What is the maximum dose of amoxicillin (amoxicillin)/clavulanate for morbidly obese children with strep throat?

Maximum Dose of Amoxicillin/Clavulanate for Morbidly Obese Children with Strep Throat

For morbidly obese children with strep throat, the maximum dose of amoxicillin/clavulanate should be calculated using 40 mg amoxicillin/kg/day based on ideal body weight (IBW), not to exceed 2,000 mg of amoxicillin component per day, divided into three doses for a 10-day course. 1

First-Line Treatment Options for Strep Throat

• Amoxicillin alone is the preferred first-line treatment for Group A Streptococcal pharyngitis in children at a dose of 50 mg/kg once daily (maximum 1,000 mg) or 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 1
• Penicillin V is an acceptable alternative first-line option at 50-75 mg/kg/day in 3 or 4 doses for 10 days 1
• Amoxicillin/clavulanate (Augmentin) should be reserved for treatment failures or chronic carriers of Group A Streptococcus 1, 2

Dosing Considerations for Morbidly Obese Children

Weight-Based Calculation Method

• For morbidly obese children, ideal body weight (IBW) should be used when calculating doses rather than actual body weight to avoid potential toxicity 3, 4
• Using actual body weight in morbidly obese patients can lead to increased serum concentrations compared to normal-weight patients, potentially causing adverse effects 3

Maximum Dose Parameters

• Standard dosing of amoxicillin/clavulanate is 40 mg amoxicillin/kg/day divided into three doses 1
• The maximum daily dose should not exceed 2,000 mg of amoxicillin component per day 1, 2
• For persistent or recurrent cases, a higher dose formulation (Augmentin ES-600) providing 90 mg/6.4 mg/kg/day of amoxicillin/clavulanate in two divided doses may be considered 5

Alternative Treatment Options for Penicillin-Allergic Patients

• For children with penicillin allergy, the following alternatives can be used 2:
  • Cephalexin: 20 mg/kg twice daily (maximum 500 mg per dose) for 10 days 2
  • Clindamycin: 7 mg/kg three times daily (maximum 300 mg per dose) for 10 days 2
  • Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 2

Treatment Monitoring and Follow-Up

• Assess response to therapy after 72 hours; lack of improvement may indicate treatment failure requiring reevaluation or change in antibiotic 2
• Monitor for adverse effects, which may include diarrhea, nausea, and skin rash 5
• Complete the full 10-day course of treatment even if symptoms resolve earlier to prevent recurrence and complications 2

Important Considerations and Pitfalls

• Avoid using actual body weight for dose calculations in morbidly obese children as this can lead to overdosing and increased risk of adverse effects 3, 4
• Remember that pharmacokinetic properties are altered in obese patients, affecting drug distribution, metabolism, and elimination 3
• Be aware that resistance patterns vary geographically; consider local resistance patterns when selecting antimicrobial therapy 2, 5
• The safety profile of high-dose amoxicillin/clavulanate formulations is similar to conventional formulations, making them appropriate options when indicated 5