children. 1

  • Augmentin lacks adequate coverage for resistant organisms commonly encountered in complicated intra-abdominal infections, which is why broader-spectrum agents are preferred. 1

  • Preferred regimens for complicated appendicitis include piperacillin-tazobactam, carbapenems, advanced cephalosporins with metronidazole, and aminoglycoside-based regimens. 1


If Augmentin Must Be Used (Despite Not Being Preferred)

Dosing Calculation

  • For a 35 kg child with a more severe infection, the FDA-approved dosing is 45 mg/kg/day of the amoxicillin component divided every 12 hours. 2

  • This translates to 1,575 mg total daily dose (35 kg × 45 mg/kg), administered as 787.5 mg (approximately 790 mg) every 12 hours. 1, 2

  • Alternatively, 40 mg/kg/day divided every 8 hours can be used, which equals 1,400 mg daily or approximately 467 mg every 8 hours. 2

Practical Administration

  • Since this child weighs less than 40 kg, use pediatric suspension formulations rather than adult tablets. 2

  • Using the 400 mg/5 mL suspension, each dose would be approximately 10 mL every 12 hours (for the 45 mg/kg/day regimen). 2

  • Administer at the start of meals to enhance clavulanate absorption and minimize gastrointestinal intolerance. 2


Critical Considerations for Complicated Intra-Abdominal Infections

  • β-lactam antibiotic dosages should be maximized if undrained intra-abdominal abscesses may be present. 1

  • The American Academy of Pediatrics and the Infectious Diseases Society of America recommend using guideline-recommended regimens (piperacillin-tazobactam, carbapenem, or ceftriaxone/metronidazole) as first choice for complicated/perforated appendicitis. 1


Treatment Duration & Monitoring

  • For complicated intra-abdominal infections, duration of therapy varies based on the specific condition and clinical response. 3

  • Children on appropriate antibiotic therapy should show clinical improvement within 48–72 hours; if no improvement is seen, reevaluation is necessary. 3

  • Complete the full course of antibiotics as prescribed, even if symptoms improve before completion. 3


Common Pitfalls to Avoid

  • Do not use the 250 mg/125 mg adult tablets in children under 40 kg due to different amoxicillin-to-clavulanate ratios. 2

  • Do not substitute two 250 mg/125 mg tablets for one 500 mg/125 mg tablet, as they contain the same amount of clavulanic acid (125 mg) but different amounts of amoxicillin. 2

  • Verify the suspension concentration before dispensing to avoid dosing errors. 4

  • Most importantly, recognize that Augmentin is suboptimal for this indication and strongly advocate for guideline-concordant therapy with broader-spectrum agents. 1

References

Guideline

Augmentin Dosing for Pediatric Appendicitis

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2026

Guideline

Amoxicillin Dosing Guidelines for Pediatric Patients

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2026

Guideline

Amoxicillin-Clavulanate Dosing in Pediatric Patients

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2026

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.