Amoxiclav Dosing for an 11-Year-Old Child Weighing 22 kg
For an 11-year-old child weighing 22 kg, the appropriate dose of Amoxiclav (amoxicillin/clavulanate) is 990 mg of amoxicillin component per day, divided into two doses of 495 mg each (approximately 45 mg/kg/dose twice daily), or for severe infections/high-resistance areas, 1980 mg per day divided into two doses of 990 mg each (45 mg/kg/dose twice daily using the high-dose regimen). 1
Standard Dosing Framework
The dosing of Amoxiclav in pediatric patients is primarily weight-based and depends on infection severity and local resistance patterns 1, 2:
Mild to Moderate Infections
- Standard dose: 25 mg/kg/day of amoxicillin component divided every 12 hours 2
- For this 22 kg child: 275 mg twice daily (550 mg total daily)
- This translates to approximately 2.2 mL of 250/62 suspension twice daily 1
Severe Infections or High-Resistance Areas
- High-dose regimen: 90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses 1
- For this 22 kg child: 990 mg twice daily (1980 mg total daily)
- This provides the critical 14:1 ratio of amoxicillin to clavulanate 1
When to Use High-Dose Therapy
High-dose Amoxiclav (90 mg/kg/day) is strongly indicated when any of these risk factors are present 1:
- Age <2 years (this child is 11 years, so this doesn't apply)
- Daycare attendance
- Recent antibiotic use within past 3 months
- Incomplete Haemophilus influenzae type b vaccination
- Geographic area with >10% penicillin-resistant Streptococcus pneumoniae prevalence
- Moderate to severe illness presentation
- Concurrent purulent acute otitis media
Practical Dosing by Formulation
Using Oral Suspension (Most Common in Pediatrics)
For standard-dose therapy (mild infections):
- Use 250/62 mg per 5 mL suspension
- Dose: 5 mL twice daily 1
- This provides approximately 500 mg amoxicillin daily (22.7 mg/kg/day)
For high-dose therapy (severe infections/resistant organisms):
- Use the 14:1 ratio formulation (if available)
- Dose: Calculate to achieve 45 mg/kg per dose twice daily 1
- For 22 kg: approximately 990 mg per dose
Using Tablets (If Child Can Swallow)
- Standard adult tablets are typically 250/125 mg or 500/125 mg
- For this weight, tablets may result in underdosing unless multiple tablets are used 1
Treatment Duration
- Standard duration: 10 days for most respiratory tract infections 1
- Minimum duration: 7 days after patient becomes symptom-free 1
- Clinical improvement should be evident within 48-72 hours; if not, reassess diagnosis and consider treatment failure 1
Critical Pitfalls to Avoid
Underdosing is a major clinical error that leads to treatment failure and promotes antimicrobial resistance 1:
- Using 40-45 mg/kg/day when 90 mg/kg/day is indicated results in inadequate tissue concentrations to overcome resistant organisms 1
- The difference in adverse effects between standard and high-dose regimens is negligible, while efficacy against resistant pathogens is substantially improved 1
- Always verify the suspension concentration (125/31 vs 250/62) before calculating volume to prevent dosing errors 1
Monitoring and Follow-Up
- Expect clinical improvement within 48-72 hours of starting therapy 1
- If no improvement or worsening occurs after 72 hours, reevaluate for:
- Treatment failure with resistant organisms
- Incorrect diagnosis
- Complications requiring imaging or specialist consultation
- Need for alternative antibiotic therapy 1
Adverse Effects
- Common adverse effects include diarrhea, nausea, vomiting, and rash 1
- The high-dose 14:1 ratio formulation (90/6.4 mg/kg/day) causes less diarrhea than other amoxicillin-clavulanate preparations while maintaining superior efficacy 1
- Serious hypersensitivity reactions are contraindications to use 2