What is the recommended dosage of amoxicillin (amoxicillin) + potassium clavulanate for pediatric patients?

Amoxicillin-Clavulanate Dosing for Pediatric Patients

For most pediatric infections requiring amoxicillin-clavulanate, the recommended dosage is 90 mg/kg/day of the amoxicillin component with 6.4 mg/kg/day of clavulanate, divided into 2 doses daily, with a maximum of 4000 mg amoxicillin per day. 1

Standard High-Dose Regimen

The high-dose formulation provides a 14:1 ratio of amoxicillin to clavulanate and is the preferred regimen for most pediatric infections, particularly respiratory tract infections. 1 This dosing achieves adequate tissue concentrations to overcome penicillin-resistant Streptococcus pneumoniae and β-lactamase-producing organisms. 1

Key dosing parameters:

• 90 mg/kg/day of amoxicillin component divided into 2 doses 1
• 6.4 mg/kg/day of clavulanate 1
• Maximum single dose: 2000 mg of amoxicillin 1
• Maximum daily dose: 4000 mg of amoxicillin 1

Age-Specific Dosing

Neonates and Infants < 3 Months

• 30 mg/kg/day divided every 12 hours based on the amoxicillin component 2
• Use the 125 mg/31.25 mg per 5 mL oral suspension formulation 2

Infants and Children ≥ 3 Months

• Standard dose: 45 mg/kg/day in 3 doses OR 90 mg/kg/day in 2 doses 1
• The twice-daily regimen (90 mg/kg/day) is preferred as it significantly reduces diarrhea compared to three-times-daily dosing 2

Children Weighing ≥ 40 kg

• Dose according to adult recommendations 2
• For severe respiratory infections: 875 mg/125 mg every 12 hours 2

Indication-Specific Dosing

Respiratory Tract Infections (Pneumonia, Sinusitis)

• High-dose regimen: 90 mg/kg/day in 2 divided doses for children at risk of resistant organisms 3, 1
• Risk factors include: age < 2 years, daycare attendance, recent antibiotic use (within 4-6 weeks), moderate-to-severe illness 1
• Duration: 10 days for most respiratory infections 1

β-Lactamase Producing H. influenzae

• 45 mg/kg/day in 3 doses OR 90 mg/kg/day in 2 doses 1
• The twice-daily regimen is preferred for better adherence and fewer gastrointestinal side effects 2

Preseptal Cellulitis

• 80-90 mg/kg/day of amoxicillin with 6.4 mg/kg/day clavulanate in 2 divided doses 4
• Duration: 10-14 days, with some experts recommending continuation until 7 days symptom-free 4
• Evaluate for clinical improvement within 48-72 hours 4

Alternative Lower-Dose Regimen

For mild infections in children without risk factors for resistant organisms:

• 45 mg/kg/day in 2 doses may be considered 5
• However, this is generally not recommended as first-line for most infections requiring amoxicillin-clavulanate 1

Practical Dosing by Suspension Concentration

Using 125 mg/31.25 mg per 5 mL suspension:

• Ages 1-12 months: 2.5 mL three times daily (standard dose) 1
• Ages 1-6 years: 5 mL three times daily (standard dose) 1

Using 250 mg/62.5 mg per 5 mL suspension:

• Ages 7-12 years: 5 mL three times daily (standard dose) 1

Critical caveat: These are standard-dose regimens. For high-dose therapy (90 mg/kg/day), calculate the exact volume based on the child's weight and the suspension concentration being used. 1

Intravenous Dosing

For severe infections requiring IV therapy:

• 30 mg/kg three times daily IV for all pediatric ages 1
• Consider IV therapy for children unable to tolerate oral medication or with severe infections 4

Common Pitfalls to Avoid

Do not underdose: Using standard doses when high-dose therapy is indicated leads to treatment failure with resistant organisms. 1 The difference between 45 mg/kg/day and 90 mg/kg/day is clinically significant for resistant pathogens. 1

Verify suspension concentration: Always confirm whether you're using 125/31 or 250/62 suspension before calculating volume to avoid dosing errors. 1

Do not substitute formulations: Two 250 mg/125 mg tablets are NOT equivalent to one 500 mg/125 mg tablet due to different clavulanate content. 2 Similarly, different chewable tablet formulations are not interchangeable. 2

Phenylketonuria warning: The 200 mg/28.5 mg per 5 mL and 400 mg/57 mg per 5 mL suspensions contain aspartame and should not be used in phenylketonuric patients. 2

Monitoring and Follow-Up

• Expect clinical improvement within 48-72 hours of starting therapy 1, 4
• If no improvement or worsening occurs after 72 hours, reevaluate and consider switching antibiotics or further investigation 3, 1
• Complete the full course even if symptoms improve before completion 1

Adverse Effects

The most common adverse effects are gastrointestinal, including diarrhea, nausea, and vomiting. 1 The high-dose 14:1 ratio formulation (90/6.4 mg/kg/day) causes less diarrhea than other amoxicillin-clavulanate preparations while maintaining efficacy. 1 Recent evidence suggests even lower clavulanate concentrations (80 mg amoxicillin/2.85 mg clavulanate/kg/day) may reduce side effects without compromising efficacy, though this is not yet standard practice. 6

Storage and Preparation

Reconstituted oral suspension must be stored under refrigeration and discarded after 10 days. 2 Shake well before each use. 2