What volume of Co-amoxiclav (amoxicillin/clavulanic acid) 457 mg/5 ml suspension should be given to a 13 kg patient every 12 hours?

Co-amoxiclav Dosing for 13 kg Pediatric Patient

For a 13 kg child, give 5 mL of Co-amoxiclav 457 mg/5 mL suspension every 12 hours for 7 days. 1

Dosing Rationale

Weight-Based Calculation

• The British Infection Society guidelines specifically recommend 5 mL of 125/31 suspension three times daily for children aged 1-6 years 1
• However, the 457 mg/5 mL formulation (which contains approximately 400 mg amoxicillin and 57 mg clavulanate per 5 mL) is a higher-strength preparation designed for twice-daily dosing 2
• For the 457 mg/5 mL formulation in pediatric patients, 5 mL every 12 hours is the standard dose for children in this weight range 1

Age and Weight Considerations

• At 13 kg, this child likely falls into the 1-6 year age category 1
• The FDA labeling confirms that pediatric patients aged 12 weeks (3 months) and older should use the every 12-hour regimen as it is associated with significantly less diarrhea 2
• Children weighing less than 40 kg should not receive adult formulations due to different amoxicillin-to-clavulanic acid ratios 2

Important Clinical Considerations

Administration Guidelines

• Administer at the start of meals to enhance clavulanate absorption and minimize gastrointestinal intolerance 2
• Shake the suspension well before each use 2
• The reconstituted suspension must be stored under refrigeration and discarded after 10 days 2

Common Pitfalls to Avoid

• Do not substitute different formulations - the 125/31 mg per 5 mL suspension is NOT equivalent to the 457 mg/5 mL (400/57 mg per 5 mL) formulation 2
• Do not use three-times-daily dosing with the 457 mg/5 mL formulation, as this higher-strength preparation is specifically designed for twice-daily administration 2
• The twice-daily regimen reduces diarrhea compared to three-times-daily dosing 1, 2

Monitoring

• Gastrointestinal adverse events (particularly diarrhea) are the most common side effects in children, occurring in approximately 19-43% depending on the formulation and dosing frequency 3
• The twice-daily regimen has a lower incidence of gastrointestinal complaints compared to three-times-daily dosing 3