What is the recommended pediatric dosing of amoxyclav (amoxicillin‑clavulanic acid) in mg/kg per day, including dosing frequency and treatment duration for common infections?

Amoxicillin-Clavulanate (Amoxyclav) Pediatric Dosing

For most pediatric bacterial infections in children ≥3 months, use high-dose amoxicillin-clavulanate at 90 mg/kg/day of the amoxicillin component with 6.4 mg/kg/day of clavulanate, divided into two doses (maximum 4 g/day amoxicillin), for 10 days. 1, 2

Standard Dosing Algorithm by Indication

Community-Acquired Pneumonia

• Children < 5 years: 90 mg/kg/day amoxicillin component divided twice daily for 10 days 1, 2
• Children ≥ 5 years: 90 mg/kg/day amoxicillin component divided twice daily for 10 days (maximum 4 g/day) 1, 2
• Clinical improvement expected within 48–72 hours; if no improvement occurs, reassess for atypical pathogens or complications 1, 2

Acute Otitis Media

• All children < 2 years: 90 mg/kg/day amoxicillin component + 6.4 mg/kg/day clavulanate divided twice daily for 10 days 2, 3
• Children ≥ 2 years with risk factors: Use the same high-dose regimen 2
• Risk factors include: recent antibiotic use (past 30 days), daycare attendance, severe presentation, or bilateral AOM in children 6–23 months 2

Acute Bacterial Rhinosinusitis

• Children with risk factors: 90 mg/kg/day amoxicillin component + 6.4 mg/kg/day clavulanate divided twice daily for 10–14 days 1, 2, 3
• Children ≥ 2 years without risk factors: 45 mg/kg/day amoxicillin component divided twice daily for 10–14 days 1
• Risk factors include: age < 2 years, daycare attendance, recent antibiotic use, incomplete Hib vaccination, or regional penicillin-resistant S. pneumoniae prevalence > 10% 1, 2

Group A Streptococcal Infections (Treatment Failure)

• After amoxicillin failure: 40 mg/kg/day amoxicillin component divided three times daily (maximum 2,000 mg/day) for 10 days 1

Age and Weight Restrictions

• Minimum age: ≥ 3 months 2
• Children < 3 months: Intravenous regimens (ampicillin + gentamicin or cefotaxime) are preferred; specialist consultation required if oral therapy is considered 2
• Children ≥ 40 kg: Dose as adults using standard adult formulations 1, 3

Practical Dosing by Age (Using Standard Suspensions)

Age-Based Oral Dosing (UK/European Formulations)

• < 1 year (1–12 months): 2.5 mL of 125/31 suspension three times daily 2
• 1–6 years: 5 mL of 125/31 suspension three times daily 2
• 7–12 years: 5 mL of 250/62 suspension three times daily 2
• 12–18 years: 1 tablet (250/125) three times daily 2

Critical caveat: These age-based regimens provide lower total daily doses than the high-dose regimen (90/6.4 mg/kg/day) recommended for resistant organisms. For pneumonia, otitis media with risk factors, or sinusitis with risk factors, calculate the dose based on weight to achieve 90 mg/kg/day divided twice daily. 1, 2

High-Dose Formulation (14:1 Ratio)

• The 14:1 ratio formulation (90 mg amoxicillin/6.4 mg clavulanate per kg/day) causes significantly less diarrhea than other amoxicillin-clavulanate preparations while maintaining efficacy 2, 3
• This formulation achieves middle-ear fluid concentrations sufficient to overcome penicillin-resistant S. pneumoniae with MICs up to 2–4 mg/L 1, 2

When to Use Standard-Dose vs. High-Dose

Standard-Dose (45 mg/kg/day) Indications

• Children ≥ 2 years with uncomplicated respiratory infections and no recent antibiotic exposure 1
• No daycare attendance and not in high-resistance areas 1

High-Dose (90 mg/kg/day) Indications – Use When ANY of the Following Are Present:

• Age < 2 years 1, 2
• Daycare attendance 1, 2, 3
• Recent antibiotic use (within past 30 days) 1, 2
• Incomplete Hib vaccination (< 3 doses) 2
• Regional penicillin-resistant S. pneumoniae prevalence > 10% 1, 2
• Moderate-to-severe illness 1, 2
• Concurrent purulent otitis media 1, 2
• Treatment failure after 48–72 hours on standard-dose amoxicillin 1, 2

Treatment Duration by Indication

• Pneumonia: 10 days 1, 2
• Acute otitis media: 10 days for children < 6 years; 8–10 days for children < 2 years 2
• Acute bacterial rhinosinusitis: 10–14 days for children; 5–7 days may be sufficient for adults 2, 3
• Group A streptococcal infections (after amoxicillin failure): 10 days 1

Clinical Monitoring and Reassessment

• Expected response time: Clinical improvement (reduced fever, pain, irritability) should occur within 48–72 hours 1, 2
• If no improvement at 48–72 hours: Reassess diagnosis, consider atypical pathogens (add macrolide), evaluate for complications, or switch to alternative antibiotic 1, 2
• Fever resolution: Typically within 24–48 hours for pneumococcal pneumonia, though cough may persist longer 1
• Complete the full course even if symptoms improve before completion 1

Maximum Dosing Limits

• Maximum single dose: 2 g amoxicillin per administration 2, 3
• Maximum daily dose: 4 g amoxicillin per day (regardless of weight) 1, 2

Alternatives for Penicillin-Allergic Patients

Non-Anaphylactic Penicillin Allergy

• Second- or third-generation cephalosporins (cefdinir, cefuroxime, cephalexin) are safe; cross-reactivity risk is negligible 1, 3

IgE-Mediated (Type I) Penicillin Allergy

• Clindamycin: 10–20 mg/kg/day divided three times daily 1, 3
• Azithromycin: 12 mg/kg once daily for 5 days (use cautiously due to potential resistance) 1, 3
• Acknowledge inferior efficacy compared with β-lactams 1

Common Pitfalls to Avoid

• Verify suspension concentration (125/31 vs. 250/62) before calculating volume to avoid dosing errors 2
• Do not use subtherapeutic doses; they fail to achieve adequate tissue concentrations, promote resistance, and lead to treatment failure 2
• Most upper respiratory tract infections are viral and do not require antibiotics; ensure diagnostic criteria for bacterial infection are met before prescribing 2
• Do not prescribe antibiotics for symptom duration < 10 days unless severe features are present (fever ≥ 39°C with purulent nasal discharge for ≥ 3 consecutive days) 3
• Using standard doses when high-dose therapy is indicated leads to treatment failure with resistant organisms 2

Adverse Effects

• Most common: Diarrhea (17–26%), diaper dermatitis (21–33%), nausea, vomiting 1, 2, 4
• The 14:1 ratio formulation (90/6.4 mg/kg/day) causes less diarrhea than other preparations 2, 3
• Hypersensitivity reactions: Rash, urticaria may occur 1
• Overall tolerability: Generally well tolerated; serious adverse events are rare 5

Renal Impairment

• Dose adjustment required in children with renal insufficiency; prolong dosing interval according to creatinine clearance 2
• Both amoxicillin and clavulanate are renally eliminated; accumulation risk exists without dose reduction 2